Temperature dependent longitudinal tensile strength model of unidirectional fiber reinforced polymer composites considering the effect of matrix plasticity

The unidirectional fiber reinforced polymer (FRP) composites have captured intensive attention of scholars owing to their superior longitudinal tensile properties. In this work, a temperature dependent longitudinal tensile strength model for unidirectional FRP composites was established based on the Force-Heat Equivalence Energy Density Principle and the bridging model. The model considers the evolution of constituents' properties and residual thermal stress with temperature. Especially, the effect of polymer matrix plasticity at different temperatures on the temperature dependent tensile strength of unidirectional FRP composites is considered. Compared with our previous model and the Curtin's model, the model can more conveniently predict the temperature dependent tensile strength, and the predictions obtain a better agreement with the available experimental results. Moreover, we conducted the influencing factors analysis for unidirectional FRP composites. This work provides a feasible and convenient method to predict the temperature dependent tensile strength of unidirectional FRP composites, and could offer beneficial insights for the material evaluation and optimization. (C) 2020 Elsevier Ltd. All rights reserved.