高温时间相关单多轴疲劳损伤模型  

HIGH TEMPERATURE TIME DEPENDENT UNIAXIAL AND MULTIAXIAL FATIGUE DAMAGE MODEL

作　　者：孙国芹[1] 尚德广[1] 李承山[1] 

机构地区：[1]北京工业大学机电学院,北京100022

出　　处：《机械强度》2009年第6期1004-1006,共3页Journal of Mechanical Strength

基　　金：国家自然科学基金(0172010);北京市人才强教计划项目资助~~

摘　　要：针对高温疲劳中蠕变和氧化因素的影响,提出高温循环加载下时间相关疲劳损伤模型。根据材料高温疲劳微观观察和疲劳过程,充分考虑拉压应变率和循环周期不同而造成的不同损伤,提出高温影响折算时间的计算方法。结合损伤理论和高温对疲劳损伤的影响,把无保载时间的高温疲劳损伤分为纯疲劳损伤、时间相关损伤和交互损伤,损伤模型经高温2.25Cr-1Mo钢单多轴疲劳试验验证,结果表明,误差在两个因子之内。Time dependent fatigue damage model under cyclic loading was proposed by considering the effect of creep and oxidation at high temperature on the fatigue damage. The high temperature fatigue damage without holding time was divided into pure fatigue damage, damage caused by the time dependent factors and interactive damage to combine effect of high temperature to fatigue damage with the damage rule. The converting time influenced by high temperature was proposed according to tension-compression strain rate and different cycle period based on the SEM（scanning electron microscope） observation of the fatigue rupture surface and fatigue process. The results for 2,25Cr-lMo steel tests under tmiaxial and muhiaxial high temperature fatigue showed an error within a factor of two.

关 键 词：高温 多轴 疲劳 时间相关 损伤模型 寿命预测 

分 类 号：O346.23[理学—固体力学]