Sensitivity analysis method for frequency response function based on extended transfer matrix method for linear multibody systems

Abstract

The sensitivity analysis for frequency response function is of great importance in the areas of system identification, model updating, dynamic optimization, vibration control and structural damage detection, et al. In allusion to the problems resulting from the prohibitive computational cost using the direct method and the modal truncated errors using the modal superposition method, a novel sensitivity analysis method for frequency response function based on the extended transfer matrix method for linear multibody systems is proposed. The sensitivity transfer equations of elements and system are established utilizing the direct differentiation method, from which the frequency response function sensitivity can be accordingly obtained. The results are also used to the sensitivity analysis for random vibration response. The proposed strategy is analytically and numerically validated by examples, indicating that it not only inherits the advantages of transfer matrix method for multibody systems that the system global dynamics equations are not needed, the system matrix order is low, the solution procedure is highly stylized, and the computational speed is high, but also achieves accurate computation of frequency response function sensitivity without modal truncation and the assumption of proportional damping.