Investigation on the effects of suspension stiffness using experimental modal analysis and finite element model updating

The model validation process known as the finite element model updating method aims to improve the accuracy of the predicted results by reducing the discrepancies between the initial finite element model and the experimental data. The objective of this paper is to investigate the effects of the suspension spring stiffness to the experimental data. Experimental modal analysis with free-free boundary conditions is conducted on the slender beam to measure the modal parameters. The finite element analysis is performed to obtain the natural frequencies and the mode shapes. The results from both methods are compared to investigate the discrepancy of the finite element model of the suspension spring. Firstly, the initial model of the slender beam is updated to reduce the discrepancy between the experiment data and the initial finite element model of the slender beam. Finally, model updating method is performed to the suspension stiffness of the spring and the result shown effectiveness finite element updating method in reducing the discrepancies between the initial model of the stiffness of the suspension spring and the measured result from 33.23 % to 3.05 %.