细观力学法预测单向复合材料的有效热膨胀系数

Predicting macroscopic thermal expansion coefficient of unidirectional composite material by micro-mechanics

基于细观力学方法建立了两种预测单向复合材料的热膨胀系数的方法。以单向复合材料为研究对象,从理论上推导了单向复合材料的热膨胀系数公式,并运用通用有限元软件Msc.PATRAN/NAST RAN建立RVE模型,模拟热传导过程进行有限元计算。两种方法计算的结果与实验均有较好的一致性。

Two methods are established to predict the thermal expansion coefficient of Unidirectional composite based on micro-mechanics. One is established by the mathematical equation of the thermal expansion coefficient of Unidirectional composite. If the elastic moduli and thermal expansion coefficient of each constituent phase is known under the certain temperature, the equation can predict the thermal expansion coefficient without the need to consider the thermal stress. The other is developed based on micro-mechanics finite element method. Finite element Software Msc.PATRAN / NASTRAN is used to stimulate the thermal environment of RVE model in order to obtain the thermal stress for computing thermal expansion coefficient. And then contrasting the results of these two methods with experimental value. As an example, thermal stress is obtained through heat conduction for computing thermal expansion coefficient.