A Comparative Study of CWELD and ACM2 Element Connectors on the Dynamic Behaviour of a Laser Spot Welded Hat-Plate Structure under Initial Stress Influence

Abstract

Analytical modelling of the dynamic behaviour of a laser spot welded structure can be developed using two element connectors which are CWELD and ACM2. In the presence of initial stress in the structure, the performance of these two connectors can be different. In order to properly investigate the dynamic behaviour of the structure, the difference of these two element connectors in representing the laser spot welded in the structure should be evaluated. The finite element method was used to develop the welded structure comprising two structural components. The element connectors were then used to represent the laser spot welds in the structure. Normal modes analysis was performed on the FE model of the welded structure to calculate the modal parameters. Experimental modal analysis was carried out to measure the modal parameters of the physical welded structure. The modal parameters calculated from the two different FE models were evaluated by the experimental counterparts in terms of natural frequencies, mode shapes and MAC value. The accumulated error registered from all 6 modes from the CWELD element connector FE model is 10.59%. Meanwhile, the accumulated error calculated from all 6 modes of the ACM2 element connectors based FE model is 26.67%. It was found that the FE model with CWELD element connectors has shown a good correlation with the physical welded structure. The findings can have an important effect on how analytical modelling of the dynamic behaviour of the welded structure under initial stress can be effectively and accurately carried out.