Loading Rate and Temperature Dependence on Flexural Fatigue Behavior of a Satin Woven CFRP Laminate

Generally, the mechanical behavior of polymer resins depends remarkably on time and temperature, which is called viscoelastic behavior. Thus, it can be presumed that the mechanical behavior of a CFRP using polymer resins is also time and temperature dependent. In this paper, the loading rate and temperature dependence on flexural fatigue behavior of satin woven CFRP laminates consisting of a matrix resin with a high glass transition temperature is investigated. The results show that not only flexural static strength but also flexural fatigue strength of the CFRP laminate depends on time and temperature even at temperatures that are much lower than the glass transition temperature. The reciprocation law of time and temperature was found to be applicable for both the flexural static and fatigue strengths. The fatigue and static fracture modes were found to be similar for the wide ranges of time and temperatures tested. The slope of the S-N curves also remains the same despite the large temperature range and two frequencies tested. From the above results a prediction method for flexural fatigue strength at an arbitrary temperature and frequency is proposed.