Electromagneto-thermo-mechanical Dynamics of Composite SMA System

本研究的目的是研究形状记忆合金（SMA）板及其复合材料的电磁热机械性能。(1)通过拉伸、加热和振动试验对SMA板的磁-热-机械特性进行评价。i)马氏体转变和奥氏体转变可以用最初为SMA丝导出的本构方程来表示。ii) SMA板可以通过非接触电磁感应加热。通过电磁感应加热可以改变SMA板的固有频率。(2)将钛镍SMA的可逆形状记忆效应（RSME）应用于流体流动控制。通过RSME， SMA板的形状随着温度的升高由扁平变为圆弧。该SMA板的形状变化是由r相相变引起的，因此与马氏体相变相比具有较小的迟滞性。该流体流量控制器可以将热流体和冷流体分离到每个相应的出口。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)将SMA纤维包埋在丙烯酸树脂中。该复合板可以通过升温改变其固有频率。虽然基体刚度随温度升高而降低，但通过SMA纤维的转化，复合材料板的总刚度基本保持不变。

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.