Attachment parts connected to the truck frame are vibrating due to road or powertrain excitations. Because of the mass of the attached parts these vibrations lead to high structural loads within the area of the bolted flange between frame and attachment part. Thus a correct dynamic model including the nonlinear contact interactions is necessary for a reliable durability analysis.
In the example model of a side rail attachment the contact interaction between the side rail and the bracket was included with MAMBA. The dynamic response analysis showed a shift of the natural frequencies due to a stiffer coupling. In the linear model the loads are only transferred via the bolt models, which causes unrealistic high local damage. The supporting effect of contacts with MAMBA results in a distribution of the loads and thus the damage is reduced significantly.