Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Claims 1-20 are presented for examination.
Claim Objections
Claim 1 is objected to because of the following informalities:
As per Claim 1, it further recites “outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes” in line 24-25 would be better as “outputting the sandwich panel mesh including the panel infill mesh and the face sheet meshes” because “a sandwich panel mesh” in line 24 cannot be ascertained whether the sandwich panel mesh that is output is the sandwich panel mesh formed by the mapped copies of the reference unit cell mesh or a different, second sandwich panel mesh.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
3. Claims 1-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor regards as the invention.
As per Claim 1, it recites the limitation “computing a second driver mesh of the mid-surface CAD geometry based at least in part on the density field” in line 10-11 and “an element size field that is computed based at least in part on the density field” in line 14-15, which is unclear what the limitation refers. The limitation “at least in part” is used as a coordinating conjunction to show an alternative between features which separates two distinct options indicating that a choice must be made between them. But there is no other alternative feature claimed for the “at least in part” alternative limitation: the claim recites no other basis, in addition to the density field, on which the second driver mesh or the element size field is computed. Examiner Interpretation: the limitation “based at least in part on the density field” is interpreted as requiring the density field to be a basis of the recited computation, without excluding additional unrecited bases, consistent with paragraph [0046] of the specification.
As per Claim 1, it further recites “outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes” in line 24-25 would be better as “outputting the sandwich panel mesh including the panel infill mesh and the face sheet meshes” because “a sandwich panel mesh” in line 24 because it cannot be ascertained whether the sandwich panel mesh that is output is the sandwich panel mesh formed by the mapped copies of the reference unit cell mesh or a different, second sandwich panel mesh, and the metes and bounds of the outputting step therefore cannot be fixed.
As per Claim 7, it additionally recites the limitation “computing a point set based at least in part on the element size field” in line 1-2. The limitation “at least in part” is used as a coordinating conjunction to show an alternative between features which separates two distinct options indicating that a choice must be made between them. But there is no other alternative feature claimed for the “at least in part” alternative limitation. Examiner Interpretation: the limitation “computing a point set based at least in part on the element size field” is interpreted as requiring the element size field to be a basis of the point set computation, without excluding additional unrecited bases, consistent with paragraph [0058] of the specification.
As per Claim 16, it recites the limitation “the panel infill structure is generated at least in part by: mapping a plurality of hexahedral elements to respective quadrilaterals included in a driver mesh to thereby obtain a sandwich panel mesh.” in line 9-11 and “the driver mesh is generated based at least in part on a density field computed using a topology optimization algorithm” in line 15-16. The limitation “at least in part” is used as a coordinating conjunction to show an alternative between features which separates two distinct options indicating that a choice must be made between them. But there is no other alternative feature claimed for the “at least in part” alternative limitation. Examiner Interpretation: the limitations “generated at least in part by” and “generated based at least in part on a density field” are interpreted as requiring the recited generating steps and the density field to be, respectively, part of the generation of the panel infill structure and a basis of the driver mesh generation, without excluding additional unrecited steps or bases, consistent with paragraphs [0046] and [0055] of the specification.
Claim 18 recites the limitation “the mid-surface CAD geometry” in line 3. There is insufficient antecedent basis for this limitation in the claim. Claim 16 recites only “a panel mid-surface of the sandwich panel” and never recites any mid-surface CAD geometry. To overcome this rejection, Applicant may consider amending claim 18 to recite “a direction locally orthogonal to a normal of the panel mid-surface”, MPEP 2173.05(e). Examiner Interpretation: the limitation “the mid-surface CAD geometry” is interpreted as computer-aided design geometry representing the panel mid-surface of the sandwich panel recited in claim 16, consistent with paragraph [0040] of the specification.
As per Claim 20, it recites the limitation “compute a second driver mesh of the mid-surface CAD geometry based at least in part on the density field” in line 10-11 and “an element size field that is computed based at least in part on the density field” in line 14-16, which is unclear what the limitation refers. The limitation “at least in part” is used as a coordinating conjunction to show an alternative between features which separates two distinct options indicating that a choice must be made between them. But there is no other alternative feature claimed for the “at least in part” alternative limitation: the claim recites no other basis, in addition to the density field, on which the second driver mesh or the element size field is computed. Examiner Interpretation: the limitation “based at least in part on the density field” is interpreted as requiring the density field to be a basis of the recited computation, without excluding additional unrecited bases, consistent with paragraph [0046] of the specification.
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
4. Claims 1-15 and 20 are rejected under 35 U.S.C. 101 because the claimed invention recites a judicial exception, is directed to that judicial exception, an abstract idea, as it has not been integrated into practical application and the claims further do not recite significantly more than the judicial exception.
(Step 1) The claim 1-15 is directed methods and fall within the statutory category of processes; and, the claim 20 is directed to an apparatus and falls within the statutory category of machines.
(Step 2A – Prong One) For the sake of identifying the abstract ideas, a copy of the claim is provided below. Abstract ideas are bolded.
Claim 1 and 20 recite:
providing a mid-surface computer-aided design (CAD) geometry representing a panel mid-surface of a sandwich panel, wherein the mid-surface CAD geometry has a 2-manifold form (insignificant extra-solution activity – data gathering and/or “field of use”);
generating a first driver mesh of the mid-surface CAD geometry, wherein the first driver mesh includes a first plurality of quadrilateral elements (under its broadest reasonable interpretation, a mental process that convers performance in the human mind or with the aid of pencil and paper including an observation, evaluation, judgment or opinion);
using a topology optimization algorithm that has one or more objective functions, generating a density field defined on the first driver mesh (under its broadest reasonable interpretation, a mathematical concept and a mental process that convers performance in the human mind or with the aid of pencil and paper including an observation, evaluation, judgment or opinion);
computing a second driver mesh of the mid-surface CAD geometry based at least in part on the density field, (under its broadest reasonable interpretation, a mathematical concept and a mental process that convers performance in the human mind or with the aid of pencil and paper including an observation, evaluation, judgment or opinion) wherein:
the second driver mesh includes a second plurality of quadrilateral elements; (insignificant extra-solution activity – data gathering and/or “field of use”) and
the second plurality of quadrilateral elements have respective element sizes specified by an element size field that is computed based at least in part on the density field; (insignificant extra-solution activity – data gathering and/or “field of use”)
providing a reference unit cell mesh that has a unit cell geometry configured to fit within a cube (insignificant extra-solution activity – data gathering), wherein the reference unit cell mesh includes a unit infill mesh and a pair of unit face sheet meshes at opposite ends of the unit infill mesh (insignificant extra-solution activity – data gathering and/or “field of use”);
mapping a plurality of copies of the reference unit cell mesh onto a respective plurality of hexahedral elements associated with the second plurality of quadrilateral elements (under its broadest reasonable interpretation, a mental process that convers performance in the human mind or with the aid of pencil and paper including an observation, evaluation, judgment or opinion), wherein the mapped copies of the reference unit cell mesh form a sandwich panel mesh that has a panel infill mesh interconnecting a pair of face sheet meshes (insignificant extra-solution activity – data gathering and/or “field of use”); and
outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes (insignificant extra-solution activity for the act of outputting itself).
