Dynamic behaviour prediction and optimisation of an assembled structure using meta-modelling based updating.

Recently, laser stitch welds are prefered in automotive structure comparing with others joining methods when joining two or more substructures due to its capabilities producing high strength joint with low heat application. However, the vibration responses such as dynamic behaviour of laser stitch welded structure are complex and there is a variety of uncertainties in predicting the behaviour of the jointed structure. Therefore, fast-running meta-modelling tools such as response surface (RSM)-based model updating are needed in accurately predict the vibration responses of the welded structure. In this paper, FE modelling scheme for represent laser stitch welds and the use of RSM-modal updating method for improving the dynamic behaviour of the FE model are presented. Initially, element connectors such as CBAR, CQUAD and ACM2 format are implemented to model the laser stitch welds in the FE models. Then, the correlation of the dynamic behaviour obtained from the FE models are compared with the experimental counterparts. In order to improve the accuracy of the FE models in comparison with experimental data using fast-running optimization method, combination of model updating method (NASTRAN SOL 200) and RSM is used. The results show the capabilities of RSM in optimising the predicted dynamic behaviour of the welded structure. [ABSTRACT FROM AUTHOR]