【作者】 陈家权； 陈国军； 赵政飞； 吴燕瑞； 温洁明；

【Author】 Chen Jiaquan,Chen Guojun,Zhao Zhenfei,Wu Yanrui,Wen Jieming (College of Mechanical Engineering,Guangxi University,Nanning 530004,China)

【机构】 广西大学机械工程学院；

【摘要】 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表征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了修正,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。此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,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本文方法的准确性进行了验证。分析结果表明,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。更多还原

【Abstract】 Research shows that the plastic strain of multiaxial cyclic constitutive relations of material under non-proportional loading not only depends on the stress state,but also closely relates to the strain path. According to mechanism of material additional hardening produced under multiaxial non-proportional loading,analysis and calculate the plastic strain energy correlated to the strain path based on the critical plane method.The cyclic strength coefficient and cyclic strain hardening exponent of the multiaxial cyclic equivalent stress-strain relationship were amended based on the Osgood-Ramberg equation,and combinated with the strain energy and the equivalent strain composed by the Von-Mises criterion.A prediction method for multiaxial cyclic constitutive relationship is presented by considering the impact of the mean strain,which can reflect the relevance of the strain path.This method takes into account of the impact of the stress state and strain path on the multiaxial cyclic constitutive relation based on material produce plastic deformation and fatigue damage mechanisms,the accuracy of this method was verified with selected fatigue test data of 45 steel and 40CrMo steel under several typical strain paths.As results show,the method can be applied to both proportional and non-proportional loading,predicted results of multiaxial cyclic stress response for steady-state are in good agreement with experimental results.It is convenient for engineering application for simple prediction.更多还原