考虑塑性应变记忆恢复的循环棘轮本构模型研究  

Study on the Cyclic Ratcheting Constitutive Model Considering Plastic Strain Memory Recovery

作　　者：刘秀宇 董亚伟 肖雄 Xiuyu Liu;Yawei Dong;Xiong Xiao(Department of Mechanics and Engineering Science,School of Science,Nanjing University of Science and Technology,Nanjing,210094)

机构地区：[1]南京理工大学理学院力学与工程科学系

出　　处：《固体力学学报》2018年第4期429-438,共10页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金(11502115);江苏省自然科学基金(BK20150777)资助

摘　　要：论文在统一粘塑性循环本构理论框架下,以Ohno-Abdel-Karim非线性随动硬化模型为基础,建立了一个循环本构模型.模型通过引入塑性应变幅值记忆效应,并在塑性应变记忆项中加入恢复系数,提高了对循环硬化材料单轴行为的预言能力.多轴模型中通过引入Tanaka提出的非比例度效应,描述多轴加载中因路径不同产生非比例附加硬化,提高模型对多轴棘轮行为预测能力.通过和实验结果的对比,可以发现：论文模型可以合理的描述316L不锈钢的单、多轴棘轮变形,模拟数据均与实验数据吻合较好,论文模型可以合理地描述循环硬化材料的棘轮变形.Ratcheting,a cyclic accumulation of inelastic deformation occurring in the engineering materials subjected to asymmetrical stress-controlled cyclic loading,can cause the deformation of structures to exceed the designed limitation or shorten the fatigue life of engineering components.Based on the framework of unified visco-plasticity,a new cyclic constitutive model is proposed to describe the ratcheting behavior of cyclic hardening materials on the basis of Ohno-Abdel-Karim model.As we know,the level of cyclic hardening increases with the increase of plastic strain amplitude in the cyclic deformation tests for cyclic hardening materials.Then,the memory surface for the maximum plastic strain amplitude effect is introduced to reflect the effect,and the dynamic recovery coefficient is added to the plastic strain memory term to reflect the effect of maximum plastic strain on isotropic deformation resistance.The definition of Tanaka＇s non-proportionality is adopted to describe the multiaxial ratcheting deformation with different multiaxial loading paths.Then,the proposed model is adopted to describe the stress-strain responses of 316 L stainless steel（which is a kind of cyclic hardening material）under uniaxial tension,strain-controlled cyclic loading and stress-controlled cyclic loading,respectively.Comparing with the corresponding experimental results,it can be found that,the uniaxial and multiaxial ratcheting of 316 Lstainless steel can be reasonably described by the proposed model.Furthermore,the model can also properly reflect the various degrees of extra hardening with different proportional and non-proportional loading paths.To sum up,the capability of the proposed model to predict the uniaxial and multiaxial ratcheting behaviors of cyclic hardening material is well improved by introducing the effect of plastic strain memory recovery.It is believed that the proposed model is useful for the design and fatigue life prediction of engineering components.

关 键 词：棘轮行为 本构模型 Ohno-Abdel-Karim模型 非比例附加硬化 塑性应变记忆恢复 

分 类 号：O344.1[理学—固体力学]