【摘要】 本文通过分析疲劳破坏的本质,并借鉴目前应变能理论的最新成果,提出了一种随机复杂应力场下基于塑性应变能的疲劳寿命分析模型,以此来预测材料的多轴低周疲劳寿命.模型中的相关材料参数通过MATLAB拟合单轴及纯剪切疲劳试验数据得到,使用有限元软件ANSYS模拟试件的多轴加载情况,并从其后处理程序中提取模型中需要的数据.通过对光滑试件SM45C,304和缺口件GH4169,16MnR的计算验证,其结果表明该模型对多轴随机应变加载低周疲劳寿命具有很好的预测效果.更多还原

【Abstract】 This paper proposes a fatigue life prediction model,based on plastic energy under random complex stress field loading,by analyzing the nature of fatigue damage and using the latest achievements of the strain energy theory for reference,to predict material’s fatigue life under multi-axial low cycle loading.Using fatigue data under uniaxial and pure shear tests to fit relevant material parameters of the model by MATLAB.Then,using ANSYS to simulate multi-axial loading conditions of the specimen and extract needed data in the model from its post processer.Computing validation of smooth specimens SM45 C,304and notched specimens GH4169,16 MnR indicates that the model can predict the low cycle fatigue life under multi-axial random strain loading well.更多还原