Dynamic strength valuation method of pipeline structures under preload

For the problems of pipeline structures environment test in current aerospace, first of all, we researched the analytical method for dynamical strength characteristic of pipeline structures under preload and multiaxial random vibration experiments, and then made clear the difference and processing between differential stiffness and prestress caused by preload in structural vibration analysis and fatigue life calculation. We provided an analysis method to preestimate the fatigue damage of pipeline structure under random vibration in various actual experimental environments, and this method solves the following problems: how the conditions of actual experimental environment tests srepresent the preexperimental environments and how to estimate the effects of inconsistency between the actual experimental environments and the preexperimental environments on dynamic strength of pipeline structures with. Finally, by simulation calculation for pipeline structures, we analysized the weak points and residual strength coefficient of dynamic strength in pipeline structures, as well as the fatigue life. The simulation results verify the effectiveness of this method, thus this analysis method provides engineering guidance for analyzing the adaptability and reliability of pipeline structures in the actual environment.