循环加载条件下形状记忆合金丝的超弹性研究

由于形状记忆合金具有优良的力学性能,近年来在土木工程领域受到广泛关注.通过在不同的循环加载条件下对形状记忆合金丝材进行的拉伸试验,以相变应力、相变应变、弹性模量、残余应变、耗能能力等作为合金丝材的超弹性特征参数,分析这些特征参数与应变幅值、加载频率、循环次数的关系.结果表明：应变幅值和循环次数对形状记忆合金超弹性性能的影响较大,而加载频率的影响基本可以忽略,实际应用时,应根据具体情况进行试验研究并合理设计.

Study on Superelasticity of Shape Memory Alloy Wire Under Cyclic Loading Conditions

As it has excellent mechanical properties,the shape memory alloy has been widely concerned in civil engineering field in recent years.Through the tensile test of the shape memory alloy wires under different cyclic loading conditions,this paper analyzes the relationship between these parameters and the strain amplitude,loading frequency and cycle numbers,taking the phase transformation stress,phase transformation strain,elastic module,residual strain and capacity of dissipated energy as superelastic characteristic parameters.The results indicate that the strain amplitude and cycle numbers have great influence on the superelasticity of the SMA,but the influence of loading frequency can be neglected in the main.So we should carry out experimental studies and reasonable designs according to the specific circumstances in practical applications.