# US 2021/0240887 A1 · Structural simulation of a mechanical part > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0240887 A1 - Document ID: US20210240887A1 - Status: Published application - Kind: A1 - Application number: 17/164,715 - Filed: 2021-02-01 - Published: 2021-08-05 - Earliest claimed: 2020-01-31 - Assignees: Dassault Systemes - Applicants: Dassault Systemes - Inventors: Yasmine Talha; David BENINCASA - Web page: https://patentgrep.com/patent/US20210240887A1 ## CPC - G06F 30/20: Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) - G06F 30/10: Geometric CAD - G06F 30/17: Mechanical parametric or variational design - G06F 30/23: using finite element methods [FEM] or finite difference methods [FDM] - G06F 2111/10: Numerical modelling - G06Q 10/101: Collaborative creation, e.g. joint development of products or services - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR ## Abstract A computer-implemented method of B-rep processing for performing structural simulation of a mechanical part including obtaining a first B-rep is described. The first B-rep forms a solid representing the mechanical part. The method further comprises providing a predetermined thickness threshold. The method further comprises constructing, based on the first B-rep, a second B-rep. The second B-rep forms a non-manifold object representing the mechanical part. The constructing comprises identifying one or more thin regions of the first B-rep. Each thin region has a thickness smaller than the predetermined thickness threshold. The constructing further comprises computing, for each identified thin region, a respective mid-surface of the identified thin region. The constructing further comprises replacing the identified thin region by the respective mid-surface. ## Claims ### Claim 1 A computer-implemented method of B-rep processing for performing structural simulation of a mechanical part, the method comprising: obtaining: a first B-rep forming a solid representing the mechanical part, and a predetermined thickness threshold; and constructing, based on the first B-rep, a second B-rep forming a non-manifold object representing the mechanical part, the constructing including: identifying one or more thin regions of the first B-rep, each thin region having a thickness smaller than the predetermined thickness threshold, and computing, for each identified thin region, a respective mid-surface of the identified thin region, and replacing the identified thin region by the respective mid-surface. ### Claim 2 (depends on 1) The method of claim 1, wherein the Identifying of the one or more thin regions comprises determining first and second groups each of one or more adjacent and tangent faces of the first B-rep, each first group being locally parallel to a respective second group and forming with the respective second group at least a part of a boundary of a thin region. ### Claim 3 (depends on 2) The method of claim 2, wherein the determining of the first and second groups includes: determining faces of the first B-rep each locally parallel to a respective other face, and grouping first determined adjacent and tangent faces locally parallel to second determined adjacent and tangent faces into first and second groups. ### Claim 4 (depends on 3) The method of claim 3, wherein the determining of the faces includes: determining candidate faces, a candidate face being a first face of the first B-rep for which a point is at a distance lower than the thickness threshold from a second face of the first B-rep, and determining, among candidate faces, first and second faces, each first face being locally parallel to a respective second face. ### Claim 5 (depends on 2) The method of claim 2, wherein two faces are locally parallel when: a ratio between a largest distance between the faces and a smallest distance between the faces is lower than one plus a threshold, and/or a ratio between a difference between a largest distance between the faces and a smallest distance between the faces and at least one diagonal length of the faces is lower than a tangent of a G1 continuity tolerance angle. ### Claim 6 (depends on 2) The method of claim 2, wherein the computing of a respective mid-surface for each identified thin region includes, for each determined first group locally parallel to a determined respective second group, computing, as a mid-surface, an intersection between a result of a first thickening operation of the first group and a result of an offset operation of the respective second group. ### Claim 7 (depends on 6) The method of claim 6, wherein: the offset operation is an offset of an extrapolation of the respective second group, and/or the first thickening operation has a thickening distance larger than the thickness threshold. ### Claim 8 (depends on 2) The method of claim 2, wherein the constructing further Includes computing one or more local thick regions of the first B-rep, the computing of the one or more local thick regions including: for each determined first group locally parallel to a determined respective second group, computing an intersection of a result of a second thickening operation of the first group and a result of a third thickening operation of the respective second group, and subtracting from the first B-rep each computed Intersection. ### Claim 9 (depends on 8) The method of claim 8, wherein: the second thickening operation