Method to Measure Thermal Diffusivity Coefficients of 2 Dimensions for Carbon Fiber Reinforced Carbon Composites by Use of Light Heating

Abstract

Carbon fiber reinforced carbon composites (C/C composites) have been important structural materials at high temperatures. C/C composites are anisotropic solids and their thermal diffusivity is 2nd-order tensor of which components are called thermal diffusivity coefficients. The objective of study is to evaluate thermal diffusivity coefficients for an anisotropic material of which diad axes (such that a rotation of 180 degrees about them brings the structure into a position congruous with its original one) are unknown using stepwise light heating method in which the finite element method (FEM) is used for data reduction. This report describes experiments conducted to confirm a principle for the anisotropic material at room temperature and thermal diffusivity coefficients measured for metals and C/C composites which are cut from a plate at some angles with the direction of fiber.