应用有限单元法耐高压观察窗疲劳寿命分析

Fatigue Life Analysis of High Pressure Observation Window Based on Finite Element Method

耐高压观察窗是深海装置的重要组成单元,受到海水液力和高压的作用,容易发生疲劳损伤,进而影响装置的使用寿命。基于锥台式耐高压观察窗的结构特点,对观察窗的疲劳载荷和所受的液动力进行分析;基于观察窗载荷谱和有机玻璃的S-N曲线,进行有限单元法建模仿真分析,并根据Miner线性累积损伤理论公式,分析观察窗的疲劳损伤,获得使用寿命;搭建观察窗压力试验装置,获得观察窗压力载荷作用下的轴向位移,根据蠕变损伤模型,对疲劳寿命进行分析,获得观察窗的使用寿命。结果可知:有限单元法获得观察窗的使用寿命为21359 Circle;试验分析获得观察窗的使用寿命为21326 Circle;两种方法获得的分析结果误差在1.5%,可认为二者基本一致,表明模型仿真的可靠性和准确性;为此类研究提供重要参考。

High-pressure observation window is an important component of deep-sea installations.Under the action of seawater hydraulic force and high pressure,fatigue damage is likely to occur,which will affect the service life of the device.Based on the structural features of the high pressure observation window of the cone table,the fatigue load and hydraulic force of the observation window are analyzed.Based on the load spectrum of the observation window and the S-N curve of the plexiglass,finite element method modeling simulation analysis is implemented.According to Miner’s linear cumulative damage theory formula,the fatigue damage of the observation window is analyzed and the service life is obtained.The observation window pressure test device is built to obtain the axial displacement under the pressure load of the observation window.According to the creep damage model,the fatigue life is analyzed to obtain the service life of the observation window.The results show that the service life of the observation window obtained by the finite element method is 21359 Circle.The service life of the observation window obtained by experimental analysis is 21326 Circle.The error of the analysis results obtained by the two methods is 1.5%,which can be considered to be basically the same,indicating the reliability and accuracy of the model simulation;providing an important reference for such research.