Therefore, the limitations, under the broadest reasonable interpretation, have been identified to recite judicial exceptions, an abstract idea.
(Step 2A – Prong Two: integration into practical application) This judicial exception is not integrated into a practical application. In particular, the claims recite the following additional elements of “A computing device comprising: a processor configured to: receive a mid-surface computer-aided design (CAD) geometry representing a panel mid-surface of a sandwich panel” (Claim 20) which is recited at high level generality and recited so generally that they represent more than mere instruction to apply the judicial exception on a computer (see MPEP 2106.05(f)). The limitation can also be viewed as nothing more than an attempt to generally link the use of the judicial exception to the technological environment of a computer (see MPEP 2106.05(d)). Further the additional elements of “computer-aided design (CAD) geometry” is an insignificant extra-solution activity which is generally linking the use of a judicial exception to a particular technological environment or field of use (see MPEP 2106.05(h)).
Further Claims recite the limitation which is an insignificant extra-solution activity because it is a mere nominal or tangential addition to the claim, amounts to mere data gathering (see MPEP 2106.05(g)) and/or generally linking the use of a judicial exception to a particular technological environment or field of use (see MPEP 2106.05(h)): (Claim 1 and 20) “providing a mid-surface computer-aided design (CAD) geometry representing a panel mid-surface of a sandwich panel, wherein the mid-surface CAD geometry has a 2-manifold form (insignificant extra-solution activity – data gathering and/or “field of use”);
the second driver mesh includes a second plurality of quadrilateral elements; (insignificant extra-solution activity – data gathering and/or “field of use”) and
the second plurality of quadrilateral elements have respective element sizes specified by an element size field that is computed based at least in part on the density field; (insignificant extra-solution activity – data gathering and/or “field of use”)
providing a reference unit cell mesh that has a unit cell geometry configured to fit within a cube (insignificant extra-solution activity – data gathering), wherein the reference unit cell mesh includes a unit infill mesh and a pair of unit face sheet meshes at opposite ends of the unit infill mesh (insignificant extra-solution activity – data gathering and/or “field of use”);
wherein the mapped copies of the reference unit cell mesh form a sandwich panel mesh that has a panel infill mesh interconnecting a pair of face sheet meshes (insignificant extra-solution activity – data gathering and/or “field of use”);”.
Further the claims recite the limitation which insignificant extra-solution activity for the act of outputting itself, is equivalent to “apply it” and/or generally linking the use of a judicial exception to a particular technological environment or field of use (see MPEP 2106.05(h)): (Claim 1 and 20) “outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes (insignificant extra-solution activity for the act of outputting itself)”.
Even when viewed in combination, these additional elements do not integrate the recited judicial exception into a practical application and the claim is directed to the judicial exception.
(Step 2B - inventive concept) The claim(s) does/do not include additional elements that are sufficient to amount to significantly more than the judicial exception. As discussed above with respect to integration of the abstract idea into a practical application, the additional elements of “A computing device comprising: a processor configured to: receive a mid-surface computer-aided design (CAD) geometry representing a panel mid-surface of a sandwich panel” (Claim 20) which is recited at high level generality and recited so generally that they represent more than mere instruction to apply the judicial exception on a computer (see MPEP 2106.05(f)). The limitation can also be viewed as nothing more than an attempt to generally link the use of the judicial exception to the technological environment of a computer (see MPEP 2106.05(d)). Further the additional elements of “computer-aided design (CAD) geometry” is an insignificant extra-solution activity which is generally linking the use of a judicial exception to a particular technological environment or field of use (see MPEP 2106.05(h)).
Further as discussed above Claims 1 and 20 recite the limitation which is an insignificant extra-solution activity because it is a mere nominal or tangential addition to the claim, amounts to mere data gathering/outputting (see MPEP 2106.05(g)) which is the element that the courts have recognized as well-understood, routine, conventional activity (see MPEP 2106.05(d) II. i. Receiving or transmitting data over a network, e.g., using the Internet to gather data, Symantec, 838 F.3d at 1321, 120 USPQ2d at 1362 (utilizing an intermediary computer to forward information); TLI Communications LLC v. AV Auto. LLC, 823 F.3d 607, 610, 118 USPQ2d 1744, 1745 (Fed. Cir. 2016) (using a telephone for image transmission); OIP Techs., Inc., v. Amazon.com, Inc., 788 F.3d 1359, 1363, 115 USPQ2d 1090, 1093 (Fed. Cir. 2015) (sending messages over a network); buySAFE, Inc. v. Google, Inc., 765 F.3d 1350, 1355, 112 USPQ2d 1093, 1096 (Fed. Cir. 2014) (computer receives and sends information over a network); but see DDR Holdings, LLC v. Hotels.com, L.P., 773 F.3d 1245, 1258, 113 USPQ2d 1097, 1106 (Fed. Cir. 2014) (“Unlike the claims in Ultramercial, the claims at issue here specify how interactions with the Internet are manipulated to yield a desired result‐‐a result that overrides the routine and conventional sequence of events ordinarily triggered by the click of a hyperlink.” (emphasis added)); iv. Storing and retrieving information in memory, Versata Dev. Group, Inc. v. SAP Am., Inc., 793 F.3d 1306, 1334, 115 USPQ2d 1681, 1701 (Fed. Cir. 2015); OIP Techs., 788 F.3d at 1363, 115 USPQ2d at 1092-93): (Claim 1 and 20) “providing a mid-surface computer-aided design (CAD) geometry representing a panel mid-surface of a sandwich panel, wherein the mid-surface CAD geometry has a 2-manifold form (insignificant extra-solution activity – data gathering and/or “field of use”);
the second driver mesh includes a second plurality of quadrilateral elements; (insignificant extra-solution activity – data gathering and/or “field of use”) and
the second plurality of quadrilateral elements have respective element sizes specified by an element size field that is computed based at least in part on the density field; (insignificant extra-solution activity – data gathering and/or “field of use”)
providing a reference unit cell mesh that has a unit cell geometry configured to fit within a cube (insignificant extra-solution activity – data gathering), wherein the reference unit cell mesh includes a unit infill mesh and a pair of unit face sheet meshes at opposite ends of the unit infill mesh (insignificant extra-solution activity – data gathering and/or “field of use”);
wherein the mapped copies of the reference unit cell mesh form a sandwich panel mesh that has a panel infill mesh interconnecting a pair of face sheet meshes (insignificant extra-solution activity – data gathering and/or “field of use”);”.
Also the claims recite the limitation which insignificant extra-solution activity for the act of outputting itself , is equivalent to “apply it”, and/or generally linking the use of a judicial exception to a particular technological environment or field of use (see MPEP §2106.05(h)): (Claim 1 and 20) “outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes (insignificant extra-solution activity for the act of outputting itself)”.
