Lightweight design of bus frames from multi-material topology optimization to cross-sectional size optimization

ABSTRACT

A comprehensive solution for bus frame design is proposed to bridge multi-material topology optimization and cross-sectional size optimization. Three types of variables (material, topology and size) and two types of constraints (static stiffness and frequencies) are considered to promote this practical design. For multi-material topology optimization, an ordered solid isotropic material with penalization interpolation is used to transform the multi-material selection problem into a pure topology optimization problem, without introducing new design variables. Then, based on the previously optimal topology result, cross-sectional sizes of the bus frame are optimized to further seek the least mass. Sequential linear programming is preferred to solve the two structural optimization problems. Finally, an engineering example verifies the effectiveness of the presented method, which bridges the gap between topology optimization and size optimization, and achieves a more lightweight bus frame than traditional single-material topology optimization.

KEYWORDS:

• Bus frame
• lightweight design
• multi-material topology optimization
• ordered SIMP
• size optimization

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Wenjie Zuo http://orcid.org/0000-0002-2003-6401

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51575226] and China Postdoctoral Science Foundation [grant number 2017T100206].