耦合孪生晶体塑性模型硬化参数的灵敏度分析

发布时间：2019-04-12 16:57

【摘要】：基于经典晶体塑性理论,建立了耦合孪生的晶体塑性本构模型并进行了全隐式积分的数值实现.该本构模型采用饱和硬化法则,并采用孪生阻力与滑移硬化之间的正比关系来描述孪生对滑移硬化影响及孪生硬化行为.针对该本构模型的13个参数,结合各参数物理意义提出了参数的分类确定方法.以孪生诱导塑性(TWIP)钢Fe-22Mn-0.6C为例,着重对硬化参数的局部灵敏度进行了分析,研究了各硬化参数对宏观力学响应、孪生激活和演化的影响,根据变形机制的不同宏观变形过程可区分为孪生硬化阶段和孪生硬化失效阶段,进而给出了硬化参数确定的步骤及其建议取值范围.结果表明:初始滑移阻力与屈服极限线性相关,取值范围在80~160 MPa之间;孪生硬化指数增大使得孪生硬化阶段减弱,其取值范围应在0~3之间;孪生阻力与滑移阻力比值增大,则孪生增长率降低,硬化率拐点后移,直至拐点消失,其取值范围在1~1.3之间.
[Abstract]:Based on the classical crystal plasticity theory, the coupled twin constitutive model of crystal plasticity is established and the fully implicit integral is realized numerically. The law of saturation hardening is adopted in this constitutive model and the proportional relation between twin resistance and slip hardening is used to describe the effect of twin on slip hardening and the behavior of twin hardening. According to the 13 parameters of the constitutive model and the physical meaning of each parameter, the classification and determination method of the parameters is put forward. Taking twin-induced plastic (TWIP) steel Fe-22Mn-0.6C as an example, the local sensitivity of hardening parameters was analyzed, and the effects of hardening parameters on macro-mechanical response, twin activation and evolution were studied. According to the different macro deformation process of deformation mechanism, it can be divided into twin hardening stage and twin hardening failure stage, and then the steps of determining hardening parameters and the suggested range of values are given. The results show that the initial slip resistance is linearly related to the yield limit, the range of values is between 80 and 160 MPa, the increase of twin hardening index makes the twin hardening stage weaken, and the value range of the initial slip resistance is between 0 and 3. When the ratio of twinning resistance to slip resistance increases, the twinning growth rate decreases, and the inflexion of hardening rate moves back until the inflection point disappears, and the range of values is between 1 and 1.3.
【作者单位】：北京科技大学机械工程学院;宝山钢铁股份有限公司;
【基金】：国家自然科学基金资助项目(51105029,51575039) 国家自然科学基金委员会-中国工程物理研究院联合基金资助项目(U1330121) 非线性力学国家重点实验室开放基金资助项目(LNM201512) 北京市自然科学基金资助项目(3112019) 北京市教委重点基金资助项目(KZ201010005002)
【分类号】：TG111

【参考文献】