Structural optimization with crashworthiness constraints

Abstract

An automated structural design methodology has been devised which simultaneously considers design criteria associated with both linear elastic and crashworthiness loading conditions. This method is developed within the context of a nonlinear mathematical programming based structural optimization capability using an efficient two-phased crashworthiness analysis technique. Specially constructed nonlinear approximations for the crashworthiness constraints are employed to further reduce the computational burden during the optimization process. This methodology is demonstrated on an automobile structural design problem. It is shown that more mass efficient designs can be obtained by simultaneously considering elastic and crashworthiness design criteria as compared to a sequential approach in which the structure is first designed for the elastic loads and then modified to satisfy the crashworthiness criteria.

Optimization of Multibody Systems Using Approximation Concepts

“…In Chapter 3 it has been remarked that both single-point and multi-point approximations can be improved by inclusion of suitable intermediate design variables and responses. Lust ( 1992), for example, showed that for structural crash worthiness constraints, such as the vehicle crash severity index, intermediate design variables and responses can be defined that yield more robust constraint approximations. Probably many more can be found, reflecting the mathematical and physical background of the crashworthiness responses.…”

Analysis of the coach rollover scenario

“…Lumped parameters models have been proposed by Lust [6] and Kim et al [7] for crashworthiness structural optimization in the first stages of the design process. Mahmood et al [8] described in detail a procedure for rapid simulation and design of the frame of an automotive structure and Cheva et al [9] used lumped mass models for frontal/offset crash studies.…”

Development of simplified models for design and optimization of automotive structures for crashworthiness

“…It was also observed that the energy absorption capacity of the cylindrical tube was slightly better than that for the square tube for the same mass of the tubes. Lust (1992) considered optimization of automotive structures with constraints based on both linear elastic and crashworthiness loading conditions. A two phase crashworthiness analysis approach was used.…”