Prediction of Coefficients of Thermal Expansion for Unidirectional Composites

Abstract

Several analyses for predicting the longitudinal, α₁, and transverse, α₂, coefficients of thermal expansion of unidirectional composites were compared with each other, and with experimental data on different graphite fiber reinforced resin, metal, and ceramic matrix composites. Analytical and numerical analyses that accurately accounted for Poisson re straining effects in the transverse direction were in consistently better agreement with ex perimental data for α₂ than the less rigorous analyses. All of the analyses predicted similar values of α₁, and were in good agreement with the experimental data. A sensitivity analysis was conducted to determine the relative influence of constituent properties on the predicted values of α₁ and α₂. As would be expected, the prediction of α₁ was most sensi tive to longitudinal fiber properties and the prediction of α₂ was most sensitive to matrix properties.