Investigation of the Effect of Different Spot-Weld Modeling Approaches on Fundamental NVH Virtual Simulations 2014-01-0025

The main objective of this study is to investigate the effect of spot-weld modeling approaches on NVH virtual simulation problems. For this purpose, finite element method is considered for further simulations. The goal is to evaluate and compare results within the domain of 0 to 200 Hz by modeling spot-welds with three different element types: a rigid body constraint element (RBE), two rigid body elements with hexahedral solid element (RBE3-HEXA-RBE3) and CWELD constraint. In order to evaluate the effects, three main NVH analyses are chosen for this study. In the first place, a free-free modal analysis is performed for the BIW and trimmed body models of a D-segment saloon car in order to estimate natural frequencies and mode shapes. Afterwards, a frequency response analysis is performed to evaluate the dynamic stiffness of engine mount. Finally, a noise transfer function (NTF) simulation is carried out to calculate the sound pressure level at driver ear's location. The out coming results from each type of simulations are extracted and compared to investigate the effect of spot-weld modeling on the accuracy of FEM analyses results concerning NVH problems.