Influence on Effective Thermal Conductivity

The temperature-dependent thermal conductivity was estimated by the inverse rule of mixture with reference to the physical series model. Again the volume fraction of each phase (undecomposed and decomposed) was directly obtained from the decomposition model and mass transfer model. The rapid decrease of thermal conductivity during the decomposition process was also well described in this way in the modeling of effective thermal conductivity. The modeling approach was compared with previous models and validated by experiments using the hot disk method. 

The true specific heat capacity of a composite material was obtained by the mle of mixture and the mass fraction of each phase was determined by the decomposition and mass transfer model. The true specific heat capacity of resin or fiber was derived based on the Einstein or Debye model. The effective specific heat capacity was obtained by assembhng the trae specific heat capacity with the decomposition heat that was also described by the decomposition model. The modeling approach for effective specific heat capacity is useful in capturing the endothermic decomposition of resin and was further verified by a comparison to DSC curves. 

Henderson, J.B., Wiebelt, ).A., and Tant, M.R. (1985) A model for the thermal response of polymer composite materials with experimental verification. J. Compos. Mater., 19, 579-595. 

Henderson, J.B. and Wiecek, T.E. (1987) A mathematical model to predict the thermal response of decomposing, expanding polymer composites. /. Compos. Mater., 21, 373-93. 

Samanta, A., Looyeh, M.R.E., Jihan, S., and McConnachie, J. (2004) Thermo-Mechanical Assessment of Polymer Composites Subjected to Fire, Engineering and Physical Science Research Council and the Robert Gordon University, Aberdeen. 

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