一种多轴循环本构关系预测方法  

A predicting method for multi-axial cyclic constitutive relationship

作　　者：陈家权[1] 陈国军[1] 温洁明[1] 赵政飞[1] 吴燕瑞[1] 

机构地区：[1]广西大学机械工程学院,南宁530004

出　　处：《塑性工程学报》2011年第2期97-102,共6页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(50369001);广西研究生教育创新计划资助项目(2010105930802M)

摘　　要：该文研究表明,非比例加载下材料多轴循环本构关系中,塑性应变不仅与应力状态有关,还与其应变路径密切相关。根据材料在多轴非比例加载下产生附加强化的机理,基于临界平面法,分析和计算能够表征与应变路径相关性的塑性应变能;在Osgood-Ramberg方程的基础上,结合塑性应变能和利用von-Mises准则合成的等效应变,对多轴循环等效应力应变关系中的循环强度系数和循环应变硬化指数进行修正,并考虑了平均应变的影响;提出一种能反映应变路径相关性的多轴循环本构关系的预测方法。该方法基于材料产生塑性变形和疲劳损伤的机理,考虑了应力状态和应变路径对多轴循环本构关系的影响,并利用45钢和40CrMo钢,在多种典型应变路径下的疲劳试验数据,对该方法的准确性进行验证。结果表明,该方法能同时适用于比例与非比例加载,多轴循环稳态应力响应的预测结果与试验结果吻合良好,方法简单,便于工程应用。Researches show that the plastic strain of material in the multi-axial cyclic constitutive relations under non-proportional loading is related to the stress state and the strain path.According to mechanism of the material producing additional hardening under multi-axial non-proportional loading,the plastic strain energy correlated to the strain path was calculated based on the critical plane method.The cyclic strength coefficient and cyclic strain hardening exponent of the multi-axial cyclic equivalent stress-strain relationship were amended based on the Osgood-Ramberg equation,combined with the strain energy and the equivalent strain composed of the von-Mises criterion,with the impact of the mean strain being considered.A prediction method for multi-axial cyclic constitutive relationship was presented which can reflect the relevance of the strain path.This method based on the plastic deformation produced and the fatigue damage mechanisms of the material takes into account the impact of the stress state and strain path on the multi-axial cyclic constitutive relation.The accuracy of this method was verified with fatigue test data of 45 steel and 40CrMo steel under different typical strain paths.The results show that the predicted results of multi-axial cyclic stress response for steady-state are in good agreement with experimental results;the method is simple and can be applied to both proportional and non-proportional loading for engineering application.

关 键 词：多轴疲劳 本构关系 应变路径 非比例加载 临界平面法 塑性应变能 

分 类 号：O346.2[理学—固体力学]