of the first group is a thickening of an extrapolation of the first group, and the third thickening operation of the respective second group is a thickening of an extrapolation of the respective second group, the extrapolation of the first group and the extrapolation of the respective second group having different extrapolation values, and/or the third thickening operation and the second thickening operation have each a thickening distance larger than the thickness threshold. ### Claim 10 (depends on 8) The method of claim 8, wherein the replacing Including assembling the respective mid-surface with a respective computed thick region by assembling a boundary edge of the respective mid-surface with a splitting edge of the respective computed thick region. ### Claim 11 (depends on 1) The method of claim 1, further comprising meshing the second B-rep into a hybrid mesh. ### Claim 12 (depends on 11) The method of claim 11, further comprising performing a structural simulation of the mechanical part based on the hybrid mesh. ### Claim 13 A non-transitory computer readable storage medium having recorded thereon a computer program comprising instructions for performing a method of B-rep processing for performing structural simulation of a mechanical part, the method comprising: obtaining: a first B-rep forming a solid representing the mechanical part, and a predetermined thickness threshold; and constructing, based on the first B-rep, a second B-rep forming a non-manifold object representing the mechanical part, the constructing including: identifying one or more thin regions of the first B-rep, each thin region having a thickness smaller than the predetermined thickness threshold, and computing, for each identified thin region, a respective mid-surface of the identified thin region, and replacing the Identified thin region by the respective mid-surface. ### Claim 14 (depends on 13) The non-transitory computer readable storage medium of claim 13, wherein the identifying of the one or more thin regions Includes determining first and second groups each of one or more adjacent and tangent faces of the first B-rep, each first group being locally parallel to a respective second group and forming with the respective second group at least a part of a boundary of a thin region. ### Claim 15 (depends on 14) The non-transitory computer readable storage medium of claim 14, wherein the determining of the first and second groups includes: determining faces of the first B-rep each locally parallel to a respective other face, and grouping first determined adjacent and tangent faces locally parallel to second determined adjacent and tangent faces into first and second groups. ### Claim 16 (depends on 15) The non-transitory computer readable storage medium of claim 15, wherein the determining of the faces includes: determining candidate faces, a candidate face being a first face of the first B-rep for which a point is at a distance lower than the thickness threshold from a second face of the first B-rep, and determining, among candidate faces, first and second faces, each first face being locally parallel to a respective second face. ### Claim 17 A computer comprising: a processor coupled to a memory and a graphical user-interface, the memory having recorded thereon a computer program comprising Instructions for performing structural simulation of a mechanical part that when executed by the processor causes the processor to be configured to: obtain: a first B-rep forming a solid representing the mechanical part, and a predetermined thickness threshold; and construct, based on the first B-rep, a second B-rep forming a non-manifold object representing the mechanical part, wherein the processor is further configured to construct the second B-rep by being configured to: identify one or more thin regions of the first B-rep, each thin region having a thickness smaller than the predetermined thickness threshold, and compute, for each identified thin region, a respective mid-surface of the identified thin region, and replacing the identified thin region by the respective mid-surface. ### Claim 18 (depends on 17) The computer of claim 17, wherein the processor is further configured to Identify the one or more thin regions by being configured to determine first and second groups each of one or more adjacent and tangent faces of the first B-rep, each first group being locally parallel to a respective second group and forming with the respective second group at least a part of a boundary of a thin region. ### Claim 19 (depends on 18) The computer of claim 18, wherein the processor is further configured to determine the first and second groups by being configured to: determine faces of the first B-rep each locally parallel to a respective other face, and group first determined adjacent and tangent faces locally parallel to second determined adjacent and tangent faces into first and second groups. ### Claim 20 (depends on 19) The computer of claim 19, wherein the processor is further configured to determine the faces by being configured to: determine candidate faces, a candidate face being a first face of the first B-rep for which a point is at a distance lower than the thickness threshold from a second face of the first B-rep, and determine, among candidate faces, first and second faces, each first face being locally parallel to a respective second face.