Electromagneto-thermo-mechanical Dynamics of Composite SMA System

本研究旨在探讨形状记忆合金（SMA）板及SMA复合材料的电磁-热-机械特性。(1)通过拉伸、加热和振动试验，研究了形状记忆合金板的磁热机械特性：（1）马氏体相变和奥氏体相变TiNi板的本构方程可以用形状记忆合金丝的本构方程来描述;（2）形状记忆合金板可以通过非接触式电磁感应加热。通过电磁感应加热可以改变形状记忆合金板的固有频率。(2)将钛镍形状记忆合金的可逆形状记忆效应（RSME）应用于流体流动控制。随着温度的升高，形状记忆合金板的形状由扁平变为弧形，这种形状记忆合金板的形状变化是由R相变引起的，因此与马氏体相变相比，其滞后性较小。该流体流动控制器可以将热流体和冷流体分离到每个对应的出口。该流体控制器中的SMA板致动器可以在没有传感器和偏置弹簧的情况下移动。(3)SMA纤维包埋在丙烯酸树脂中。这种复合材料板的固有频率随温度的升高而改变。虽然基体的刚度随温度的升高而降低，但通过SMA纤维的变形，复合材料板的总刚度几乎保持不变。

The purpose of this study is to investigate the electromagneto-thermo-mechanical properties of Shape Memory Alloy (SMA) plates and SMA composites.(1) Tensile, heating and vibration tests were performed for the evaluation of the magneto-thermo-mechanical characteristics of a SMA plate.i) The martensite transformation and austenite transformation TiNi plates can be expressed by the constitutive equations which have been originally derived for SMA wires.ii) SMA plate can be heated by the noncontact electromagnetic induction. The natural frequency of a SMA plate can be changed by the electromagnetic induction heating.(2) Reversible shape memory effects (RSME) of Titanium-Nickel SMA was applied to fluid flow control. The SMA plate changes its shape from flat to arc with temperature rise by RSME.The shape change of this SMA plate is caused by R-phase transformation, hence it has small hysterisis compared with martensite transformation. This fluid flow controller can separate hot fluid and cold fluid to each corresponding outlet. The SMA plate actuator in this fluid controller can move without sensors and bias springs.(3) SMA fibers were embedded in Acryl resin. This fabricated composite plate can change its natural frequency by temperature rise. Though the stiffness of matrix decreases as temperature rises, the total stiffness of the composite plate can be kept almost constant by using the transformation of SMA fibers.