Iranian Journal of  Manufacturing Engineering

Iranian Journal of Manufacturing Engineering

Topology optimization of continuous structures using a combination of Galerkin mesh-free methods and bidirectional evolutionary topology optimization

Document Type : Original Article

Authors
Department of Civil Engineering, Babol Noshirvani University of Technology, Babol, Iran
10.22034/ijme.2025.531262.2107
Abstract
This paper presents an advanced approach to optimize the topology of structures by combining the bidirectional evolutionary structural optimization method with the mesh-free Galerkin method. The main goal of this hybrid approach is to significantly reduce the computational time while maintaining high accuracy in the optimization process. Traditional mesh-based methods, especially in problems involving complex geometries, often require accurate mesh generation and repeated mesh reconstruction during the optimization process, which can significantly increase the computational cost and complexity. Therefore, by combining a mesh-free method such as the mesh-free Galerkin method, the proposed approach eliminates the need for mesh generation and, when combined with the efficiency of the bidirectional evolutionary topology optimization algorithm, leads to a faster and simpler optimization process. The numerical results presented in this study show that this hybrid method is up to 2.5 times faster than conventional finite element-based approaches, while still ensuring reliable mechanical performance and structural integrity. Furthermore, due to the flexibility of the Galerkin mesh-free method in handling complex geometries and variable boundary conditions, the proposed technique is particularly effective for real-world engineering applications. It is particularly suitable for industries such as aerospace, automotive, and mechanical engineering where the demand for lightweight, robust, and complex structural designs is high. Overall, the integration of the Galerkin mesh-free method and bidirectional evolutionary optimization provides a robust and efficient solution to the limitations of traditional topology optimization techniques.

Numerical results presented in this study show that this combined method is up to 2.5 times faster than conventional approaches based on the finite element method (FEM), while still ensuring reliable mechanical performance and structural integrity. Furthermore, due to the flexibility of the EFG method in handling complex geometries and variable boundary conditions, the proposed technique is particularly effective for real-world engineering applications. This method is particularly suitable for industries such as aerospace, automotive, and mechanical engineering where the demand for lightweight, strong, and complex structural designs is high. Overall, the integration of BESO and EFG provides a robust and efficient solution to the limitations of traditional topology optimization techniques.
Keywords

