Temperature Effect on Monotonic Strength of FRP Composite Laminates with Various Lay-ups

Fibre-reinforced polymer (FRP) composites fall into the class of viscoelastic materials, and their mechanical properties are significantly influenced by temperature. The present study develops a model to take into account the effect of temperature (T) on monotonic strength of FRP composites namely the ultimate tensile strength (σult) and Young’s modulus (E). It was found that the variation of σult and E with temperature in 0° lay-ups is usually very small, and the parameters remain almost unchanged by increasing temperature to around the polymer matrix melting point of the composite. However, due to the matrix dominancy, σult and E in 90° lay-ups usually have the highest variation with temperature when compared to other plies and laminates. Cross-ply and quasi-isotropic laminates show an intermediate response between the two lay-ups. To characterize the temperature-dependent parameters, a shifting factor concept was introduced. Using the proposed shift factor, σult(T) and E(T) for laminated FRP composites were formulated. The proposed σult–T and E–T relations were evaluated by various sets of experimental data available in the literature. The estimated predictions of the proposed relations were found in good agreement with the experimentally obtained data when used for unidirectional, cross-ply, and quasi-isotropic FRP laminates.

کلیدواژه ها:

FRP composite ، monotonic strength ، temperature effect ، shifting facto