Body Torsional Stiffness - Validation & Design Optimization

Abstract

This Thesis is a validation work, wherein, the body torsional stiffness calculated from a test-rig experiment is validated against the simulations. Earlier, the body torsional stiffness was calculated in the test-rig using a Body-In-Gray (BIG) structure (see section 2.2) and this method correlated exactly with the CAE simulation method. Hence, this test-rig experiment method was stopped and the simulations were enough for evaluating the body torsional stiffness. Later, a new test-rig experiment method (current method) was introduced, in which a full-scale car model is used to evaluate the body torsional stiffness. This method was introduced mainly to measure and compare the body torsional stiffness of the competitors’ models. As this method did not correlate well with the CAE simulation, the impact of the Chassis on the BIG model is investigated. This is done to get a better correlation of the results between the simulation and the test-rig experiment. Also, to evaluate the body torsional stiffness similar to that of the test-rig method, a new simulation method is introduced during the thesis. Finally, the results from both the simulations are compared against the test-rig method to recommend the best simulation method for validating the test-rig experiment. As a second part of the thesis, a Design Optimization study is performed to reduce the weight of the BIG structure with no change in the body torsional stiffness.