[1] Michell AG. LVIII. The limits of economy of material in frame-structures. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. 1904 Nov 1;8(47):589-97. doi: 10.1080/14786440409463229
[2] Bendsøe MP, Kikuchi N. Generating optimal topologies in structural design using a homogenization method. Computer methods in applied mechanics and engineering. 1988 Nov 1;71(2):197-224. doi: 10.1016/0045-7825(88)90086-2
[3] Bendsoe MP, Sigmund O. Topology optimization: theory, methods, and applications. Springer Science & Business Media; 2013 Apr 17. doi: 10.1007/978-3-662-05086-6
[4] Xie YM, Steven GP. A simple evolutionary procedure for structural optimization. Computers & structures. 1993 Dec 3;49(5):885-96. doi: 10.1016/0045-7949(93)90035-C
[5] Huang X, Xie M. Evolutionary topology optimization of continuum structures: methods and applications. John Wiley & Sons; 2010 Mar 11. doi: 10.1002/9780470689486
[6] Sigmund O, Maute K. Topology optimization approaches: A comparative review. Structural and multidisciplinary optimization. 2013 Dec;48(6):1031-55. doi: 10.1007/s00158-013-0978-6
[7] Li W, Cui M, Wang X, Gao M. An enhanced proportional topology optimization method with new density filtering weight function for the minimum compliance problem. Mechanics Based Design of Structures and Machines. 2025 Apr 3;53(4):2666-95. doi: 10.1080/15397734.2024.2412753
[8] Sigmund O, Petersson J. Numerical instabilities in topology optimization: a survey on procedures dealing with checkerboards, mesh-dependencies and local minima. Structural optimization. 1998 Aug;16(1):68-75. doi: 10.1007/BF01214002
[9] Bourdin B. Filters in topology optimization. International journal for numerical methods in engineering. 2001 Mar 30;50(9):2143-58. doi: 10.1002/nme.116
[10] Alinaghi K, Golabi SI. Minimizing piston mass of Neuman Esser reciprocating compressors using genetic algorithm. Iranian Journal of Manufacturing Engineering. 2021 Jul 23;8(5):30-42.
[11] Lavaei A, Firoozjaee AR. Topology optimization of continuum structures using element free Galerkin method on irregular nodal distribution. International Journal of Mechanics and Materials in Design. 2021 Jun;17(2):333-44. doi: 10.1007/s10999-020-09528-4
[12] Zhao L, Zheng J, Cai J, Hu J, Han Y, Rong J. Stress-constrained topology optimization of geometrically nonlinear continuum structures by using parallel computing strategy. Advances in Engineering Software. 2025 Jan 1;199:103805. doi: 10.1016/j.advengsoft.2024.103805
[13] Rafiee R, Amohaji H. Experimental study and predicting the tensile strength of nanocomposite specimens produced with a 3D printer. Iranian Journal of Manufacturing Engineering. 2025 May 22;12(3):1-9. doi: 10.22034/ijme.2025.511057.2056
[14] Jia Y, Liu K, Zhang XS. Topology optimization of irregular multiscale structures with tunable responses using a virtual growth rule. Computer Methods in Applied Mechanics and Engineering. 2024 May 15;425:116864. doi: 10.1016/j.cma.2024.116864
[15] Elvas A, Sohouli A, Suleman AJ. Simultaneous topology and fiber path optimization of composite structures with MAC constraints. Composite Structures. 2022 Aug 15;294:115645. doi: 10.1016/j.compstruct.2022.115645
[16] Mojiri S, Shafiei AR. Topology Optimization Of Structures With Thermal And Mechanical Loading. Iranian Journal of Manufacturing Engineering. 2021 Feb 19;7(12):54-63.
[17] Sefidgar SM, Firoozjaee AR, Dehestani M. Sparse discrete least squares meshless method on multicore computers. Journal of Computational Science. 2022 Jul 1;62:101686. doi: 10.1016/j.jocs.2022.101686
[18] Abdi M, Ashcroft I, Wildman R. An X-FEM based approach for topology optimization of continuum structures. InSimulation and Modeling Methodologies, Technologies and Applications: International Conference, SIMULTECH 2012 Rome, Italy, July 28-31, 2012 Revised Selected Papers 2014 (pp. 277-289). Cham: Springer International Publishing. doi: 10.1007/978-3-319-03581-9_20
[19] He Q, Kang Z, Wang Y. A topology optimization method for geometrically nonlinear structures with meshless analysis and independent density field interpolation. Computational Mechanics. 2014 Sep;54(3):629-44. doi: 10.1007/s00466-014-1011-7
[20] Zhao F. Topology optimization with meshless density variable approximations and BESO method. Computer-Aided Design. 2014 Nov 1;56:1-0. doi: 10.1016/j.cad.2014.06.003
[21] Firoozjaee AR, Sahebdel M. Element-free Galerkin method for numerical simulation of sediment transport equations on regular and irregular distribution of nodes. Engineering Analysis with Boundary Elements. 2017 Nov 1;84:108-16. doi: 10.1016/j.enganabound.2017.08.007
[22] Allaire G, Jouve F, Toader AM. Structural optimization using sensitivity analysis and a level-set method. Journal of computational physics. 2004 Feb 10;194(1):363-93. doi: 10.1016/j.jcp.2003.09.032
[23] Liu GR, Gu YT. An introduction to meshfree methods and their programming. Dordrecht: Springer Netherlands; 2005 Jul.
[24] Kambampati S, Chung H, Kim HA. A discrete adjoint based level set topology optimization method for stress constraints. Computer Methods in Applied Mechanics and Engineering. 2021 Apr 15;377:113563. doi: 10.1016/j.cma.2020.113563
[25] Wu C, Fang J, Zhou S, Zhang Z, Sun G, Steven GP, Li Q. A path-dependent level set topology optimization with fracture criterion. Computers & Structures. 2021 Jun 1;249:106515. doi: 10.1016/j.compstruc.2021.106515
[26] Gharibi K, Tamijani AY. Load-path-based topology optimization of two-dimensional continuum structures. AIAA Journal. 2021 Sep;59(9):3725-34. doi: 10.2514/1.J059642
[27] Panesar A, Brackett D, Ashcroft I, Wildman R, Hague R. Hierarchical remeshing strategies with mesh mapping for topology optimisation. International Journal for Numerical Methods in Engineering. 2017 Aug 17;111(7):676-700. doi: 10.1002/nme.5488
[28] Luo Z, Zhang N, Wang Y, Gao W. Topology optimization of structures using meshless density variable approximants. International Journal for Numerical Methods in Engineering. 2013 Jan 27;93(4):443-64. doi: 10.1002/nme.4394
[29] Huang X, Xie YM. A further review of ESO type methods for topology optimization. Structural and Multidisciplinary Optimization. 2010 May;41(5):671-83. doi: 10.1007/s00158-010-0487-9