【摘要】 形状记忆合金是由马氏体和奥氏体组成并动态变化的两相材料 ,其拟弹性行为实质上是两相各自行为的动态组合。本文提出了形状记忆合金拟弹性行为的一种热力学描述。根据实验现象假设在感兴趣的温度和变形范围内 ,奥氏体相具有线弹性特性而马氏体相具有弹塑性特性 ,结合 Tanaka的相变描述 ,给出了小变形、初始各向同性和塑性不可压缩条件下形状记忆合金的三维本构方程。对不同温度下形状记忆合金材料的特性进行了描述 ,较好地预言了单调及循环加载下的响应和正、反相变行为及其温度影响 ,动态相变过程对应力响应的影响 ,高温相下的强度增加等。更多还原

【Abstract】 Shape memory alloys (SMA) are dynamically composed of austenite and martensite. The pseudoelasticity of SMA can be regarded as the dynamic combination of the individual behavior of each phase. Based on this understanding, a constitutive model is proposed for SMA, in which, the behavior of austenite is further assumed to be linearly elastic while that of martensite elastoplastic. The behavior of SMA under different temperature is described and the main fundamental properties of SMA are qualitatively and quantitatively reproduced. The proposed constitutive model is simple, physically distinct and can easily be applied to the analysis of practical engineering problems.更多还原