形状记忆合金弹簧力学性能分析

利用直杆的扭转理论对形状记忆合金密圈螺旋弹簧的力学性能进行了理论分析,给出了弹簧加载力和变形量的全程非线形力与变形关系,特别是形状记忆合金相变过程对弹簧刚度的影响.虽然形状记忆合金材料的相变本构为简单的三线性平台型模型,在加卸载过程中,相变区和相变体积分数随载

Analysis on the Mechanics Peoperties of Shape Memory Alloy Spring

Based on torsion theory of straight god, the mechanical properties of shape memory alloy close-coil spring are shown. The nonlinear relation between the loading force and deformation, stiffness of spring and martensite transformation in spring can be illustrated. Although the constitutive model of shape memory alloy is three linear and plateau, the stiffness of spring changes nonlinearly because transformation domain and transformation volumetric fraction will be related to load. When load increases, transformation first occurs on surface and extends inward, but transformation area cannot expand to all section. In the process of unloading, reverse transformation begins in the middle part of section and extends inward and outward.