计及相变与塑性的NiTi形状记忆合金循环伪弹性特性描述

A Constitutive Description of Cyclic Pseudoelasticity for the NiTi SMAs Involving Coupled Phase Transformation and Plasticity

结合NiTi形状记忆合金单轴循环变形试验研究结果,采用基于混合物理论的计及相变、重取向与塑性变形的形状记忆合金本构模型发展了相应的算法和程序.对NiTi形状记忆合金单轴循环变形行为进行了描述.通过试验结果与模拟结果的比较,验证了本构模型与算法的有效性.

According to the main experimental constitutive characteristics of the NiTi shape memory alloys（ SMAs） subjected to cyclic tensile loading,and in line with the constitutive relationship for the SMAs,an analytical approach and the corresponding numerical algorithm as well as the computational program were developed. The constitutive description is based on the mixture theory,employs the Voigt hypothesis,and takes into account the effects of forward and inverse martensitic transformation,reorientation deformation and plastic deformation. The pseudoelastic behavior of a NiTi SMA subjected to cyclic tensile loading and unloading was simulated. The comparison between the computed and experimental results shows that the main characteristics of the material under cyclic loading can be satisfactorily described,which demonstrates the validity of the constitutive model and the developed numerical program.