SMA驱动丝的建模与仿真

研究SMA动力学优化模型,针对形状记忆合金(SMA)驱动丝具有强非线性、迟滞效应等特性,为设计SMA驱动丝的自适应结构,提出建立SMA驱动丝模型并提供高效的仿真方法。采用有限元软件实现了受轴向载荷的SMA驱动丝的仿真建模。对本构模型是根据自由能的一维热-力学耦合模型,可以同时复现形状记忆效应和超弹性。数值仿真能够引起材料相变的非均匀温度和应变分布。仿真结果表明,建立热-力学耦合模型,可为设计SMA驱动丝的自适应结构计算提供可靠依据。

Modeling and Simulation of SMA Wire Actuator

Shape memory alloy(SMA) shows high nonlinear and hysteretic phenomenon.In order to design SMA based adaptive structure,it is necessary to model and simulate the wire actuator in an efficient way.A thermo-mechanical model of SMA wire under uniaxial loading was implemented in finite element codes.The constitutive model is a one dimensional model which based on free energy and motivated by statistical thermodynamics.The model has the ability to represent both shape memory effect and pseudoelasticity.The numerical simulations can capture the inhomogeneous thermal and strain distribution which triggers the phase transformation locally.After investigation under different convective boundary conditions,the result shows that an obvious stroke lost happened in fixed temperature case comparing with adiabatic thermal boundary conditions which come from the thermo-mechanical coupling effect.