数値解析による座屈後Cu系形状記憶合金の力学特性に関する研究

抄録

The purpose of this study is to investigate numerically the static and dynamic characteristics of a copper based shape memory alloy (SMA). In the previous study, we have proposed a vibration isolator using a Ti-Ni based post-buckled shape memory alloy to improve the isolation performance utilizing the negative tangent stiffness of post-buckled SMA and to mitigate the design requirement for the isolator. However, some inconvenient characteristics had been proved when Ti-Ni based SMA was applied to an isolator. Therefore, in this study, in order to overcome these inconvenient characteristics, we investigate the dynamic properties of a copper based SMA. Firstly, the static restoring force of post-buckled Cu based SMA was investigated. From the numerical result, the negative tangent stiffness of post-buckled SMA was stably observed and it was confirmed that the negative tangent stiffness arises when the phase transformation from austenite phase to martensite phase begins. Subsequently, the dynamic response of SMA was investigated. From this numerical result, it was confirmed that dynamically loaded SMA has good structural attenuation characteristics. In addition, the frequency response results showed that Cu based SMA has a reduction in the primary natural frequency and resonance peak compared to linear material.