NiTi形状记忆合金纤维拔出中的力学问题

Mechanical behavior in the pull-out process of NiTi SMA fiber

对NiTi形状记忆合金纤维拔出的力学模型进行了探讨。在恒温状态下,考虑纤维和基体间的界面摩擦力,分别用两种本构理论,即Tanaka的指数模型和C.Liang的余弦模型,讨论了形状记忆合金纤维在变轴力作用下的拉伸问题。推导了形状记忆合金纤维拔出量的表达式,并给出数值计算结果。由指数模型和余弦模型得到的结果非常吻合,证明了这种理论方法是正确的。

This article discusses the pull-out mechanical model of NiTi shape memory alloy（SMA） fiber. In constant temperature state, considering the interfacial friction between the fiber and matrix, the tensile problem of SMA fiber under varying axial force is discussed, and the formulation of memory alloy fiber＇s pull-out length is obtained by two theories respectively, namely the index model of Tanaka and the cosine model of C. Liang. The numerical results are given. The good agreement between the results of index model and cosine model warrants this new theoretical method.