Abstract
The unification of computer aided design (CAD) and the finite element method (FEM) has greatly enhanced the engineer's ability to evaluate potential designs (Finniganet al. 1989). However, analysis alone is not the answer to design, and thus shape optimization methods have become increasingly popular, particularly for structural problems (Yanget al. 1992; Botkin 1992). However, for shape optimization methods to be fully accepted by the engineering community they must first be integrated with CAD systems. To date, the difficulty of integrating CAD and shape optimization is the inability to relate the finite element nodal coordinates to the CAD solid model dimensions. Here, the critical link between these CAD and FEM data is developed within an industry standard feature-based modelling environment. A three-dimensional connecting rod model is optimized to exemplify the method.
Similar content being viewed by others
References
Aldefeld, B. 1988: Variation of geometries based on a geometric-reasoning method.Computer Aided Design 20, 117–126
Atiqullah, M.M.; Rao, S.S. 1995: Parallel processing in optimal structural design using simulated annealing.AIAA J. 33, 2386–2392
Belegundu, A.D.; Rajan, S.D. 1988: A shape optimization approach based on natural design variables and shape functions.Comp. Meth. Appl. Mech. Eng. 66, 87–106
Bendsøe, M.P. 1995:Optimization of structural topology, shape, and material. Berlin, Heidelberg, New York. Springer
Botkin, M.E. 1992: Three-dimensional shape optimization using fully automatic mesh generation.AIAA J. 30, 1932–1934
Braibant, V.; Fleury, C. 1984: Shape optimal design using bsplines.Comp. Meth. Appl. Mech. Eng. 44, 247–267
Chang, K.H.; Choi, K.K. 1992: A geometry-based parameterization method for shape design of elastic solids.Mech. Struct. & Mach. 20, 215–252
Chen, S. 1996:Three-dimensional shape optimization with variational geometry. Master's Thesis, University of Illinois at Urbana-Champaign
Chen, J.L.; Ho, J.S. 1994: A comparative study of design sensitivity analysis by using commercial finite element programs.Finite Elements in Analysis and Design 15, 189–200
Choi, K.K.; Twu, S.L. 1989: Equivalence of continuum and discrete methods of shape design sensitivity analysis.AIAA J. 27, 1418–1424
El-Sayed, M.E.M.; Zumwalt, K.W. 1991: Comparison of two different approaches for making design sensitivity analysis an integrated part of finite element analysis.Struct. Optim. 3, 149–156
Farin, G. 1988:Curves and surfaces for computer aided geometric design: a practical guide. New York: Academic Press
Fianigan, F.M.; Keia, A.; Davis, J.E., 1989: Geometry as a basis for finite element automation.Eng. with Comp. 5, 147–160
Foley, J.D.; van Dam, A.; Feiner, S.K.; Hughes, J.F. 1989:Computer graphics-principle and practice. Massachusetts: Addison-Wesley
Haftka, R.T.; Barthelemy, B. 1991: On the accuracy of shape sensitivity.Struct. Optim. 3, 1–6
Hoffmann, C.M. 1989:Geometric and solid modeling: an introduction. San Mateo, CA: Morgan Kaufmann
Kodiyalam, S.; Kumar, V.; Finnigan, P.M. 1992: Constructive solid geometry approach to three-dimensional structural shape optimization.AIAA J. 30, 1408–1415
Lee, K. 1983: Shape optimization of assemblies using geometric properties. Ph.D. Thesis, Massachusetts Institute of Technology
Lee, T.H.; Arora, J.S. 1993: Shape design sensitivity analysis of viscoplastic structures.Comp. Meth. Appl. Mech. Eng. 108, 237–259
Lee, K., Tortorelli, D.A. 1986: Computer-aided design of robotic manipulators.Computer Aided Design 18, 139–146
Light, R.A.; Gossard, D. 1982: Modification of geometric models through variational geometry.Computer Aided Design 14, 209–214
Light, R.A.; Gossard, D. 1983: Variational geometry: a new method for modifying part geometry for finite element analysis.Comp. & Struct. 17, 903–909
