预载荷作用下管路结构动强度评估方法

针对现阶段航空航天管路结构环境试验存在的问题,研究了管路结构在预载荷及随机振动试验条件作用下的动强度特性的分析方法,明确了由预载荷引起的微分刚度、预应力在结构振动响应计算及疲劳寿命分析时的区别及处理方法,提供了一种可定量预估管路结构在多种试验环境作用下随机振动疲劳损伤的分析方法,该方法解决了真实环境试验条件如何表示预期使用环境的问题以及真实环境试验条件与预期使用环境不一致对管路结构动强度造成的影响如何进行评估的问题。通过对管路结构的仿真，分析了管路的动强度薄弱点以及剩余强度系数和疲劳寿命,验证了该方法的有效性,从而为分析管路结构在真实使用过程中的环境适应性以及可靠性提供了一定工程指导。

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.