Further dependent claims 2-15 recite:
2. The method of claim 1, wherein: the sandwich panel mesh is output to an additive manufacturing device; (insignificant extra-solution activity - “apply it”) and
the method further comprises additively manufacturing the sandwich panel at the additive manufacturing device according to the sandwich panel mesh. (insignificant extra-solution activity - “apply it”)
3. The method of claim 1, wherein the copies of the reference unit cell mesh are mapped onto the hexahedral elements using a plurality of basis functions that are defined on each of the second plurality of quadrilateral elements and that are configured to conform the copies of the reference unit cell mesh to the hexahedral elements by adjusting the respective sizes and shapes of the copies of the reference unit cell mesh. (a mental process)
4. The method of claim 1, wherein executing the topology optimization algorithm includes solving one or more physics boundary value problems by performing one or more numerical methods over a plurality of topology optimization iterations. (a mental process)
5. The method of claim 4, wherein the topology optimization algorithm is a Solid Isotropic Material with Penalization (SIMP) algorithm, a Rational Approximation of Material Properties (RAMP) algorithm, an Evolutionary Structural Optimization (ESO) algorithm, a Bi-Directional Evolutionary Structural Optimization (BESO) algorithm, a Level Set Topology Optimization (LSTO) algorithm, or a Phase Field Topology Optimization (PFTO) algorithm. (insignificant extra-solution activity – data gathering and/or “field of use”)
6. The method of claim 1, further comprising computing the element size field using a density mapping function that maps each of a plurality of density values included in the density field to either a first target element size or a second target element size. (a mental process)
7. The method of claim 1, further comprising computing a point set based at least in part on the element size field, (a mental process) wherein:
the point set includes a plurality of points distributed over the mid-surface CAD geometry; (insignificant extra-solution activity – data gathering and/or “field of use”)
the element size field specifies distances between neighboring points included in the point set; and (insignificant extra-solution activity – data gathering and/or “field of use”)
computing the second driver mesh includes: computing a plurality of triangular cells from the point set via Delaunay triangulation; (a mental process) and
combining the triangular cells into the second plurality of quadrilateral elements. (a mental process)
8. The method of claim 1, further comprising smoothing the sandwich panel mesh in a direction locally orthogonal to a normal of the mid-surface CAD geometry. (a mental process)
9. The method of claim 8, wherein the sandwich panel mesh is smoothed over a plurality of smoothing iterations. (repetition of a mental process)
10. The method of claim 1, further comprising:
receiving one or more loads applied to the sandwich panel and one or more boundary conditions of the sandwich panel; and (insignificant extra-solution activity – data gathering and/or “field of use”)
computing the density field based at least in part on the one or more loads and the one or more boundary conditions. (a mental process
11. The method of claim 10, wherein the one or more loads include a mechanical force, a mechanical torque, a heat flux, and/or an electrical current. (insignificant extra-solution activity – data gathering and/or “field of use”)
12. The method of claim 10, wherein the one or more boundary conditions include an enforced translational displacement boundary condition, an enforced rotational displacement boundary condition, an enforced temperature boundary condition, and/or an enforced electric field boundary condition. (insignificant extra-solution activity – data gathering and/or “field of use”)
13. The method of claim 1, wherein the one or more objective functions include an elastic strain energy objective function, a thermal energy objective function, an electrical energy objective function, and/or an acoustic energy objective function. (insignificant extra-solution activity – data gathering and/or “field of use”)
14. The method of claim 1, wherein the topology optimization algorithm is subjected to one or more constraints that are each selected from the group consisting of a mass constraint, a volume constraint, an overhang constraint, a minimum wall thickness constraint, and a closed cell structure constraint. (insignificant extra-solution activity – data gathering and/or “field of use”)
15. The method of claim 1, further comprising stitching together the mapped copies of the reference unit cell mesh (a mental process at least in part by:
identifying one or more pairs of cell mesh nodes included in the sandwich panel mesh that are duplicate nodes; (a mental process) and
updating the sandwich panel mesh by deleting a respective cell mesh node from each of the one or more identified pairs. (a mental process)
Considering the claim both individually and in combination, there is no element or combination of elements recited contains any “inventive concept” or adds “significantly more” to transform the abstract concept into a patent-eligible application.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
5. Claims 1-3, 6, 15-17 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Musuvathy (US 2015/0193559 A1) in view of Nguyen (“Conformal Lattice Structure Design and Fabrication”), further in view of De Lange (US 2019/0205499 A1) and Marschall (“Boundary conformal design of laser sintered sandwich cores and simulation of graded lattice cells using a forward homogenization approach”).
As per Claim 1 and 20, Musuvathy teaches A method of generating a panel infill lattice geometry of a panel (Musuvathy [0050] “the system receives a solid model containing a plurality of boundary surfaces 150 for a void region”: a solid CAD model is received by the computer-implemented method, which generates an internal lattice-cell infill geometry for its void region)/ computing device comprising: a processor configured to: (Musuvathy [0027] “The data processing system depicted includes a processor 102 connected to a level two cache/bridge 104, which is connected in turn to a local system bus 106”: the lattice design method is implemented on a data processing system having a processor configured to perform it), comprising:
providing a reference unit cell mesh that has a unit cell geometry configured to fit within a cube (Musuvathy [0041]; Musuvathy [0053] “each lattice cell is a hexahedron that is homeomorphic to the lattice cell 166. Any volumetric mesh generation process can be used for grid creation”: the cell template is defined within the cubic reference lattice cell 166, so the unit cell geometry fits within a cube, and the layout grid holding its copies may come from any volumetric mesh generation process); and
mapping a plurality of copies of the reference unit cell mesh onto a respective plurality of hexahedral elements (Musuvathy [0042] “The layout generation is performed with hexahedral elements, and a lattice template is defined within a lattice cell 166. Each of the hexahedral elements is replaced with a transformed template lattice skeleton”: a copy of the reference unit cell template is transformed into, i.e. mapped onto, each hexahedral element of the layout, forming the infill lattice mesh). In particular, Musuvathy teaches a computer-implemented method that receives a solid CAD model, creates a hexahedral lattice-cell layout over the region to be infilled, and replaces each hexahedral element with a transformed copy of a cube-fitting reference unit cell template to form the infill lattice geometry, expressly leaving the layout-mesh generation process open to any volumetric mesh generation process.
However, Musuvathy fails to teach explicitly providing a mid-surface computer-aided design (CAD) geometry representing a panel mid-surface of a sandwich panel, wherein the mid-surface CAD geometry has a 2-manifold form;
generating a first driver mesh of the mid-surface CAD geometry, wherein the first driver mesh includes a first plurality of quadrilateral elements;
using a topology optimization algorithm that has one or more objective functions, generating a density field defined on the first driver mesh;
computing a second driver mesh of the mid-surface CAD geometry based at least in part on the density field, wherein:
the second driver mesh includes a second plurality of quadrilateral elements; and
the second plurality of quadrilateral elements have respective element sizes specified by an element size field that is computed based at least in part on the density field;
wherein the reference unit cell mesh includes a unit infill mesh and a pair of unit face sheet meshes at opposite ends of the unit infill mesh;
… hexahedral elements associated with the second plurality of quadrilateral elements, wherein the mapped copies of the reference unit cell mesh form a sandwich panel mesh that has a panel infill mesh interconnecting a pair of face sheet meshes; and
outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes.
