【摘要】 以弹性变形梯度作为基本变量,结合热力学理论构造了单晶有限变形的热、力耦合计算模型。该模型考虑了温度、变温速率以及塑性耗散等条件对单晶有限变形的影响,相对于传统的以弹性变形梯度为基本变量的晶体塑性模型,算法能够体现温度效应的影响。采用隐式的积分方法对建立的控制方程进行计算以保证求解过程的稳定。以1100Al单晶为例计算了不同升温、降温速率,以及不同应变率影响下的材料应力-应变的响应。结果表明,模型能较好地反映变温过程中,单晶各向异性性质的演化以及应力、应变之间关系的变化。更多还原

【Abstract】 A thermo-mechanical coupled model based on thermodynamic theory is presented.The elastic deformation gradient was chosen as the basic integration variable in this model.The effects of temperature,temperature changing rate and dissipation of plastic deformation are considered in the finite deformation computation.Compared to the traditional algorithm with the elastic deformation gradient as its basic variable,this model can reveal the thermal effects.An implicit integration method was chosen to ensure the numerical stability.The effects of different heating/cooling rates and strain rates on stressstrain response of 1100 Al single crystal are computed.The results showed that this model can evaluate the variation of anisotropy and stress-strain response for single crystal deformation with changing temperature.更多还原