中文摘要：

利用形状记忆因子的概念,建立了用于描述纯剪切状态下形状记忆合金（SMA）相变行为的形状记忆演化方程.在假设SMA为各向同性材料和利用三维细观力学本构方程的前提下,推导了纯剪切状态下SMA的力学本构方程.所建立的形状记忆演化方程和力学本构方程中的材料常数均可以通过宏观实验来测定,便于工程实际中的应用.数值计算结果表明,所建立的形状记忆演化方程能正确地描述纯剪切状态下SMA发生在奥氏体、孪晶马氏体和非孪晶马氏体间的相变行为,力学本构方程可再现形状记忆效应和超弹性的热力学过程.

英文摘要：

It is of engineering interest to establish a constitutive model which includes the equations describing the phase transformation and mechanical behaviors of shape memory alloys（SMA） in pure shear state.In this study,such a shape memory evolution equation is established using the shape memory factor and Brinson＇s relationship of phase transformation critical stress and temperature. A mechanical constitutive equation is also developed from 3D micro mechanical constitutive equation based on the assumption that SMA is isotropic material to express the mechanical behaviors of SMA in pure shear state.All material constants in the shape memory evolution equation and mechanical constitutive equation can be determined through macroscopic experiments,so that they are more easily used in practical applications.Numerical simulation results show that this shape memory evolution equation could simulate truly the processes of phase transformations in austenite,twinned and detwinned martensites,and the mechanical constitutive equation could predict reasonably the mechanical behaviors of SMA in pure shear state.