Nguyen teaches providing a mid-surface computer-aided design (CAD) geometry representing a panel mid-surface of a sandwich panel, wherein the mid-surface CAD geometry has a 2-manifold form (Nguyen §2.1, pg. 142 “The input to the algorithm may be a CAD solid model of the part, a surface model of the part, or a triangulated surface model (STL file) of the part”: the conformal meshing algorithm is driven by a provided CAD surface model (a 2-manifold surface geometry) which serves as the reference surface of the panel to be reinforced; applied to the sandwich panel of the combination set out below, this driving reference surface represents the panel mid-surface), and
generating a first driver mesh of the mid-surface CAD geometry, wherein the first driver mesh includes a first plurality of quadrilateral elements (Nguyen §2, pg. 141 “In 2-D, the mesh consists of a set of connected quadrilaterals. In 3-D the mesh consists of hexahedra (6-sided volume elements with planar sides)”: the mesh imposed on the driving surface is a mesh of connected quadrilateral elements; Nguyen §2.2, pg. 143 “This step of the algorithm imposes a surface parameterization on the region of the part that will be reinforced [20]. The same parameterization is transferred to the offset surface. Finally, a lofted volume is constructed from the original surface to the offset surface”: the driver mesh is generated on the provided surface geometry itself, whose parameterization drives the loft and the subsequent division of the lofted volume into the hexahedral elements), and
hexahedral elements associated with the second plurality of quadrilateral elements (Nguyen §2.2, pg. 143: the parameterization imposed on the surface is transferred to the offset surface and the lofted volume between them is divided into hexahedral elements, so each quadrilateral element of the surface driver mesh corresponds to, and is thereby associated with, a hexahedral volume element of the divided loft, an association that follows from the loft construction; in the combination the density-sized quadrilateral elements of the second driver mesh carry that same association). In particular, Nguyen teaches generating a conformal hexahedral mesh for cellular-structure placement by providing a 2-manifold surface geometry of the part, imposing a surface parameterization (a quadrilateral driver mesh) on that surface, lofting a tri-parameter volume from the surface to its offset, and dividing the lofted volume into hexahedral elements of a selected element size, so that each quadrilateral surface element is associated with a hexahedral volume element.
Musuvathy and Nguyen are analogous art because they are both from the same field of endeavor as the claimed invention, computer-aided generation of conformal lattice infill meshes for additively manufactured structural components (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate Nguyen into Musuvathy's invention for the purpose of Musuvathy's template-based lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142).
This rationale is the use of a known technique (imposing a surface parameterization on a part surface and dividing the lofted volume to its offset into hexahedral elements, Nguyen §2.2, pg. 143) to improve a similar device (a template-based lattice generator that replaces each hexahedral element of a layout with a transformed unit cell template, Musuvathy [0042]) in the same way, MPEP 2143(I)(C); KSR Int'l Co. v. Teleflex Inc.
However, Musuvathy as modified by Nguyen fails to teach explicitly using a topology optimization algorithm that has one or more objective functions, generating a density field defined on the first driver mesh;
computing a second driver mesh of the mid-surface CAD geometry based at least in part on the density field, wherein:
the second driver mesh includes a second plurality of quadrilateral elements; and
the second plurality of quadrilateral elements have respective element sizes specified by an element size field that is computed based at least in part on the density field;
wherein the reference unit cell mesh includes a unit infill mesh and a pair of unit face sheet meshes at opposite ends of the unit infill mesh;
wherein the mapped copies of the reference unit cell mesh form a sandwich panel mesh that has a panel infill mesh interconnecting a pair of face sheet meshes; and
outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes.
De Lange teaches using a topology optimization algorithm that has one or more objective functions, generating a density field defined on the first driver mesh (De Lange [0027] “the entire design space is considered a homogenous lattice structure, and topology optimization is used to determine a density distribution for the lattice structure at each location in the design space”: a topology optimization algorithm generates a density field defined over the meshed design space, in the combination, over the driver mesh of Musuvathy as modified by Nguyen discretizing the panel), and
computing a second driver mesh of the mid-surface CAD geometry based at least in part on the density field, wherein: the second driver mesh includes a second plurality of quadrilateral elements; and the second plurality of quadrilateral elements have respective element sizes specified by an element size field that is computed based at least in part on the density field (De Lange [0032] “For each lattice zone, the geometry size of the latice structure is determined such that the actual density of the lattice cell matches the local density derived from topology optimization. Using a lattice sizing curve and the local density distribution, the local sizing of the lattice trusses for each lattice zone is defined”: topology optimization by its nature optimizes one or more objective functions (in De Lange, the part's stiffness); for each lattice zone a geometry size of the lattice structure is determined from the local optimized density, which in De Lange is realized as the sizing of the trusses within cells of chosen outer dimensions and reading that per-zone, density-derived geometry size as the element size applied to the hexahedral elements of the conformal mesh, and so to their quadrilateral surface elements, is an inference drawn in the combination (i.e., the “element size field that is computed based at least in part on the density field” as claimed). In particular, De Lange teaches performing topology optimization over a design space treated as homogeneous lattice material, with the density field computed on the finite-element discretization of the design space, and then determining, for each lattice zone, a geometry size of the lattice structure from the local optimized density so that the actual density of the lattice cell matches it, that is, computing a per-zone size field from the density field; applied in the combination as the element size of the hexahedral elements (and their associated quadrilateral surface elements) of the conformal mesh of Musuvathy as modified by Nguyen, that size field produces the second driver mesh.
Musuvathy, Nguyen, and De Lange are analogous art because they are all from the same field of endeavor as the claimed invention, computer-aided generation of conformal lattice infill meshes for additively manufactured structural components (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate De Lange into Musuvathy as modified by Nguyen's invention for the purpose of Musuvathy's conformal template-lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142) and to provide lattice cells sized such that the actual density of the lattice cell matches the local density derived from topology optimization (De Lange: [0032]).
This rationale is the combination of prior art elements according to known methods to yield predictable results, MPEP 2143(I)(A); KSR Int'l Co. v. Teleflex Inc.
However, Musuvathy as modified by Nguyen and De Lange fails to teach explicitly wherein the reference unit cell mesh includes a unit infill mesh and a pair of unit face sheet meshes at opposite ends of the unit infill mesh;
wherein the mapped copies of the reference unit cell mesh form a sandwich panel mesh that has a panel infill mesh interconnecting a pair of face sheet meshes; and
outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes.
Marschall teaches wherein the mapped copies of the reference unit cell mesh form a sandwich panel mesh that has a panel infill mesh interconnecting a pair of face sheet meshes (Marschall §2.1, pg. 3 “ With the extracted node information of the hexahedron element and lines, a UC, such as sc bcc and fcc, can be interpolated based on the hexahedral eight-node isoparametric shape function, similar to that in [10, 11]. A sandwich core with different lattice cells and face sheets was joined to form a single triangular mesh.”: the unit cells interpolated into the hexahedral core elements and the two face sheets are joined into a single sandwich panel mesh in which the cellular infill mesh interconnects the pair of face sheet meshes); and
outputting a sandwich panel mesh including the panel infill mesh and the face sheet meshes (Marschall §2.1, pg. 3: the joined single mesh of the celled core and the face sheets is the output sandwich panel mesh from which the panel is laser sintered). In particular, Marschall teaches exactly the claimed article and mesh architecture: a sandwich panel whose core is hexahedrally meshed in CAD, whose unit cells are interpolated into the hexahedral elements by shape functions, and whose celled core and face sheets are joined into, and output as, a single sandwich panel mesh.
