Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
An implementation of the TOBS method for topology optimization of large-scale 3D structures
Submission Author:
Lucas Mamedes , DF
Co-Authors:
Lucas Mamedes, Renato Picelli, Josue Labaki
Presenter: Lucas Mamedes
doi://10.26678/ABCM.COBEM2023.COB2023-2372
Abstract
This paper presents an implementation of the Topology Optimization of Binary Structures (TOBS) method for the design of large-scale, 3D structures. TOBS is a well-established method of topology optimization, and in this paper we show that it is adequate for designing large-scale structures as well. TOBS’ binary-density formulation makes it more suitable to address the design of large-scale buildings than continuous-density variation methods, because intermediate densities yield unfeasible designs for engineering practice, and are known for resulting in numerical instability in some cases, among other difficulties. Unlike its more popular counterpart Binary Evolutionary Structural Optimization (BESO) method, TOBS is not limited by the shortcoming of being almost entirely constrained to volume restriction problems. Although this is often the case in engineering objects, volume may be of secondary importance in the design of large-scale buildings. TOBS enables an exploration of topological design under different types of restrictions. TOBS also uses binary design variables, which is one of the advantages of BESO, but it generalizes the optimization problem by using sequential linear approximations and an integer programming solver, which allows any type of continuously differentiable objective function and constraints to be incorporated. The implementation consists of a finite element solver that uses classical, hexahedral, linear-elastic finite elements with eight nodes with three degrees of freedom per node. Material interpolation is implemented according to the classical Solid Isotropic Material with Penalisation (SIMP) method. Elemental and nodal sensitivity and filtering schemes are implemented according to an extension of the classical BESO to three dimensions. TOBS’ integer linear programming algorithm has shown to be able to navigate the added complexity of the 3D problems with no difficulty. The paper proposes strategies to deal with the added computational cost resulting from larger-scale problems. The results show selected applications of the model to the design of large-scale 3D problems, which include a high rise building and a multi-lane bridge.
Keywords
Topology optimization, TOBS, 3D
