14Notice 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
1. Claims 1-11 are presented for examination.
Claim Objections
2. Claims 1 and 7 are objected to because of the following informalities:
As per Claim 1 and 7, they recite the limitation “course mesh” in the body while the preamble recites “coarse-mesh”. The “course” appears to be a typographical error.
As per Claim 1, and 7, they recite the limitation “virtual nodes” which is unclear what the limitation refers. According to Fig. 3, those are not normal nodes of the mesh. Clarfication is respectfully requested.
As per Claim 1 and 7, they recite the limitation “the analytically derived stiffness matrix” which is unclear what the limitation refers. Is it referring to the “analytically” reduced the “combined stiffness matrix” previously claimed?
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 1-11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
As per Claim 1, it recites the limitation “imposing final membrane stiffness matrix expressed in closed form” in line 9 which is unclear what the limitation refers. In particular, it is unclear the meets and bounds of “final”. What qualifies a stiffness matrix as “final”?
As per Claim 1 and 7, they recite the limitation “analytically reducing a combined stiffness matrix” which is unclear what the limitation refers since “combined” was not determined in a prior step therefore to reducing has no nexus. In particular, it is unclear what is a “combined” stiffness matrix, and how it relates to the limitation previously claimed “imposed final membrane stiffness matrix”. It appears necessary that a bending stiffness matrix is combined with the membrane stuffiness matrix; if so, “combined” was not determined in a prior step.
As per Claim 1 and 7, they recite the limitation “outputting structural stresses….” which is unclear what the limitation refers since “structural stresses” was not determined in a prior step therefore to outputting has no nexus. In particular, none of the previous step performs computing quantities of “structural stress”.
As per Claim 8, it recites the limitation “the spot-joined structure” in line 2. There is insufficient antecedent basis for this limitation in the claim.
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.
4. Claims 1-6 are rejected under 35 U.S.C. 103 as being unpatentable over Andersson (“Fatigue Life and Stiffness of the Spider Spot Weld Model”) in view of Kang (“Fatigue analysis of spot welds using a mesh-insensitive structural stress approach”), further in view of Salvini (“A spot weld finite element for structural modelling”).
As per Claim 1, Andersson teaches a method for enabling coarse-mesh/high-fidelity Computer-Aided Engineering (CAE) durability evaluation of spot-joined structures (Title, pg. 6, §3.2.1 “The calculated radial stresses are used to assess the fatigue life of the spot welded joints.”: coarse-mesh finite-element spot-weld models evaluated in a CAE environment for fatigue-life assessment of spot-welded joints), the method comprising:
providing a course mesh joint representation of the spot-joined structure (pg. 6, §3.2.2 “The model consists of an eight node solid element which represents the nugget, (CHEXA in Nastran), connected to the surrounding mesh by kinematic coupling constraints (RBE3 in Nastran)”: the ACM2 nugget element embedded in the surrounding shell mesh is a coarse-mesh representation of the spot joint);
imposing spot joint constraints at virtual nodes of the course mesh joint representation (pg. 6-7, §3.2.2 “These interpolation constraints are expressed using the shape functions of the shell elements and the displacement of the connected nodes”; §3.2.3 “A rigid area equal to the size of the spot weld is created by rigid elements (RBE2 in Nastran) in a spoke pattern in each steel sheet.”: the kinematic coupling and rigid-spoke constraints imposed at the connection nodes around the nugget are spot joint constraints imposed at virtual nodes of the coarse-mesh representation); and
outputting structural stresses around a joint for durability or fatigue life prediction purposes (pg. 6, §3.2.1 “For fatigue analyses forces and moments in the beam element are extracted. Radial stresses in the adjoining sheets are calculated according to an analytical expression”; §3.2.2 “The command MPCFORCE in Nastran outputs the forces and moments in a global coordinate system at the corner nodes of the CHEXA element.”: the radial stresses computed around the weld from the extracted nodal forces and moments are output to assess the fatigue life of the joint).
In particular, Andersson teaches coarse-mesh finite-element spot-weld models in which a solid nugget element is connected to the surrounding shell mesh by kinematic constraints at connection nodes, and the forces and moments extracted at those nodes are converted into stresses that are used to assess the fatigue life of the spot-welded joints.
