Exact Constraint Design of Vehicle Components 961687

An important basis of the technology strategy of the Partnership of a New Generation of Vehicles (PNGV), is the assumption that major advances in a number of different technologies must be made, before the realization of most of the challenging goals of the new generation of vehicles. One of those technologies is the reliance on lightweight alternative materials in order to produce lightweight components to achieve the projected fuel economy increases. However, this push toward lightweight components should not be on the basis of sacrificing vehicle performance, handling, reliability or safety. Toward this objective, engineers frequently are relying on super-fast computers as well as new approaches to achieve a new generation of designs of automotive components, based on some form of optimization techniques. These techniques however, usually imply increasing the number of constraints imposed on a particular design objective, which is the weight of the vehicle in this case. Treatment of increased constraints of a particular design can by itself generate another optimization methodology to achieve an exact constraint design of a component.

A systematic approach for achieving an exact constraint design of a component, to improve it's impact characteristics is desired at the product development stage, and before the expensive build and test stage. Such a technique can reduce the time and effort needed in the design process as well as the number of tests required for product validation.

A modified random walk method based technique [1] , is expanded here to treat the exact constraint design problem. The method used is targeted toward energy formulation, but it can be demonstrated to be also true for other design targets such as stiffness, strain and stress. Application of this method to achieve maximum impact energy absorption for crashworthiness of an automotive component is described.