THERMAL-EXPANSION BEHAVIOR OF SKELETONIZED 3D-COMPOSITES

In a recent paper, the authors have pointed out that the coefficients of thermal expansion (CTEs) of composites can be reduced by mixing mic rovoids in the matrix. In this paper, this principle was applied to 3D fabric composites (3DFCs). Three kinds of multiaxially reinforced 3DF C were formed into a porous (skeletonized) structure and the CTEs of t hese composites were measured. It was found that the CTEs of the compo sites were drastically reduced by introducing voids. Thus, by utilizin g this technique, we can control the CTE of 3D composites in the range from the value of a usual 3D composite completely filled with the mat rix, to nearly 0. These CTE values of skeletonized composites were sho wn to agree reasonably well with the analytical predictions based on t he Eshelby's equivalent inclusion method.