Musuvathy, Nguyen, De Lange, and Marschall are analogous art because they are all from the same field of endeavor as the claimed invention, computer-aided generation of conformal lattice infill meshes for additively manufactured structural components (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate Marschall into Musuvathy as modified by Nguyen and De Lange's invention for the purpose of Musuvathy's conformal template-lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142), to provide lattice cells sized such that the actual density of the lattice cell matches the local density derived from topology optimization (De Lange: [0032]), and to provide a boundary conforming lattice cell design that avoids uniform, incompletely trimmed lattice structures in a laser-sintered sandwich panel (Marschall: §2.1, pg. 3).
This rationale is the combination of prior art elements according to known methods to yield predictable results, MPEP 2143(I)(A); KSR Int'l Co. v. Teleflex Inc.
However, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein the reference unit cell mesh includes a unit infill mesh and a pair of unit face sheet meshes at opposite ends of the unit infill mesh.
Marschall teaches that each truss unit cell of the core is generated from the eight nodes of its first-order hexahedral core element and that the celled core and the face sheets are then joined to form a single mesh (Marschall §2.1, pg. 3 “Based on the eight resulting element nodes of the first-order hexahedron element of the sandwich core, lines were generated after the truss-based unit cells”; Marschall §2.1, pg. 3 “A sandwich core with different lattice cells and face sheets was joined to form a single triangular mesh”), and the only difference is that the face sheet meshes are joined to the celled core at the panel level rather than being carried as a pair of unit face sheet meshes at opposite ends of each unit infill mesh (Marschall §2.1, pg. 3).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to carry the two face sheet mesh portions that bound each hexahedral core element within the reference unit cell mesh, at opposite ends of the unit infill mesh, so that the mapped unit cell copies join into the same single sandwich panel mesh of celled core and face sheets, since it has been held that shifting the position of the face sheet mesh portions would not have modified the operation of the device (In re Japikse, 181 F.2d 1019 (CCPA 1950); MPEP 2144.04(VI)(C)).
As per Claim 2, Musuvathy fails to teach explicitly wherein: the sandwich panel mesh is output to an additive manufacturing device; and the method further comprises additively manufacturing the sandwich panel at the additive manufacturing device according to the sandwich panel mesh.
De Lange teaches wherein: the sandwich panel mesh is output to an additive manufacturing device (De Lange [0031] “At the end of this process, the model may be submitted to the additive manufacturing machine for 3D printing”: the finished cellular mesh model is output to an additive manufacturing device); and the method further comprises additively manufacturing the sandwich panel at the additive manufacturing device according to the sandwich panel mesh (De Lange [0037] “the lattice structures and the bulk structures of the structural component are printed using a three-dimensional printer depositing or otherwise forming successive layers of material into the structural component”: the component, which in the combination is the sandwich panel of Marschall as applied to claim 1 above, is additively manufactured according to the submitted mesh model).
As per Claim 3, Musuvathy fails to teach explicitly wherein the copies of the reference unit cell mesh are mapped onto the hexahedral elements using a plurality of basis functions that are defined on each of the second plurality of quadrilateral elements and that are configured to conform the copies of the reference unit cell mesh to the hexahedral elements by adjusting the respective sizes and shapes of the copies of the reference unit cell mesh.
Marschall teaches wherein the copies of the reference unit cell mesh are mapped onto the hexahedral elements using a plurality of basis functions that are defined on each of the second plurality of quadrilateral elements and that are configured to conform the copies of the reference unit cell mesh to the hexahedral elements by adjusting the respective sizes and shapes of the copies of the reference unit cell mesh (Marschall §2.1, pg. 3: the hexahedral eight-node isoparametric shape functions (i.e., the “plurality of basis functions” as claimed), defined on the element including its quadrilateral faces that belong to the driver mesh, interpolate each unit cell into its hexahedron and thereby conform the size and shape of the cell copy to that element).
As per Claim 6, Musuvathy fails to teach explicitly further comprising computing the element size field using a density mapping function that maps each of a plurality of density values included in the density field to either a first target element size or a second target element size.
De Lange teaches computing the element size field using a density mapping function that maps each of a plurality of density values included in the density field to either a first target element size or a second target element size (De Lange [0030] “a first density limit, below which no material should be printed (e.g., a VOID zone for densities below 0.25) and a second density limit is set above which bulk material should be printed to avoid powder trapping and coagulation (e.g., a BULK zone for densities above 0.80) are set”: a density mapping function with first and second density limits maps each local density value of the density field into one of the discrete size regimes bounding the printable lattice cells; De Lange [0032]: within the lattice regime the sizing curve maps each density value to a geometry size of the lattice structure).
As per Claim 15, Musuvathy fails to teach explicitly further comprising stitching together the mapped copies of the reference unit cell mesh at least in part by: identifying one or more pairs of cell mesh nodes included in the sandwich panel mesh that are duplicate nodes; and updating the sandwich panel mesh by deleting a respective cell mesh node from each of the one or more identified pairs.
Nguyen teaches stitching together the mapped copies of the reference unit cell mesh at least in part by: identifying one or more pairs of cell mesh nodes included in the sandwich panel mesh that are duplicate nodes; and updating the sandwich panel mesh by deleting a respective cell mesh node from each of the one or more identified pairs (Nguyen §2.2, pg. 143 “Nodes from neighboring regions may be moved and merged to achieve matched boundaries”: merging coincident boundary nodes of neighboring mesh regions identifies each duplicate node pair and collapses it to a single node thus one node of each identified pair is deleted from the stitched mesh).
As per Claim 16, Musuvathy teaches the plurality of hexahedral elements specify respective sizes and shapes of the unit cell structures (Musuvathy [0042]: each hexahedral element of the layout is replaced with a transformed copy of the unit cell template, so the element specifies the size and shape of its unit cell).
However, Musuvathy fails to teach explicitly A sandwich panel comprising:
a first face sheet; a second face sheet; and
a panel infill structure, wherein:
the panel infill structure includes a plurality of unit cell structures that connect the first face sheet to the second face sheet;
each of the unit cell structures has a main axis that is locally normal to a panel mid-surface of the sandwich panel; and
the panel infill structure is generated at least in part by:
mapping a plurality of hexahedral elements to respective quadrilaterals included in a driver mesh to thereby obtain a sandwich panel mesh, wherein:
…
the driver mesh is generated based at least in part on a density field computed using a topology optimization algorithm; and
as specified by the sandwich panel mesh, additively manufacturing the sandwich panel, including the first face sheet, the second face sheet, and the panel infill structure.
Nguyen teaches the panel infill structure is generated at least in part by: mapping a plurality of hexahedral elements to respective quadrilaterals included in a driver mesh to thereby obtain a sandwich panel mesh (Nguyen §2, pg. 141; Nguyen §2.2, pg. 143: each hexahedral element of the lofted volume divided from the parameterized driving surface corresponds to a quadrilateral element of the surface driver mesh and receives a mapped unit cell as set out for claim 1, yielding the panel mesh; that the panel is a sandwich panel with face sheets is supplied by Marschall as set out below).