However, Andersson fails to teach explicitly imposing membrane deformation joint constraints on the course mesh joint representation; imposing final membrane stiffness matrix expressed in closed form; imposing bending deformation joint constraints on the course mesh joint representation; analytically reducing a combined stiffness matrix of 36x36 to a UEL element stiffness matrix of 24x24; and coding in computer programming language the analytically derived stiffness matrix (24x24) into a UEL subroutine for interfacing with CAE code.
Kang teaches imposing membrane deformation joint constraints on the course mesh joint representation (pg. 1549-1550, §2.2 “The balanced nodal forces and moments in a global coordinate system at each mesh corner along the weld line (nugget periphery) with respect to the shaded elements in Fig. 3 are directly obtained from a linear elastic finite element analysis.”,
“
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”: the membrane component imposed in an equilibrium sense on the nodal forces at the nugget periphery of the coarse-mesh model is a membrane deformation joint constraint as claimed); and
imposing bending deformation joint constraints on the course mesh joint representation (pg. 1548, §2 “
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”: the bending component imposed on the nodal forces and moments at the same nugget periphery is a bending deformation joint constraint as claimed).
In particular, Kang teaches the application of a nodal-force-based, mesh-insensitive structural stress parameter to spot welds, in which equilibrium-equivalent membrane and bending components are computed from the nodal forces and moments at each nodal point along the periphery of the weld nugget of a coarse finite-element model.
Andersson and Kang are analogous art because they are both from the same field of endeavor, finite-element fatigue evaluation of spot-welded structures.
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 Kang into Andersson’s invention to provide a mesh-insensitive structural stress measure that can be readily/successfully applied to coarse spot-weld models for fatigue life prediction (Kang: pg. 1553, §4).
However, Andersson in view of Kang fails to teach explicitly imposing final membrane stiffness matrix expressed in closed form; analytically reducing a combined stiffness matrix of 36x36 to a UEL element stiffness matrix of 24x24; and coding in computer programming language the analytically derived stiffness matrix (24x24) into a UEL subroutine for interfacing with CAE code.
On the other hand, Salvini teaches imposing final membrane stiffness matrix expressed in closed form (pg. 646, §2 “The stiffness of the in-plane beams (to get the solution it will be necessary to account for beams with rigid offset) are selected so as to present a global stiffness behaviour equal to the bidimensional case solved in closed form.”; pg. 652, §3 “The stiffness is defined through the ratio between the loads acting on the surrounding nodes and the displacement enforced to the central node.”: the in-plane, i.e. membrane, stiffness of the spot-joint element is expressed in closed analytical form);
analytically reducing a combined stiffness matrix of 36x36 to a UEL element stiffness matrix of 24x24 (pg. 654, §3 “a method to uncouple all the beams through the release of some degrees of freedom does exist”: the analytic element formation releases internal degrees of freedom so that the assembled stiffness is expressed in terms of the retained boundary-node displacements; for a four-node connection with six degrees of freedom per node the retained element matrix is 24x24, i.e., the claimed reduction of the combined 36x36 matrix to a 24x24 UEL element stiffness matrix); and
coding in computer programming language the analytically derived stiffness matrix (24x24) into a UEL subroutine for interfacing with CAE code (pg. 654, §3 “the use of monodimensional elements instead of built-in elements, through direct definition of element stiffness matrix, allows the introduction of this spot weld element in any structural finite element code”; Examiner’s Note – the claimed “UEL subroutine for interfacing with CAE code” corresponds to Salvini’s introduction of the analytically derived element stiffness matrix into a structural finite element code through direct, user-side definition of the element stiffness matrix).
In particular, Salvini teaches a spot weld finite element whose stiffness is derived from closed-form analytic solutions of the region surrounding the spot weld, assembled with released internal degrees of freedom, and introduced through direct definition of the element stiffness matrix into any structural finite element code.
Andersson, Kang, and Salvini are analogous art because they are all from the same field of endeavor, finite-element modelling of spot welds for structural and fatigue analysis.
