Abstract
Previously it has been shown that AE ring-down counts of glass-mat FRP in low-cycle fatigue loading become steady at the comparatively initial stage and their amounts are approximately linear with the fatigue life on a log-log diagram. In the present study, it was found that AE ring-down counts at each cycle during low-cycle fatigue could be evaluated from the strain response at the corresponding cycle by using the relation between strain and AE counts in static tests. It was also shown that the strain at each cycle during fatigue could be represented by the secant modulus and the modulus under unloading, and that both moduli at each cycle could be calculated from the applied stress and the secant modulus at the first cycle of the fatigue tests. Based on these concepts and then using the above-mentioned relation between AE counts and fatigue life, the prediction of low-cycle fatigue failure was made by a simulation method. A rather good agreement between the simulated and tested results was obtained.
