Measurements of Thermal Properties of Carbon/Epoxy and Glass/Epoxy using Modulated Temperature Differential Scanning Calorimetry

Abstract

Major potential of composite materials relies in the nonlinear behavior triggered by their inhomogeneous nature. Particularly in heat diffusion, composite materials present a high variation of thermal properties as a function of temperature. Therefore, the spectrum of a propagating thermal wave can contain higher harmonics of the excitation frequency. The amplitude of these harmonics depends on the range of temperatures developed inside the material. This study is focused on the mathematical formulation of the relationship between thermal properties and temperature. To this end, the heat capacity and the thermal conductivity of Carbon/Epoxy and Glass/Epoxy cross-ply laminates were determined in a temperature range of interest for the aircraft industry using an ASTM method based on Modulated Temperature Differential Scanning Calorimetry. The results are indispensable toward a nonlinear treatment of heat diffusion phenomena and the respective exploitation for nondestructive testing.