Musuvathy and Nguyen are analogous art because they are both from the same field of endeavor as the claimed invention, computer-aided generation of conformal lattice infill meshes for additively manufactured structural components (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate Nguyen into Musuvathy's invention for the purpose of Musuvathy's template-based lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142).
This rationale is the use of a known technique (imposing a surface parameterization on a part surface and dividing the lofted volume to its offset into hexahedral elements, Nguyen §2.2, pg. 143) to improve a similar device (a template-based lattice generator that replaces each hexahedral element of a layout with a transformed unit cell template, Musuvathy [0042]) in the same way, MPEP 2143(I)(C); KSR Int'l Co. v. Teleflex Inc.
However, Musuvathy as modified by Nguyen fails to teach explicitly A sandwich panel comprising:
a first face sheet; a second face sheet; and
a panel infill structure, wherein:
the panel infill structure includes a plurality of unit cell structures that connect the first face sheet to the second face sheet;
each of the unit cell structures has a main axis that is locally normal to a panel mid-surface of the sandwich panel; and
the driver mesh is generated based at least in part on a density field computed using a topology optimization algorithm,
the driver mesh is generated based at least in part on a density field computed using a topology optimization algorithm; and
as specified by the sandwich panel mesh, additively manufacturing the sandwich panel, including the first face sheet, the second face sheet, and the panel infill structure.
De Lange teaches the driver mesh is generated based at least in part on a density field computed using a topology optimization algorithm (De Lange [0027]; De Lange [0032]: the geometry size of the lattice structure in each zone is determined from the density field determined by topology optimization, which in the combination sizes the driver mesh of the conformal mesh of Musuvathy as modified by Nguyen, as set out for claim 1).
Musuvathy, Nguyen, and De Lange are analogous art because they are all from the same field of endeavor as the claimed invention, computer-aided generation of conformal lattice infill meshes for additively manufactured structural components (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate De Lange into Musuvathy as modified by Nguyen's invention for the purpose of Musuvathy's conformal template-lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142) and to provide lattice cells sized such that the actual density of the lattice cell matches the local density derived from topology optimization (De Lange: [0032]).
However, Musuvathy as modified by Nguyen and De Lange fails to teach explicitly A sandwich panel comprising:
a first face sheet; a second face sheet; and
a panel infill structure, wherein:
the panel infill structure includes a plurality of unit cell structures that connect the first face sheet to the second face sheet;
each of the unit cell structures has a main axis that is locally normal to a panel mid-surface of the sandwich panel; and
as specified by the sandwich panel mesh, additively manufacturing the sandwich panel, including the first face sheet, the second face sheet, and the panel infill structure.
Marschall teaches A sandwich panel comprising: a first face sheet; a second face sheet; and a panel infill structure (Marschall §2.1, pg. 3: the laser-sintered sandwich beams and fairing consist of two face sheets joined by a boundary-conformal lattice core, the panel infill structure); the panel infill structure includes a plurality of unit cell structures that connect the first face sheet to the second face sheet (Marschall §2.6, pg. 6: the unit cell structures of the core connect the first and second face sheets);
each of the unit cell structures has a main axis that is locally normal to a panel mid-surface of the sandwich panel (Marschall §4.3, pg. 9 “Based on the FE mesh shown in Fig. 10a, a multi-curved lattice design with non-periodical mixed lattice cells (bcc, sc-bcc, and sP) is generated”: the boundary-conformal cells of the multi-curved panel are generated within hexahedral core elements spanning face sheet to face sheet, so each cell's through-thickness main axis is read as lying locally normal to the panel's mid-surface; this reading is an inference from the cell construction, corroborated by Nguyen's loft from the driving surface to its offset as applied to claim 1 above, under which cells placed in the lofted volume have their through-thickness axis locally normal to that surface by construction); and
as specified by the sandwich panel mesh, additively manufacturing the sandwich panel, including the first face sheet, the second face sheet, and the panel infill structure (Marschall §2.1, pg. 3; Marschall §2.2, pg. 3 “The specimens were produced upright in a z-oriented position”: the joined single mesh of core cells and face sheets is the mesh from which the complete sandwich panel specimens are laser sintered, that is, additively manufactured as specified by the sandwich panel mesh).
Musuvathy, Nguyen, De Lange, and Marschall are analogous art because they are all from the same field of endeavor as the claimed invention, computer-aided generation of conformal lattice infill meshes for additively manufactured structural components (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate Marschall into Musuvathy as modified by Nguyen and De Lange's invention for the purpose of Musuvathy's conformal template-lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142), to provide lattice cells sized such that the actual density of the lattice cell matches the local density derived from topology optimization (De Lange: [0032]), and to provide a boundary conforming lattice cell design that avoids uniform, incompletely trimmed lattice structures in a laser-sintered sandwich panel (Marschall: §2.1, pg. 3).
Examiner’s Note: Claim 16 defines the sandwich panel in part by its process of generation (“is generated at least in part by ...”). Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself; the patentability of a product does not depend on its method of production (MPEP 2113). The process limitations are nonetheless fully addressed over the combination as set out above and for claim 1.
As per Claim 17, Musuvathy fails to teach explicitly wherein the topology optimization algorithm is a Solid Isotropic Material with Penalization (SIMP) algorithm, a Rational Approximation of Material Properties (RAMP) algorithm, an Evolutionary Structural Optimization (ESO) algorithm, a Bi-Directional Evolutionary Structural Optimization (BESO) algorithm, a Level Set Topology Optimization (LSTO) algorithm, or a Phase Field Topology Optimization (PFTO) algorithm.
De Lange teaches wherein the topology optimization algorithm is a Solid Isotropic Material with Penalization (SIMP) algorithm, a Rational Approximation of Material Properties (RAMP) algorithm, an Evolutionary Structural Optimization (ESO) algorithm, a Bi-Directional Evolutionary Structural Optimization (BESO) algorithm, a Level Set Topology Optimization (LSTO) algorithm, or a Phase Field Topology Optimization (PFTO) algorithm (De Lange [0029] “The topology optimization may utilize solid isotropic material with penalization (SIMP) material laws, or another topology optimization scheme”: the SIMP alternative of the recited list is expressly taught; the claim recites the algorithms in the alternative, so teaching the SIMP member meets the limitation).
6. Claims 4, 5, 10-14 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Musuvathy in view of Nguyen, further in view of De Lange, further in view of Marschall, further in view of Sigmund (“A 99 line topology optimization code written in Matlab”).
Musuvathy as modified by Nguyen, De Lange, and Marschall teaches most all the instant invention as applied to claims 1-3, 6, 15-17 and 20 above.
As per Claim 4, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein executing the topology optimization algorithm includes solving one or more physics boundary value problems by performing one or more numerical methods over a plurality of topology optimization iterations.