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 Salvini into Andersson as modified by Kang’s invention to provide the accuracy of an analytic spot-weld solution without mesh refinement and without an increase of the numerical model heaviness (Salvini: pg. 645, §1; pg. 655, §5).
As per Claim 2, Andersson fails to teach explicitly further comprising determining whether the spot-joined structure meets required durability or fatigue life criteria and manufacturing the spot joined structure.
Kang teaches further comprising determining whether the spot-joined structure meets required durability or fatigue life criteria and manufacturing the spot joined structure (pg. 1546, §1 “Spot welding is a widely employed technique to join sheet steels for body and cap structure in the automotive industry.”; pg. 1553, §4 “a relatively good correlation of the fatigue data collected from various advanced high strength sheet steel tested under tensile-shear and coach-peel loadings has been established for fatigue life prediction purposes”: the established fatigue-life correlation is applied to determine whether spot-welded vehicle structures meet fatigue-life requirements, and the spot-welded sheet-steel body structures so evaluated are manufactured in the automotive industry).
As per Claim 3, Andersson fails to teach explicitly wherein the spot joint constraints include the relationships Node 1: (x1,y1)=(0,a); Node 2: (x2,y2)=(√2a/2, √2a/2); Node 3: (x3,y3)=(b,b); Node 4: (x4,y4)=(0,b), where a=the joint weld nugget radius and b=element size.
Salvini teaches wherein the spot joint constraints include the relationships Node 1: (x1,y1)=(0,a); Node 2: (x2,y2)=(√2a/2, √2a/2); Node 3: (x3,y3)=(b,b); Node 4: (x4,y4)=(0,b), where a=the joint weld nugget radius and b=element size (pg. 646, Fig. 3, §2 “a spot welded junction, connecting two metal sheets, is formed by two sets of radial beams lying on each sheet”; pg. 652, Fig. 6, §3 “
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”: the spot-joint element is geometrically parameterized by the nugget radius and by constraint nodes positioned on the surrounding shell mesh; fixing the constraint nodes at the recited coordinates expressed in the nugget radius a and the element size b is the routine geometric definition of a coarse-mesh element circumscribing the nugget).
As per Claim 4, Andersson teaches wherein the membrane deformation joint constraints include rigid kinematic relationships (pg. 7, §3.2.3 “A rigid area equal to the size of the spot weld is created by rigid elements (RBE2 in Nastran) in a spoke pattern in each steel sheet. The rigid elements are oriented from the centre of the nugget to the weld line.”: the rigid spoke elements impose rigid kinematic relationships among the constrained nodes of the in-plane joint connection).
As per Claim 5, Andersson fails to teach explicitly wherein the membrane deformation joint constraints include force equilibrium equations.
Kang teaches wherein the membrane deformation joint constraints include force equilibrium equations (pg. 1549-1550, §2.2 “The nodal forces and moments in the local coordinate system are then converted to the distributed forces in terms of line forces and moments using the assumption that the work done by the nodal forces is equal to the work done by the distributed forces.”: the membrane component is imposed through equilibrium and work-equivalence equations on the nodal forces of the joint model).
As per Claim 6, Andersson fails to teach explicitly wherein the force equilibrium equations include Fx7=Fx1+Fx2+Fx5; and Fy7=Fy1+Fy2+Fy5.
Kang teaches wherein the force equilibrium equations include Fx7=Fx1+Fx2+Fx5; and Fy7=Fy1+Fy2+Fy5 (pg. 1549-1550, §2.2: the recited x-direction and y-direction nodal-force summations are the equilibrium relations among the nodal force components of the joint element that Kang’s balanced-nodal-force formulation and work-equivalence equations express).
5. Claims 7 and 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Andhale (“Mesh Insensitive Structural Stress Approach for Welded Components Modeled using Shell Mesh”) in view of Salvini (“A spot weld finite element for structural modelling”).
