| Summary: | An accurate analytical model of the physical assembled structure is predominantly importance for engineers and designers to be used in predicting the dynamic behaviour of the structure. Powerful tools such as finite element analysis (FEA) and experimental modal analysis (EMA) can be used to determine the dynamic behaviour of the assembled structure. The assembled structure such as automotive structure is normally joined by a number of jointing types such as spot welds, bolts, and adhesive. However due to advancement of the jointing method, the laser jointing method have been significantly used in the automotive industries. However, it is challenging and cumbersome to accurately model a structure that are assembled by a combination of complex types of joints such as laser stitch welds. This is because stitch welds have been discovered as joining method that tends to present the local effect such as structure geometrical irregularities, heat affected zone (HAZ) on the welded areas and also the residual stress that occurs from the laser welding process. In addition, it is challenging to only rely on the prediction of the dynamic behaviour using FE method because predicted results are often found inconsistent with the experimental data. The inconsistencies of the results due to invalid assumptions of laser stitch welds are the significant motivation to the main goal of this paper by investigating the accuracy of the finite element model of the laser stitch welded structure. In this paper, the prediction of the dynamic behaviour of the structure are merely to address the local effects due to the laser stitch welds such as geometrical irregularities, HAZ and residual stress that influence the initial prediction of the laser stitch welded structure by producing highly accurate prediction model as close to experimental data. The inclusion of the local effects to the initial FE model are performed in the sensitivity analysis to identify the most sensitive parameters of the laser stitch welded structure. The FE model updating method was employed with corresponding to the measured result for reconciliation purpose. The results revealed that the inclusion of the local effects due to the welding process can significantly improve the prediction of the dynamic behaviour of the laser stitch welded structure and the implementation of the sensitivity analysis was successful in correcting the source of error by improving the correlation of the predicted results with experimental counterpart. © 2024 American Institute of Physics Inc.. All rights reserved.
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