The reconciled finite element model of riveted joints structure for crash analysis / Nor Munirah Hassin

In the automotive structure, a different type material structure partially employing aluminium alloy sheets may be adopted in order to achieve higher strength and better formability for light weighting and crashworthiness. The structures are assembled from components connected by various types of joints and the dynamic properties of the joints are difficult to incorporate in the model numerically accurately due to invalid assumption of input values. The accuracy of the predicted model is significantly affected by the input properties of the joints. In this research, the dynamic behaviour of a simplified model of crash box structure that is joined by a number of riveted joints was investigated. Different types of connector elements were investigated and their accuracy was discussed in terms of natural frequencies and mode shapes. In order to achieve these goals, the predicted results are compared with the experimental data. Moreover, the re-conciliation method known as iterative finite element model updating is used to minimise the discrepancy between the experimental results and the predicted results of finite element model of crash box. In this research, the effectiveness of updated model of the crash box is then used for the crash analysis using crash simulation ABAQUS/explicit, and at the end of this research, the updated model was compared with the initial model in terms of Crush Force Efficiency (CFE), Initial Peak Force (IPF) and Specific Energy Absorption (SEA). Based on evaluation of the crash data, all of the relative errors of the three criteria of impact response of updated model were found closer to the experimental drop test in comparison with the initial model of the double hat shape. It is shown that the updated finite element model of the crash box provides a better correlation with the crash experimental result.