形状记忆合金的二维本构模型

A Two-phase Constitutive Model for Shape Memory Alloys

形状记忆合金(Shape Memory Alloy,简称SMA)的二维本构模型是在SMA由奥氏体和马氏体动态组成的基础上建立起来的.在一定的应力与温度范围内,由于马氏体是弹塑性的,则把奥氏体的行为假设为线弹性的,SMA行为被认为是每一相单独行为的动态组合.利用传统的塑性理论提出了SMA的二维本构模型,此模型可以用来描述SMA的主要特征,如铁弹性、形状记忆效应和伪弹性等,计算结果比较符合实验结果.

A two-phase constitutive model for shape memory alloys （SMAs） is proposed based on the fact that SMAs is dynamically composed of austenite and martensite, and using the conventional theory of plasticity. In the interested ranges of stress and temperature, the behavior of austenite is assumed to be linearly elastic while that of martensite elastoplastic, and the behavior of SMAs is regarded as the dynamic combination of the individual behavior of each phase. This model can describe the main characteristics of SMAs, such as ferroelasticity at lower temperature, shape memory effect, and pseudoelasticity at high temperature. The increase of critical stress with the increase of temperature can also be well described. The corresponding numerical algorithm was also developed, the main features of shape memory alloy Au-47 .Sat. %Cd are satisfactorily replicated, which demonstrates the validity of the proposed constitutive description.