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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.
Based on the classical plastic theory of plasticity, the crystal plastic constitutive model of coupled twin was established and the numerical implementation of total implicit integration was carried out. The constitutive model adopted the principle of saturated hardening and adopted the proportional relation between twin resistance and sliding hardening Describe the effect of twins on the slip hardening and the twin hardening behavior.According to the 13 parameters of the constitutive model and the physical meaning of each parameter, the method of determining the parameters is proposed.With twin induction plasticity (TWIP) steel Fe-22Mn-0.6C as For example, the local sensitivity of the hardening parameters is analyzed. The influence of each hardening parameter on the macroscopic mechanical response and twin activation and evolution is studied. According to the different deformation processes, the deformation process can be divided into the twin hardening stage and the twin hardening failure stage, The procedure of determining the hardening parameter and the range of its recommended value are given.The results show that the initial slip resistance is linearly correlated with the yield limit, and the range is between 80 MPa and 160 MPa. The increase of the twinning hardening index weakens the twin hardening phase , Its value should be in the range of 0 to 3; twin resistance and slip resistance ratio increases, the twin growth rate decreases, the hardening rate of inflection point after the shift until Inflection point disappears, its value in the range of 1 to 1.3.