SMA复合材料在热载条件下的残余应力分析

An Analysis of Residual and Transformational Stresses in SMA Composites

本文基于三相复合圆柱模型发展了增量型的分析方法,讨论在SMA复合材料中由于SMA材料相变以及各相材料热特性随温度变化引起的残余应力。研究基体与过渡层界面和纤维与过渡层界面间的残余应力,同时讨论由于基体相的变化对残余应力的影响。特别研究了涂层和复合材料基体间界面处的残余应力受纤维体积比、涂层厚度、纤维最大相变应变以及基体中纤维取向等的影响,而且讨论了计及应力对相变运动方程的影响时对SMA复合材料相变温度和残余应力的影响。这些工作对于指导材料设计是有意义的。

In this paper, the residual stresses generated due to the difference in the thermal expansion and transformational stresses due to the SMA transformations from martensite to austenite or the reverse course are disscused on the basis of the devolped incremental three-phase micromechanical model. These stresses acting in combination can lead to SMA/matrix interfacial debonding or microcracking of the composite phase. Special attentions are paid to investigate the stresses acting in the coating/matrix interface when considering the effects of the SMA volume, the maximum residual transformational strain and the coating thickness, etc. Meanwhile, the residual stresses and the transformational temperature when considering the influence of stress on the transformational kinetic law are disscused. Some valuable results are obtained and can be used to direct the design of SMA composites.