Lin, V.C.; Gossard, D.C.; Light, R.A. 1981: Variational geometry in computer-aided design.Computer Grafics 15, 171–177
Longo, A.; Unzueta, J.; Schaeidt, E.; Alvarez, A.; Anza, J.J. 1993: A general related variational approach to shape optimum design.Advances in Eng. Software 16, 135–142
Lund, E. 1994:Finite element based design sensitivity analysis and optimization. Ph.D. Thesis, Aalborg University
Marsan, A.L. 1995:Construction of a surface model from 3d homogenization output. Master's Thesis, University of Michigan
Mortenson, M.E. 1985:Geometric modeling. New York: John Willey & Sons
Olhoff, N.; Lund, E.; Rasmussen, J. 1992: Concurrent engineering design optimization in a CAD enviroment.Special Report 16, Institute of Mechanical Engineering, Aalborg University
Olhoff, N.; Rasmussen, J.; Lund, E. 1993: A method of “exact” numerical differentiation for error elimination in finite-element based semi-analytical shape sensitivity analyses.Mech. Struct. & Mach. 21, 1–66
Parametric Technology Corporation 1995a:Pro/Engineer users guide. Waltham, MA
Parametric Technology Corporation 1995b:Pro/Develop users guide. Waltham, MA
Pedersen, P.; Hammer, V.B. 1994: On global design description for orientational strength optimization.Report 481, Institute of Mechanical Engineering, Aalborg University
Pilkey, W.D.; Schramm, U. 1993: The coupling geometric descriptions and finite elements using nurbs—a study in shape optimization.Finite Elements in Analysis and Design 15, 11–34
Rajan, S.D. 1995: Sizing, shape, and topology design optimization of trusses using genetic algorithm,ASCE J. Struct. Eng. 121, 1480–1487
Rogers, D.F.; Adams, J.A. 1976:Mathematical elements for computer graphics. New York: McGraw-Hill
Shephard, M.S.; Georges, M.K. 1991: Automatic three-dimensional mesh generation by the finite octree technique.Int. J. Num. Meth. Eng. 32, 709–749
Spivey, C.O.; Tortorelli, D.A. 1994: Tangent operators, sensitivity expressions, and optimal design of non-linear elastica in contact with applications to beams.Int. J. Num. Meth. Engrg. 37, 49–73
Taylor, D.L. 1992:Computer-aided design. Massachusetts: Addison Wesley
The MacNeal-Schwendler Corporation 1994:MSC/NASTRAN users guide. Los Angeles
Tortorelli, D.A. 1993: A geometric representation scheme suitable for shape optimization.Mech. Struct. & Mach. 21, 95–121
Tortorelli, D.A.; Chen, S. 1996: Implementation of the semianalytical sensitivity method in commercial software for nonlinear problems. (Submitted)
Tortorelli, D.A.; Tomasko, J.A.; Morthland, T.E.; Dantzig, J.A. 1994. Optimal design of nonlinear parabolic systems — Part II: variable spatial domain with applications to casting optimization.Comp. Meth. Appl. Mech. Eng. 113, 157–172
Tortorelli, D.A.; Wang, Z. 1993: A systematic approach to shape sensitivity analysis.Int. J. Solids Struct. 30, 1181–1212
VMA Engineering 1991:Genesis user's manual. Goleta, CA
VMA Engineering 1993:Dot user's manual. Goleta, CA
Watt, A. 1993:3D computer graphics. Massachusetts: Addison-Wesley
Wolfram, S. 1991:Mathematica: a system for doing mathematics by computer. Massachusetts: Addison-Wesley
Yang, R.J.; Dewhirst, D.L.; Allison, J.E.; Lee, A. 1992: Shape optimization of connecting rod pin end using a generic model.Finite Elements in Analysis and Design 11, 257–264
Zhang, W.; Beckers, P.; Fleury, C. 1995: A unified parametric design approach to structural shape optimization.Int. J. Num. Meth. Eng. 38, 2283–2292
Author information
Authors and Affiliations
Additional information
Also: Department of Theoretical and Applied Mechanics
Rights and permissions
About this article
Cite this article
Chen, S., Torterelli, D.A. Three-dimensional shape optimization with variational geometry. Structural Optimization 13, 81–94 (1997). https://doi.org/10.1007/BF01199226
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01199226