As per Claim 7, Andhale teaches a method for enabling coarse-mesh/high-fidelity Computer-Aided Engineering (CAE) durability evaluation of seam-joined structures (Title, Abstract), the method comprising:
providing a course mesh joint representation of the seam-joined structure (pg. 1432, §V.A “QUAD4 elements are to be used in case of shell mesh and hence shape function of these QUAD4 elements is used to calculate line forces.”: the welded component, including the weld toe region, is represented by a shell mesh of QUAD4 elements);
imposing seam joint membrane constraints at virtual nodes of the course mesh joint representation (pg. 1429, Fig. 8, §III.B “the balanced nodal forces and moments within each element automatically satisfy the equilibrium conditions at every nodal position. Therefore, the equilibrium-equivalent structural stress state in the form of membrane and bending can be calculated by using the nodal forces/moments at a location of concern.”: the membrane component of the equilibrium-equivalent structural stress state imposed at the nodal positions along the weld line is a seam joint membrane constraint imposed at virtual nodes);
imposing seam weld joint constraints on the course meh joint representation (pg. 1429, §III.C “In order to calculate the structural stresses in terms of membrane and bending components, line forces and moments must be properly formulated by introducing work-equivalent arguments”, “for a closed weld line, the nodal forces can be related to line forces along an arbitrarily curved weld”: the work-equivalent line-force and line-moment relations imposed along the weld line are seam weld joint constraints imposed on the coarse-mesh representation); and
outputting structural stresses around a seam joint for durability or fatigue life prediction purposes (pg. 1430, §III.C
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”; pg. 1434,fig. 20-21, Table XI: the membrane-plus-bending structural stress along the weld is output and used for fatigue-life calculation of the welded component).
In particular, Andhale teaches the mesh-insensitive structural stress method applied on shell meshes of welded components, in which balanced nodal forces and moments along the weld line are converted by work-equivalent equations into line forces and moments and into membrane and bending structural stress components that are used for fatigue life calculations.
However, Andhale fails to teach explicitly imposing shell element stiffness matrix expressed in closed form; analytically reducing a combined stiffness matrix of 36x36 to a UEL element stiffness matrix of 24x24; and coding in computer programming language the analytically derived stiffness matrix (24x24) into a UEL subroutine for interfacing with CAE code.
Salvini teaches imposing shell element stiffness matrix expressed in closed form (pg. 646, §2 “The stiffness of the in-plane beams (to get the solution it will be necessary to account for beams with rigid offset) are selected so as to present a global stiffness behaviour equal to the bidimensional case solved in closed form.”; pg. 652, §3 “The stiffness is defined through the ratio between the loads acting on the surrounding nodes and the displacement enforced to the central node.”: the in-plane, i.e. membrane, stiffness of the spot-joint element is expressed in closed analytical form and the joint-region element stiffness, derived from closed-form analytic plate solutions, is a shell element stiffness matrix expressed in closed form);
analytically reducing a combined stiffness matrix of 36x36 to a UEL element stiffness matrix of 24x24 (pg. 654, §3 “a method to uncouple all the beams through the release of some degrees of freedom does exist”: the analytic element formation releases internal degrees of freedom so that the assembled stiffness is expressed in terms of the retained boundary-node displacements; for a four-node connection with six degrees of freedom per node the retained element matrix is 24x24, i.e., the claimed reduction of the combined 36x36 matrix to a 24x24 UEL element stiffness matrix); and
coding in computer programming language the analytically derived stiffness matrix (24x24) into a UEL subroutine for interfacing with CAE code (pg. 654, §3 “the use of monodimensional elements instead of built-in elements, through direct definition of element stiffness matrix, allows the introduction of this spot weld element in any structural finite element code”; Examiner’s Note – the claimed “UEL subroutine” corresponds to Salvini’s direct, user-side definition of the element stiffness matrix introduced into any structural finite element code).
In particular, Salvini teaches the closed-form analytic derivation of the stiffness of the region surrounding a weld and its implementation by direct definition of the element stiffness matrix in a structural finite element code.
Andhale and Salvini are analogous art because they are both from the same field of endeavor, finite-element structural modelling of welded joints for fatigue evaluation.
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 Salvini into Andhale’s invention to provide the accuracy of an analytic joint-region solution without mesh refinement and without an increase of the numerical model heaviness (Salvini: pg. 645, §1; pg. 655, §5).
As per Claim 9, Andhale fails to teach explicitly wherein the seam joint membrane constraints include rigid kinematic relationships.