Sigmund teaches wherein executing the topology optimization algorithm includes solving one or more physics boundary value problems by performing one or more numerical methods over a plurality of topology optimization iterations (Sigmund §2, pg. 121 “
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“ : the equilibrium system KU = F is the finite-element discretization of the static elasticity boundary value problem (a numerical method) solved within the optimization; Sigmund §3, pg. 122 “Other variables as well as boundary conditions are defined in the Matlab code itself and can be edited if needed. For each iteration in the topology optimization loop, the code generates a picture of the current density distribution”: the boundary value problem is solved anew at each iteration of the topology optimization loop; Sigmund §3.1, pg. 122 “The main loop is terminated if the change in design variables (change determined in line 30) is less than 1 percent”: the main loop otherwise repeats, so the steps run over a plurality of topology optimization iterations until convergence). In particular, Sigmund teaches a topology optimization code whose main loop repeats finite-element solution of the discretized elasticity boundary value problem, sensitivity analysis, and design-variable update over a plurality of iterations until the design converges.
Musuvathy, Nguyen, De Lange, Marschall, and Sigmund are analogous art because they are all reasonably pertinent to the problem faced by the inventor, computing a density field over the panel by topology optimization from the loads and boundary conditions applied to the panel (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate Sigmund into Musuvathy as modified by Nguyen, De Lange, and Marschall's invention for the purpose of Musuvathy's conformal template-lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142), to provide lattice cells sized such that the actual density of the lattice cell matches the local density derived from topology optimization (De Lange: [0032]), to provide a boundary conforming lattice cell design that avoids uniform, incompletely trimmed lattice structures in a laser-sintered sandwich panel (Marschall: §2.1, pg. 3), and to provide a compact and efficient optimality-criteria implementation in which the value of the Lagrangian multiplier that satisfies the volume constraint can be found by a bi-sectioning algorithm (Sigmund: Abstract, pg. 120; §1, pg. 121; §3.2, pg. 123).
As per Claim 5, Musuvathy as modified by Nguyen, De Lange, and Marschall teaches wherein the topology optimization algorithm is a Solid Isotropic Material with Penalization (SIMP) algorithm, a Rational Approximation of Material Properties (RAMP) algorithm, an Evolutionary Structural Optimization (ESO) algorithm, a Bi-Directional Evolutionary Structural Optimization (BESO) algorithm, a Level Set Topology Optimization (LSTO) algorithm, or a Phase Field Topology Optimization (PFTO) algorithm (De Lange [0029]: the SIMP alternative of the recited list is expressly taught, and the claim recites the algorithms in the alternative, so teaching the SIMP member meets the limitation).
As per Claim 10, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly further comprising: receiving one or more loads applied to the sandwich panel and one or more boundary conditions of the sandwich panel; and computing the density field based at least in part on the one or more loads and the one or more boundary conditions.
Sigmund teaches receiving one or more loads applied to the sandwich panel and one or more boundary conditions of the sandwich panel (Sigmund §3, pg. 122 “The default boundary conditions correspond to half of the “MBB-beam” (Fig. 1). The load is applied vertically in the upper left corner and there is symmetric boundary conditions along the left edge and the structure is supported horizontally in the lower right corner”: the optimization receives the applied load and the boundary conditions of the structure being designed, in the combination, of the sandwich panel); and
computing the density field based at least in part on the one or more loads and the one or more boundary conditions (Sigmund §2, pg. 121: the displacement field entering the compliance objective is solved from the applied loads and supports, so the optimized density distribution is computed from both).
As per Claim 11, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein the one or more loads include a mechanical force, a mechanical torque, a heat flux, and/or an electrical current.
Sigmund teaches wherein the one or more loads include a mechanical force, a mechanical torque, a heat flux, and/or an electrical current (Sigmund §3, pg. 122: the vertically applied load on the beam is a mechanical force).
As per Claim 12, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein the one or more boundary conditions include an enforced translational displacement boundary condition, an enforced rotational displacement boundary condition, an enforced temperature boundary condition, and/or an enforced electric field boundary condition.
Sigmund teaches wherein the one or more boundary conditions include an enforced translational displacement boundary condition, an enforced rotational displacement boundary condition, an enforced temperature boundary condition, and/or an enforced electric field boundary condition (Sigmund §3.4, pg. 123 “Supports are implemented by eliminating fixed degrees of freedom from the linear equations”: supports fix translational degrees of freedom of the structure; Examiner's Note - “enforced translational displacement boundary condition” corresponds to Sigmund's fixed degrees of freedom because eliminating a fixed translational degree of freedom from the equilibrium equations enforces a zero translational displacement at that node.).
As per Claim 13, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein the one or more objective functions include an elastic strain energy objective function, a thermal energy objective function, an electrical energy objective function, and/or an acoustic energy objective function.
Sigmund teaches wherein the one or more objective functions include an elastic strain energy objective function, a thermal energy objective function, an electrical energy objective function, and/or an acoustic energy objective function (Sigmund §2, pg. 121 “A topology optimization problem based on the power-law approach, where the objective is to minimize compliance can be written as”: the objective function of the optimization is the compliance of the statically loaded structure; Examiner's Note - “elastic strain energy objective function” corresponds to Sigmund's compliance objective because the compliance c(x) of the statically loaded linear-elastic structure equals twice its elastic strain energy).
As per Claim 14, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein the topology optimization algorithm is subjected to one or more constraints that are each selected from the group consisting of a mass constraint, a volume constraint, an overhang constraint, a minimum wall thickness constraint, and a closed cell structure constraint.
Sigmund teaches wherein the topology optimization algorithm is subjected to one or more constraints that are each selected from the group consisting of a mass constraint, a volume constraint, an overhang constraint, a minimum wall thickness constraint, and a closed cell structure constraint (Sigmund §2, pg. 121 “
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” : the optimization problem is subjected to the constraint V(x)/V0 = f, a volume constraint, which is a member of the recited Markush group; Sigmund §3.2, pg. 123 “the value of the Lagrangian multiplier that satisfies the volume constraint can be found by a bi-sectioning algorithm (lines 40-48)”: the optimizer expressly enforces the volume constraint on the topology optimization).
As per Claim 19, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein generating the sandwich panel mesh further includes: receiving one or more loads applied to the sandwich panel and one or more boundary conditions applied to the sandwich panel; and computing the density field based at least in part on the one or more loads and the one or more boundary conditions.
Sigmund teaches wherein generating the sandwich panel mesh further includes: receiving one or more loads applied to the sandwich panel and one or more boundary conditions applied to the sandwich panel (Sigmund §3, pg. 122: the optimization receives the applied load and the boundary conditions of the panel structure); and
computing the density field based at least in part on the one or more loads and the one or more boundary conditions (Sigmund §2, pg. 121: the optimized density distribution is computed from the applied loads and boundary conditions).
Examiner’s Note: These are process limitations of the product claim; determination of patentability is based on the product itself (MPEP 2113), and the limitations are in any event fully addressed over the combination as set out above.
7. Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Musuvathy in view of Nguyen, further in view of De Lange, further in view of Marschall, further in view of Remacle (“A frontal Delaunay quad mesh generator using the L∞ norm”).
Musuvathy as modified by Nguyen, De Lange, and Marschall teaches most all the instant invention as applied to claims 1-3, 6, 15-17 and 20 above.
