SMA增强复合材料力学特性的细观力学模型.pdfVIP

复 舍 材 抖 学报 第 25卷 第 2期 4月 2008年 ∞ Vo1．25 No．2 April 2OO8 文章编号：1000-3851(2008)02—0156—05 SMA增强复合材料力学特性的细观力学模型 朱玉萍 ，兑关锁 (北京交通大学工程力学研究所，北京100044) 摘 要： 基于细观力学的理论，将SMA增强复合材料视为三相等效系统进行分析，即基体相、奥氏体相和马氏 体相；求解了SMA增强复合材料的有效热膨胀系数和有效相变应变系数的一般表达式，该表达式适用于各种形 状的纤维增强复合材料。在整个相变和逆相变过程中，奥氏体相和马氏体相都表现为弹性特性，避免了传统方法 的强非线性问题。该模型计算过程简单，同时还考虑了奥氏体、马氏体和基体间的相互作用，理论分析更接近实 际。并分析了纤维的含量、形状和尺寸等因素对宏观模量的影响，通过比较可知，所得结果可靠，为SMA增强复 合材料的设计和使用提供理论依据。 关键词： 形状记忆合金；复合材料；热膨胀系数；相变应变系数；细观力学 中图分类号： TB330．1；TB381 文献标志码：A Micromechanical modeling of mechanical property for SMA reinforced composite ZHU Yuping ，DUI Guansuo (Institute of Mechanics，Beijing Jiaotong University，Beijing 100044，China) Abstract： A three—phase model for the thermal expansion coefficient and transformation strain coefficient of the shape memory alloy composite was developed，in which the composite was considered as the austenitic phase，the product phase(martensite phase)and the matrix phase． The common expressions for the thermal expansion coefficient and transformation strain coefficient of the shape memory alloy composite were derived based on the micromechanical analysis．The expressions can be fit for fibers with various shapes．Compared with the traditional method，non—linearity of shape memory alloy need not be considered．Not only was the method simple，but also the interaction among the three phases was considered．As an application of the model，the attention was paid tO the effects of the fiber geometry，various shapes and volume ratio of fibers in the composite on the effective thermal expansion coefficient and transformation strain coefficient of the composite．By comparing with