Salvini teaches wherein the seam joint membrane constraints include rigid kinematic relationships (pg. 646, Fig. 2, §2 “a spot welded junction, connecting two metal sheets, is formed by two sets of radial beams lying on each sheet, and by a link (it can be rigid or not), perpendicular to the sheets, which connects the two sets”: the rigid link and the rigid-offset members impose rigid kinematic relationships among the constrained in-plane degrees of freedom of the joint).
As per Claim 10, Andhale teaches wherein the seam joint membrane constraints include force/moment equilibrium equations (pg. 1429, §III.B “the balanced nodal forces and moments within each element automatically satisfy the equilibrium conditions at every nodal position. Therefore, the equilibrium-equivalent structural stress state in the form of membrane and bending can be calculated by using the nodal forces/moments at a location of concern.”’ §III.C: the balanced nodal force and moment equilibrium conditions and the work-equivalent line-force and line-moment equations are force/moment equilibrium equations imposed on the joint).
As per Claim 11, Andhale fails to teach explicitly where the seam weld joint constraints include rigid inclusion constraints.
Salvini teaches where the seam weld joint constraints include rigid inclusion constraints (pg. 646, §2 “the spot nugget (having a rigid core) is loaded in the three possible typologies”: the rigid core at the weld nugget is a rigid inclusion imposing rigid inclusion constraints on the joint model).
6. Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Andhale (“Mesh Insensitive Structural Stress Approach for Welded Components Modeled using Shell Mesh”) in view of Salvini (“A spot weld finite element for structural modelling”), and further in view of Kang (“Fatigue analysis of spot welds using a mesh-insensitive structural stress approach”).
Andhale as modified by Salvini teaches most all the instant invention as applied to claims 7 and 9-11 above.
As per Claim 8, Andhale as modified by Salvini fails to teach explicitly further comprising determining whether the spot-joined structure meets required durability or fatigue life criteria and manufacturing the spot joined structure.
Kang teaches further comprising determining whether the spot-joined structure meets required durability or fatigue life criteria and manufacturing the spot joined structure (pg. 1546, §1 “Spot welding is a widely employed technique to join sheet steels for body and cap structure in the automotive industry.”; pg. 1553, §4 “a relatively good correlation of the fatigue data collected from various advanced high strength sheet steel tested under tensile-shear and coach-peel loadings has been established for fatigue life prediction purposes”: the established fatigue-life correlation is applied to determine whether spot-welded vehicle structures meet fatigue-life requirements, and the spot-welded sheet-steel body structures so evaluated are manufactured in the automotive industry).
Andhale, Salvini, and Kang are analogous art because they are all from the same field of endeavor, finite-element fatigue evaluation of welded structures.
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 Kang into Andhale as modified by Salvini’s invention to provide the accuracy of an analytic joint-region solution without mesh refinement and without an increase of the numerical model heaviness (Salvini: pg. 645, §1; pg. 655, §5) and to provide an established fatigue-data correlation usable for fatigue life prediction of the welded structure (Kang: pg. 1553, §4).
Conclusion
5. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Dong (US 6,901,809 B2) teaches calculating structural stress in a fatigue-prone weld region of a finite element model from nodal displacements and nodal force and moment vectors.
Dong (US 7,089,124 B2) teaches structural stress analysis of welded structures using balanced nodal forces and moments substantially independent of mesh size.
Dong (US 7,516,673 B2) teaches structural stress determination for weld fatigue evaluation using nodal force and displacement values from finite element solutions.
Nutwell (US 7,640,146 B2) teaches modeling spot welds in a finite element analysis in which the spot welds are represented by beam elements or clusters of solid elements connected to the surrounding mesh.
Hallquist (US 7,945,432 B2) teaches spot weld failure determination in a finite element analysis using force and moment resultants computed at the spot welds of a structure.
7. Any inquiry concerning this communication or earlier communications from the examiner should be directed to EUNHEE KIM whose telephone number is (571)272-2164. The examiner can normally be reached Monday-Friday 9am-5pm ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Ryan Pitaro can be reached at (571)272-4071. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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EUNHEE KIM
Primary Examiner
Art Unit 2188
/EUNHEE KIM/Primary Examiner, Art Unit 2188
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