Optimal Substitution of Lightweight Materials in Automobiles 800828
Development of lightweight materials has provided the automotive industry with numerous possibilities for vehicle weight reduction. The usage of these materials will depend upon their economic feasibility as well as their material properties. Often, managers will compute the penalty-per-pound saved in a given application for a number of competing materials to determine which is cost-effective. However, this method has limited usefulness in larger dimensioned problems where an overall weight requirement is to be met by employing a large number of candidate materials in any number of component applications. When there are several component-material combinations under simultaneous consideration, attention should focus on; (1) which set of materials minimize total cost while meeting a particular weight constraint and; (2) how the solution set of materials changes as the weight constraint is varied.
This paper presents a relatively simple technique useful for determining the most economically attractive materials mix given the weights and costs of all material-component combinations and an overall weight target. The technique has been applied to a production mid-sized vehicle to obtain optimal material mixes for 26 structural components. The competing materials include mild steel, aluminum, high strength low alloy steel (HSLA), E-glass and five different graphite reinforced plastic hybrids. A computer program was developed to perform the necessary calculations. The results of several cases are presented and analyzed.