Experimental-analytical state-space synthesis of passenger car components

Paper in proceeding, 2018

In this paper an experimental model of a Volvo XC90 body-in-white and a finite element model of a rear subframe are coupled for vibration assessment using a state-space synthesis method. This problem is challenging due to the complex structures considered. They are exhibiting high modal densities, high damping and the coupling is through four rubber bushings. The models are connected through four virtual points created at each coupling position. The state-space synthesis method relies on a system identification procedure for the experimental model, which in itself pose a significant challenge for the modally dense body-in-white. In this paper a newly proposed system identification technique focusing not to the least on direct accelerances, based on a subspace state-space method, is used. It also aims to fulfil physically motivated constraints. Results from the coupled system are shown to agree well with experimental data of the system assembly, and the method outperforms a finite element based coupling.