Simplified Fatigue Life Analysis of Pipeline under Super Multi-Support and Multi-Dimension Excitations Based on Pseudo Excitation Method

In view of the problem that the calculation scale of the traditional random vibration module is not applicable under the super multi-point random vibration boundary conditions, and the traditional fatigue life analysis method is restricted by the heavy modeling workload, it is unable to complete the fatigue life analysis quickly, based on the virtual excitation method, a simplified fatigue life analysis method for pipeline system with super multi-point and multi-dimension excitation is proposed in this paper. The applicability of the virtual excitation method is verified by comparing the structural dynamics response calculated by the virtual excitation method and the traditional random vibration module, and the fatigue life of straight pipe structure and tee connection position is analyzed by using pipeline simplified fatigue life analysis method and traditional fatigue life analysis method. The results show that the accuracy of random vibration response calculated by the virtual excitation method is consistent with that of the traditional random vibration module, which shows that the method proposed in this paper can break through the limitation of the traditional random vibration module on the number of vibration excitation points and frequency points; The method proposed in this paper does not need to establish a detailed finite element model, and the stress and life analysis results of the straight pipe structure are basically consistent with the fine model, and the stress and life analysis results of the tee connection position are more conservative than the fine model. The research in this paper can provide theoretical guidance for the rapid fatigue life analysis of complex vibrating pipeline systems.