OPTIMIZATION OF AN AUTOMOTIVE STRUCTURE SUBJECT TO HARMONIC EXCITATION

Optimization theory has been used to obtain solutions to a variety of engineering problems involving beam vibration. In this study, the objective is to design a structure that uses the minimum amount of material. The structure examined is a beam undergoing coupled bending and torsion, as is common in automotive structure beams. The objective of this study is to minimize the weight of an automotive structure subject to harmonic excitation. The automotive structure is modeled with beam elements in I-DEAS, a computer-aided engineering and finite element software. For each given length, its cross-sectional area is optimized by a discrete finite element method. In addition, a bracket was modeled in conjunction with the automotive structure. Although the optimal design of beams undergoing forced harmonic loading is available in the literature, to the authors' knowledge, optimal design of such structures including an intermediate support have not been considered. The placement of the bracket was also treated as a design parameter by varying its location and size in the optimization process. Results show that the total mass after optimization had a mass reduction of 91% when compared to the original weight.