1142 繊維クラスタを有する短繊維複合材料の熱膨張係数のマイクロメカニックス解析(G03-3 材料力学(3)複合材料1,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

Abstract

A Material, which has zero or a very small thermal expansion coefficient, is expected in parts for precision machines and electronic devices. An analytical model is developed to evaluste effects of fiber clusters on thermal expansion coefficients of a short fiber composite by applying the Eshelby's equivalent inclusion method to two kinds of inhomogeneities, i.e. fiber and cluster. It is assumed that the fibers and clusters distribute uniformly within the limits of an arbitrary orientation angle in the 2-D plane. A carbon fiber/epoxy resin composite is estimated. The carbon fiber has a negative thermal expansion coefficient in the longitudinal direction. The possibility of realizing very small thermal expansion coefficients in the short fiber composite is shown. And it is indicated that the thermal expansion coefficient increases as the volume fraction of clusters increases.