TiNi形状记忆合金弹性耦合系统的驱动特性

采用将预应变TiNi合金与不同刚度系数k的偏置弹簧相串联的方法,对TiNi合金弹性耦合系统的驱动特性进行了研究。结果表明,随k值的增加,TiNi样品达到逆相变结束时的输出应变、应力温度范围逐渐变大,最大回复力逐渐增大,但驱动行程减小;样品的应力与应变之间呈线性关系,二者的比值取决于k;预应变量较大的样品,其回复应力随温度的变化率较大。通过配置偏置弹簧的刚度系数,可以控制样品输出的最大应力和最小应变,有效防止耦合系统过载。

Actuation characteristics of elastic couplings with different bias springs on TiNi shape memory alloys

The actuation characteristics of elastic couplings with different bias springs on prestrained TiNi shape memory alloys were systemically studied. The results show that the recovery strain and stress temperature ranges of TiNi samples are widened along with stiffness coefficient increasing. The maximum recovery stress increased gradually, but the stroke of the TiNi actuator reduced when stiffness coefficient increasing. The relationship between the output stress and the strain of the TiNi sample is linear. The ratio of the stress and strain rests with the stiffness coefficient. The larger the prestrain degree is, the larger the recovery stress rate of change with temperature changing is. Choosing an appropriate bias spring can control the maximum stress and the minimum strain of the TiNi sample. This characteristic is effective to prevent the coupling system from overloading.