弹头冲击形状记忆合金悬臂梁实验的数值模拟

借助有限元软件ANSYS-LSDYNA,对弹头冲击伪弹性TiNi形状记忆合金(SMA)悬臂梁的实验进行了数值模拟研究。结果表明,计算所采用的SMA本构抓住了梁冲击响应的主要特征,较好地再现了实验中高速摄影机记录到的梁的运动过程以及应变片测得的波形;根据计算结果揭示了相变弯曲波的传播以及与自由端反射波相互作用的过程中相变区的时空演化规律,分析了相变铰的可回复与有限性两个特性及其对结构响应的影响,并提出了TiNi梁能量耗散的机制。

Numerical Simulation of the Experiment on a Shape Memory Alloy Cantilever Impacted by a Bullet

A numerical simulation of the experiment on a TiNi shape memory alloy (SMA ) cantilever at the pseudo elastic state impacted by a bullet was investigated by using the FEA software ANSYS-LSDYNA. The result showed that the SMA model adopted in the simulation captured the main characteristic of the cantilever impact response. The simulation reproduced well the movement and deformation of the cantilever and the wave profile in the experiment which were recorded by the high speed camera and measured by the strain gauges respectively. On the basis of the comparison between simulation and experiment, the impact response of the SMA cantilever was revealed in detail. Firstly, the spatio-temporal evolution regularity of the transformation zones was revealed when the transformation flexural wave propagates and interacts with its reflected wave from the free end. Then the typical recoverable and finite characteristics of a transformation hinge and its effect on the structure response were further analyzed. Finally the energy dissipation mechanism of TiNi cantilever was represented.