【摘要】 基于对NiTi形状记忆合金的实验观察及有限元分析,考虑两相间的应变不协调关系,采用应变修正法建立了计及片层状微结构的本构模型,本模型考虑了两相间的相互约束,及其约束随微结构演化的变化规律.研究了NiTi形状记忆合金微圆管在拉伸和扭转下的响应特性.计算结果与实验结果的对比表明所建本构模型较好地描述了伪弹性响应尤其是较好地描述了拉伸实验过程中的应力跌落现象.更多还原

【Abstract】 Based on the experimental results and the finite element analysis,and taking into account laminar microstructure,the thickness of martenite phase and the interaction between the two phases,the incremental form of the constitutive model is proposed for two-phase shape memory alloys using the modified strain method.The pseudoelastisity of NiTi shape memory alloy microtube subjected to pure tension or pure torsion are analyzed and compared with the experimental results.It can be seen that the pseudoelastic behavior,especially the phenomena of a stress drop during tension processes can be well described with the proposed model.更多还原