Finite element analysis of light motor vehicle subframe for mass optimization

Subframe is the automobile structural module, which is designed to carry specific automotive components like engine and suspension. It is connected to the vehicle body through specific mount locations using bolts and distributes high localized loads over a wider area of the body structure to isolate vibration from rest of the body. In the present study, Finite element (FE) analysis is carried to determine the structural integrity of the designed Light Motor Vehicle (LMV) subframe model in order to minimize the mass. Initially modal and stiffness analysis carried out on base model to extract modal frequencies for the entire model and linear static stiffness values at different locations. Similar analysis carried on design change models with FE iterations lead to design changes in geometry and thickness of the subframe components. Finally the optimized model with less mass, nearer frequency and stiffness values compared to base model is suggested for durability and fatigue analysis. The CAD models were generated using CATIA V5 and the FE analysis of these models were developed in Hypermesh with Optistruct as the solver. Overall 9% of mass reduction is achieved in the final optimized model when compared to base model.