基于频率效应的超弹性形状记忆合金本构模型

FREQUENCY DEPENDENT CONSTITUTIVE MODEL FOR SUPERELASTIC SHAPE MEMORY ALLOY FOR APPLICATION IN ENGINEERING

  • 摘要: 超弹性形状记忆合金(SMA)的力学特性受荷载频率影响较大。在Lagoudas多线性一维本构模型基础上,仔细分析了SMA在不同频率荷载下的试验资料,提出应力-温度相图中四组相变应力直线的斜率随荷载频率变化以及最大残余应变与频率负相关的假定,建立了基于频率效应的SMA线性本构模型。对不同频率下SMA的应 力-应变曲线进行数值模拟,表明该模型能较准确地模拟SMA在不同荷载频率下的滞回主环力学特性,但预测的子环与试验误差稍大。采用荷载频率为0.003Hz和0.08Hz时SMA本构模型,分别计算了SMA-弹簧-振子在不同频率正弦激励下的振动响应,表明SMA单元能够有效实现结构的被动控制,并在一定程度上反映了由于SMA模型不同而带来的控制效果的差异。

     

    Abstract: The mechanical behaviors of super-elastic shape memory alloy (SMA) are frequency-dependent. Based on Lagoudas’ multilinear one-dimensional model, some hypotheses are put forward by analyzing SMA’s testing data. That is, the slopes of the four phase transformation lines in the phase transformation diagram are frequency-dependent parameters, and the maximum residual strain is negative frequency-dependent. A frequency-dependent SMA constitutive model is presented. Some numerical simulations show that the simulated major loops agree well with the experimental results, but a little more differences can be seen between the simulated and experimental sub-loops. The proposed model at 0.003Hz and 0.08Hz is used to examine the dynamic responses of a SMA-spring-mass subjected to harmonic cyclic loading with different frequencies. Results show that SMA element can reduce the mass’ vibration response effectively, and that the difference between the controlled mass’ vibration response resulting from the diverse SMA’s models is valued to some extent.

     

/

返回文章
返回