局部应力应变疲劳的能量方法  

Energy method of local stress and strain fatigue

作　　者：徐楠[1] 陈举华[1] 

机构地区：[1]山东大学机械工程学院,山东济南250061

出　　处：《山东大学学报（工学版）》2006年第1期15-18,共4页Journal of Shandong University（Engineering Science）

基　　金：山东省自然科学基金项目(Y2002F19);山东省科学技术发展计划项目(012050107);山东省技术创新项目(鲁经贸技字2003[182])

摘　　要：应用Neuber准则分析弹塑性材料缺口件时局部应力应变估计过高,因此预测初始寿命常给出过于保守的结论.由于当量应变能密度(Equivalent strain energy density,ESED)准则在Neuber准则的塑性变形项上增加了系数,局部应力应变估计结果更为准确.基于能量方法讨论了循环加载下材料的塑性应变能密度,发现ESED准则相比Neuber准则多考虑了塑性应变能密度,这是ESED准则局部应变场估计值远低于Neuber准则的估计值的能量理论基础.疲劳试验的结果验证了以上结论.Analysis of notched specimen of elastic-plastic materials by using Neuber rule always lead to over high estimated values of local stress and strain. So conservative initial-life results were usually obtained. Since the coefficient was added to equivalent strain energy density rule on the basis of the plastic deformation item of Neuber rule, the local stress and strain estimation results should be more accurate. According to energy method, elastic-plasticity strain energy density of material in the case of cyclic loading was discussed. It was discovered that the plastic strain density was taken into account by the ESED rule, and this was the energy theory basis for the further lower values of local stresses estimated by ESED rule than those obtained by Neuber rule. The above conclusion agreed well with fatigue test.

关 键 词：疲劳 能量理论 Neuber准则 当量应变能密度准则 

分 类 号：O346.2[理学—固体力学]