As per Claim 7, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly computing a point set based at least in part on the element size field, wherein: the point set includes a plurality of points distributed over the mid-surface CAD geometry; the element size field specifies distances between neighboring points included in the point set; and computing the second driver mesh includes: computing a plurality of triangular cells from the point set via Delaunay triangulation; and combining the triangular cells into the second plurality of quadrilateral elements.
Remacle teaches further comprising computing a point set based at least in part on the element size field, wherein: the point set includes a plurality of points distributed over the mid-surface CAD geometry; the element size field specifies distances between neighboring points included in the point set (Remacle §5, pg. 12 “As it is based on a Delaunay kernel, a valid mesh is maintained at every stage of the process. Yet, some kind of front is defined in the triangulation and points are inserted in a frontal manner. The process stops when every element of the mesh has the right size according to the size field δ(x)”: a point set is computed over the meshed surface with the point spacing governed by the prescribed size field, the element size field specifying the distances between neighboring inserted points and in the combination the points are distributed over the mid-surface CAD geometry driving the panel mesh);
computing the second driver mesh includes: computing a plurality of triangular cells from the point set via Delaunay triangulation (Remacle §5, pg. 16 “We have then chosen to use a standard Delaunay kernel for connecting points because such a kernel is available in most mesh generators”: the triangular cells are computed from the inserted point set via Delaunay triangulation); and
combining the triangular cells into the second plurality of quadrilateral elements (Remacle §7, pg. 19 “The Delquad algorithm is an indirect algorithm. It first builds a triangular mesh, and a triangle merging procedure is subsequently used to generate quadrilaterals”: the triangular cells are combined into the quadrilateral elements of the resulting driver mesh, in the combination the second plurality of quadrilateral elements of the second driver mesh). In particular, Remacle teaches a surface quadrilateral mesh generator that inserts points over the surface with spacing prescribed by a mesh size field, connects the points into triangles with a standard Delaunay kernel, and merges the triangles into quadrilateral elements.
Musuvathy, Nguyen, De Lange, Marschall, and Remacle are analogous art because they are all reasonably pertinent to the problem faced by the inventor, generating a driver mesh of quadrilateral elements on the panel mid-surface whose element sizes follow a size field computed from the density field (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate Remacle into Musuvathy as modified by Nguyen, De Lange, and Marschall's invention for the purpose of Musuvathy's conformal template-lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142), to provide lattice cells sized such that the actual density of the lattice cell matches the local density derived from topology optimization (De Lange: [0032]), to provide a boundary conforming lattice cell design that avoids uniform, incompletely trimmed lattice structures in a laser-sintered sandwich panel (Marschall: §2.1, pg. 3), and to provide a quadrilateral driver mesh in which the points are placed in such a way that the triangle elements merge into quadrangles of optimal size and orientation (Remacle: §7, pg. 19).
8. Claims 8, 9 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Musuvathy in view of Nguyen, further in view of De Lange, further in view of Marschall, further in view of Geuzaine (“Gmsh: a three-dimensional finite element mesh generator with built-in pre- and post-processing facilities”).
Musuvathy as modified by Nguyen, De Lange, and Marschall teaches most all the instant invention as applied to claims 1-3, 6, 15-17 and 20 above.
As per Claim 8, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly smoothing the sandwich panel mesh in a direction locally orthogonal to a normal of the mid-surface CAD geometry.
Geuzaine teaches further comprising smoothing the sandwich panel mesh in a direction locally orthogonal to a normal of the mid-surface CAD geometry (Geuzaine §4.3, pg. 14 “Vertex Re-positioning: Each vertex is moved optimally inside the cavity made of all its surrounding triangles. The optimal position is chosen in order to maximize the worst element quality [10]”: the mesh is smoothed by optimally re-locating its vertices; Geuzaine §4.3, pg. 14 “the opportunity of doing a mesh modification is evaluated in the real space, i.e., in (x, y, z), while the validity of a mesh modification is evaluated in the parametric space (u, v)”: the vertex re-positioning is constrained to the surface's parametric space, so each vertex moves tangentially along the surface, that is, in a direction locally orthogonal to the surface normal, which in the combination is the normal of the mid-surface CAD geometry driving the sandwich panel mesh). In particular, Geuzaine teaches a surface-mesh optimization procedure that smooths the mesh by re-positioning vertices within the parametric space of the meshed surface, so that the smoothing displacement of each vertex is locally orthogonal to the surface normal.
Musuvathy, Nguyen, De Lange, Marschall, and Geuzaine are analogous art because they are all reasonably pertinent to the problem faced by the inventor, smoothing the sandwich panel mesh, including the panel infill mesh and the face sheet meshes, in a direction locally orthogonal to a normal of the panel mid-surface (In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of cited references. Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to incorporate Geuzaine into Musuvathy as modified by Nguyen, De Lange, and Marschall's invention for the purpose of Musuvathy's conformal template-lattice generation to provide a conformal hexahedral mesh in which one or more layers of cellular structure can be placed to support the part's skin (Nguyen: §2.1, pg. 142), to provide lattice cells sized such that the actual density of the lattice cell matches the local density derived from topology optimization (De Lange: [0032]), to provide a boundary conforming lattice cell design that avoids uniform, incompletely trimmed lattice structures in a laser-sintered sandwich panel (Marschall: §2.1, pg. 3), and to provide a mesh smoothing procedure that in practice converges in about 6-8 iterations and produces anisotropic meshes in the parametric space without computing derivatives of the mapping (Geuzaine: §4.3, pg. 14).
As per Claim 9, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein the sandwich panel mesh is smoothed over a plurality of smoothing iterations.
Geuzaine teaches wherein the sandwich panel mesh is smoothed over a plurality of smoothing iterations (Geuzaine §4.3, pg. 14: the local mesh modification algorithm, including its vertex re-positioning smoothing step, converges in about 6-8 iterations, a plurality of smoothing iterations).
As per Claim 18, Musuvathy as modified by Nguyen, De Lange, and Marschall fails to teach explicitly wherein generating the panel infill structure further includes smoothing the sandwich panel mesh in a direction locally orthogonal to a normal of the mid-surface CAD geometry.
Geuzaine teaches wherein generating the panel infill structure further includes smoothing the sandwich panel mesh in a direction locally orthogonal to a normal of the mid-surface CAD geometry (Geuzaine §4.3, pg. 14: as set out for claim 8, the sandwich panel mesh is smoothed by re-positioning vertices within the parametric space of the mid-surface, tangentially to the surface and locally orthogonal to its normal).
Examiner’s Note: This is a process limitation of the product claim; determination of patentability is based on the product itself (MPEP 2113), and the limitation is in any event fully addressed over the combination as set out above.
Conclusion
9. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Georges et al. (“Sandwich panels with functionally graded strut-based lattice cores”) teaches a sandwich panel with an optimization-graded strut-based lattice core symmetric about the midplane of the sandwich.
Remacle et al. (“Blossom-Quad: A non-uniform quadrilateral mesh generator using a minimum cost perfect matching algorithm”) teaches quadrilateral mesh generation by recombining the triangles of a triangular mesh as recited in claim 7.
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EUNHEE KIM
Primary Examiner
Art Unit 2188
/EUNHEE KIM/Primary Examiner, Art Unit 2188
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