复合材料热膨胀性能的细观分析模型与预报

Prediction of thermal expansion properties for composites by micromechanical analysis model

基于细观力学有限元方法对T300/5208,P75/934,P75/CE339,C6000/PMR15,HMS/Borosilicate,P100/2024 Al六种复合材料的纵向和横向热膨胀系数进行了预报,并将预报结果与国内外常用的几种理论方法的预报结果以及试验值进行了对比,分析了各分析方法的预报精度.各分析方法对于复合材料的纵向热膨胀系数的预报结果与试验值均能很好吻合;对于横向热膨胀系数,各分析方法的预报结果相差较大.Rosen and Hashin(RH)方法与所建立的细观力学有限元分析模型的预报结果与试验值的吻合程度比其他理论方法要高,进而验证了细观力学有限元方法的可靠性.此外,基于细观力学有限元方法建立了各种材料体系热膨胀系数对纤维体积分数的响应关系,得出复合材料纤维/基体性能比对其热膨胀系数的影响,为航空航天结构先进复合材料的应用提供了技术基础支撑.

A micromechanics finite element method was used to predict the longitudinal and transverse coefficients of thermal expansion of the following six kinds of composites, T300/5208, P75/934, P75/ CE339, C6000/PMR 15, HMS/Borosilicate, P100/2024 A1. The predictions and some other common analyti- cal methods were compared with each other. With experimental data, the predicting accuracy of all these anal- ysis methods was investigated. In all of these methods, the predictions for the longitudinal coefficients of ther- mal expansion of composites have good agreement with experimental values. However, large discrepancies ex- ist for the transverse coefficients of thermal expansion. The predictions of the Rosen and Hashin（RH） method and micromechanical finite element analysis model are better fit for the experimental values than other analyti- cal methods, and then verify the reliability of the micromechanics finite element method. In addition, the re- sponse of the coefficients of thermal expansion for the fiber volume fraction of the six kinds of composites was established by using micromechanics finite element method, the influence of the property ratios of fiber and matrix on the coefficients of thermal expansion was obtained. The results provide the technical foundation for the application of advanced composite materials in aerospace structures.