CAJ | 학술논문

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.
침대고온피로중연변화양화인소적영향,제출고온순배가재하시간상관피로손상모형.근거재료고온피로미관관찰화피로과정,충분고필랍압응변솔화순배주기불동이조성적불동손상,제출고온영향절산시간적계산방법.결합손상이론화고온대피로손상적영향,파무보재시간적고온피로손상분위순피로손상、시간상관손상화교호손상,손상모형경고온2.25Cr-1Mo강단다축피로시험험증,결과표명,오차재량개인자지내.
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-1Mo steel tests under uniaxial and multiaxial high temperature fatigue showed an error within a factor of two.