Determination of Thermal Conductivity of Polymer Composites Filled with Solid Glass Beads

Abstract

A numerical simulation of the heat-transfer process within epoxy matrix composites filled with solid glass beads (SGB) is made by using finite element analysis (FEA). A commercially available finite-element package ANSYS is used for this numerical analysis. Three-dimensional spheres-in-cube lattice array models are constructed to simulate the microstructure of composite materials for various SGB content ranging from about 1 to 18 vol % and the effective thermal conductivities (Keff) of the composites are estimated. The results show that the FEA simulated effective thermal conductivity decreases almost in a parabolic manner with increase in the volume fraction of the SGB fillers in the composites. Finally, the simulations are compared with measured Keff values obtained from experiments. Guarded heat flow meter test method is used employing the instrument Unitherm™ Model 2022 as per ASTM-E1530 to measure the thermal conductivity of these composites fabricated by hand layup technique. This study shows that the incorporation of SGB results in reduction of heat conductivity of epoxy resin and thereby improves its thermal insulation capability. The experimentally measured conductivity values are compared with the numerically calculated ones and it is found that FEA simulations are fairly close to the measured Keff.