An efficient structural vibration damage evaluation method based on the spectral element method

Abstract

Various spectral methods have been developed for vibration fatigue analysis, with frequency domain analysis being commonly applied. However, almost all existing frequency domain analysis methods rely on vibration analysis models established by finite element method (FEM). The large number of meshes and the computation and storage of complex stress frequency response functions (FRF) greatly limit the efficiency of this approach. In this paper, a novel vibration failure analysis method based on spectral element method (SEM) is proposed. Compared to traditional methods, this approach offers two main advantages. First, it reduces the number of required elements by 94.5 %, significantly decreasing the dimension of the stiffness matrix. Second, it enables the direct solution of all problems in the frequency domain, eliminating the need for Fourier transforms and modal superposition. As a result, the total computational time can be reduced by up to 46.4 % compared to conventional FEM-based methods, making iterative structural optimization feasible. A scaled model of a fuel cell engine frame is presented as a case study. The proposed method first rapidly computes the damage distribution information of the frame under specified working conditions. Subsequently, utilizing this information, the artificial bee colony (ABC) algorithm is employed to adjust the dimensions of relevant components in order to achieve an optimal structure that meets the criteria. This method demonstrates favorable consistency in both vibration experiments and comparisons with traditional frequency domain simulation methods.