Abstract
Research and/or Engineering Questions/Objective
Linear static response structural optimization has been developed fairly well by using the finite element method for linear static analysis. However, development is extremely slow for structural optimization where a nonlinear dynamic analysis technique is required. Topology optimization considering dynamic nonlinear behavior of mechanical structures, e.g. automotive crashworthiness remains a challenge in both the implementation as well as computational effort. In recent years, efficient optimization algorithms and increased computer technology has begun to allow the development of methodologies to examine optimal topology of structures undergoing such behavior. Crashbox is an important energy absorber component of front structure, so it must be designed to meet the requirements of crashworthiness.
Methodology
The traditional approach for solving topology optimization problems is based on sensitivity analysis that is inexpensive to obtain for linear-static problems. However, deriving analytical sensitivities for dynamic analysis is very difficult .Numerical computation of sensitivities is also not practical due to the high computational expense. To overcome the difficulties in topology optimization, a different approach: HCA（Hybrid Cellular Automaton）was proposed. This approach does not require gradients and hence there is no need to compute the sensitivities. This method utilizes the cellular automata computing paradigm with the nonlinear transient finite element analysis. Previous work in topology optimization for structural design has concentrated on modeling assuming static loading conditions due to the complexities associated with dynamic loading. A HCA method has been developed to address more complicated cases that involve dynamic events, such as impacts and collisions.
Results
New type of crashbox would be designed in given domain by application of HCA. Its energy absorption effect would be better than the original design, and it would be lighter. HCA would be proved that it is an effective method for crashworthiness optimization design Limitations of this study The study presented in this paper is just about HCA method, there is no other optimization methods for nonlinear dynamic problems are compared. This paper is only applied at simulation method designed to optimize crashbox, no experimental verification.
What does the paper offer that is new in the field including in comparison to other work by the authors?
The application of HCA for vehicle crashworthiness design presented in this paper is new field for vehicle optimization design research. The optimization method can develop lightweight design.
Conclusions
HCA would be proved that it is an effective method for crashworthiness optimization design.
Key Words : Crashworthiness; HCA; Crashbox; Topology optimization; Lightweight