TPA for internal force identification in a mechanical system

The knowledge of the loads acting on different components of a mechanical system during operating conditions is of particular relevance. For instance, the ability to identify and quantify internal forces can greatly improve the estimation of parameters of a numerical model. In this paper, the identification of internal forces in a mechanical system has been investigated by the application of the Transfer Path Analysis (TPA) technique. TPA can be summarized as a test based approach which allows the analysis of the contribution of different vibration paths in a structure. A crucial step of the entire procedure is determined by the calculation of the forces exciting the structure. Different approaches are available for this purpose. Here, the Matrix Inversion (MI) method is used. The mechanical system under examination is a bearing test rig. The aim is to estimate internal forces acting at the proximity of the bearings, under operating conditions, by the implementation of the TPA technique with the specific MI method. A Monte-Carlo simulation is also performed as a measure of the sensitivity of the method to errors in the experimental Frequency Response Function matrix. The internal forces are also directly measured by load cells installed at the specific locations, making this test rig an ideal tool for validation of the proposed technique. In addition, a multi-dof model of the test rig is implemented. A simulation of the TPA procedure on this model is used to fully understand the outcome of the experimental study. Positive results prove the applicability of the presented approach for the identification of internal forces.

Publication year:2013

Accessibility:Open