Prediction of the thermal conductivity of the constituents of fiber reinforced composite laminates

Abstract

Three empirical formulas are developed to predict the thermal conductivities of fiber-reinforced composite laminates (FRCL) and its constituents. The inherent two or three-dimensional problem that is common in composites is simplified to a one-dimensional problem. The validity of the models is verified through finite element analysis. This method utilizes the parallel and series thermal models of composite walls. The models are tested at different fiber-to-resin volume ratios (30:70–75:25) and various fiber-to-resin thermal conductivity ratios (0.2–5). The predicted thermal conductivity of the fiber can be accurately predicted throughout the spectrum via two models. The first model is a first-order formula (R 2 = 0.94) while the second model is a second-order formula (R 2 = 0.976). These two models can be used to predict the fiber thermal conductivity based on the easily measured resin and laminate values. A third model to predict the overall laminate thermal conductivity is introduced. The thermal conductivity of the composite panel is predicted with very high accuracy (R 2 = 0.995). The thermal conductivity predicted via the use of these models has an excellent agreement with the experimental measurements. Another use of these models is to determine the fiber-to-resin volume ratio (if all thermal conductivities of fiber, resin and laminate are known).