Abstract:
Accelerated water bath moisture absorption tests at 25 ℃ and 50 ℃ were carried out on carbon fiber reinforced polymers (CFRP) laminates, and the uniaxial tension and three-point bending tests were performed. The rule of the moisture absorption, tensile strength and bending strength varying with the moisture absorption time and the bath temperature was studied. The failure mechanism of the CFRP laminates was discussed. A residual strength model of CFRP laminates was established by fitting the experimental data. On the basis of the environmental equivalent coefficient, the hygrothermal aging life of the laminates was predicted. The results show that the average saturation moisture absorption rate of CFRP laminates at 50 ℃ was 0.77%, and was larger than 0.33% at 25 ℃. At the same moisture absorption time, the moisture absorption rate at 50 ℃ was higher than that at 25 ℃. The tensile strength and bending strength decreased by 7.4% and 17.2% after moisture absorption saturation at 50 ℃ compared with that before moisture absorption, respectively, and the decrease degree was higher than those after moisture absorption saturation at 25 ℃. The higher the bath temperature, the more serious the interface damage between CFRP laminate carbon fiber and resin, and the more obvious the cracks. The real aging life prediction method on the basis of residual strength and environmental equivalent coefficient could provide evidence for the service reliability evaluation of CFRP laminates in hygrothermal environment.