Abstract:

The SMA torsion drive designed herein is based on the flexible structure. It realized its torsion output through the deformation of flexible structure which was caused by heating the SMA wire. As the deformation had a great influence on the torsion angle output, it was needed to optimize the shape of flexible structure and the load point. This paper adopted a cubic B-spline curve to describe the shape of the flexible structure, analyzed the transformation of the flexible structure by finite element method and optimized the shape of flexible structure by genetic algorithm. Through practical examples, it is shown that the shape of the flexible structure obtained by this method makes the SMA torsion drive output a maximal torsion angle.

Key words: torsion actuator, flexible structure, shape memory alloys(SMA), shape optimization, genetic algorithm

摘要：

设计了一种基于柔性结构的SMA扭转驱动器，通过加热SMA丝收缩带动柔性结构变形从而实现驱动器的扭转输出。柔性结构在SMA丝拉力作用下的变形情况对驱动器的转角输出有很大的影响，为获得最大的输出转角，需对柔性结构的形状和SMA丝的作用点位置进行优化设计。采用三次B样条曲线描述柔性结构的形状，通过有限元法分析柔性结构的变形，并应用遗传算法进行柔性结构的形状优化和SMA丝作用点位置优化。实际算例表明，利用优化方法可快速有效地获得使SMA柔性扭转驱动器输出转角最大的柔性结构形状与SMA丝作用点位置。
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关键词: 扭转驱动器, 柔性结构, 形状记忆合金, 形状优化, 遗传算法