Time and Temperature Dependence on Flexural Strength of Heat-resistant CFRP Laminates

Abstract

The flexural fracture behavior of four kinds of CFRP laminates with the combination of heat-resistant thermosetting resin and PAN-based carbon fiber were investigated by three-point bending tests over a wide range of temperature and deflection rate. The flexural fracture behavior by the fractographs as well as the flexural strength strongly depend on the testing rate and temperature. The master curves for these strengths can be produced based on the time-temperature superposition principle. The time-temperature shift factor for the flexural strength of each laminates is quantitatively in good agreement with that for the stress-strain relation of the corresponding matrix resin. Therefore, it is cleared that the time and temperature dependence of flexural fracture behavior of heat-resistant CFRP laminates are mainly controlled by the viscoelastic behavior of matrix resin.