中文摘要：

以某型塔吊液压式伺服阀阀套为例,采用雨流计数法处理其承受的周期载荷;采用经典处理S-N曲线（应力-循环次数关系曲线）的方法得到阀套材料440C的安全S-N曲线;针对用雨流计数法得到的载荷谱中的每一种工况,采用有限元分析软件MSC.PATRAN进行应力分析,得到每一种工况下的最大应力值;对照安全S-N曲线,找到每一最大应力值对应的损伤值,并将所有工况下的损伤值与循环次数相乘并求和,即可得到阀套的疲劳损伤值。采用的疲劳损伤计算方法与传统的疲劳试验方法相比,不仅计算时间比传统疲劳试验时间短,成本低,而且不会因为试件制造过程的缺陷等因素而使计算结果发散。

英文摘要：

Considering a tower crane hydraulic servo valve pocket, the cycle loads on which are handled by the rainflow-counting method and the safe S-N （Stress-Number of cycle） curve of the material used in valve pocket （440C） is obtained according to the classic processing method on the S-N curve firstly. Secondly, for each working condition in load spectrum, the maximum stress value is obtained during the finite element analysis on the MSC. PATRAN software platform. And then, consulting to the safe S-N curve, the fatigue damage value of each maximum stress value is obtained. Finally, the multiplying the fatigue damage value by cycle times, and the sum of which is the total fatigue damage value of the valve pocket. Comparing with method on the fatigue damage proposed in this paper can not only independent of the test specimen defects. the traditional fatigue test, the computational save the analysis time and cost, but is also