Tensile Fatigue Properties of FRP

Abstract

The effects of properties of the matrix and the glass content on the fatigue properties of FRP were investigated under pulsating tensile stresses, using specimens which were reinforced with roving plain woven glass-fabrics. The results are summarized as follows : (1) FRP which uses a large flexible resin as matrix decreases its fatigue strength in high cycle tests. But this effect does not appear in low cycle tests. (2) The fatigue strength increases in proportion to an increase in the volumetric content of glass fiber within a certain limit, and the ratio of the fatigue strength at 10⁶ cycles to the ultimate tensile strength is nearly equal to 0.4. (3) The micro failure caused by the behavior of glass-fabrics (which was mentioned in former reports) affected the fatigue properties of FRP. Their stress-cycle curves fall in the region of the strain which caused cracks inside of the warp strands.