Improving finite element modelling of the dynamic behaviour of a car trunk lid with modal based updating method

Predicted results of a finite element model used to develop physical test structures are often found to be not in a good agreement with the experimental results due to the invalid assumptions made in the finite element modelling. This study will focus on improving the correlation level between the finite element model and experimental model of a car trunk lid with the presence of resistance spot welded joints using modal based updating method. The natural frequencies and mode shapes computed from the updated finite element model of the car trunk lid are compared with the corresponding experimental results. HyperWorks and Leuven Measurement System (LMS) test are used for the modelling and modal testing. MSC Nastran SOL200 is used to identify potential updating parameters and to improve the initial finite element model in the light of corresponding experimental results which are obtained from modal testing. The comparison of the results showed that the total error of 58.59 per cent predicted from the initial finite element model of the trunk lid has been successfully reduced to 3.62 per cent. In conclusion, modal based updating has been successfully used to improve the correlation level between the initial finite element model and the physical model of the trunk lid.