ANALYSIS OF THERMALLY-INDUCED STRESS AND STRAIN IN CONTINUOUS FIBER-REINFORCED COMPOSITES

An axisymmetric model for the thermally induced stresses and strains in a deformable matrix continuous fiber-reinforced composite is developed. The model allows for a temperature- and strain-dependent matrix flow stress and is numerically implemented using a von Mises flow law. The model implementation permits the study of an arbitrary number of temperature cycles. This model is compared to a simple one-dimensional model that has been used in several previous analyses. The models show good qualitative agreement, but there are important differences, and the magnitude of the discrepancy depends sensitively on the properties of the composite. These models can be applied in analyzing experimentally measured strain vs temperature hysteresis loops to reveal the in situ mechanical properties of the deformable matrix. The models can also be applied to the design of continuous fiber-reinforced composites that will not suffer thermally induced cyclic-plastic deformation.