Fatigue Life Estimation of FRP under Superimposed Sinusoidal Wave and Various Random Load Patterns

Abstract

Investigation was firstly made on the estimation method of fatigue life for FRP subjected to superimposed sinusoidal wave loads. Secondly, the fatigue life estimation was performed for three different load patterns programmed with triangular waves. Fatigue tests were conducted under both a constant stress amplitude and various programmed load patterns by a hydraulic fatigue testing machine.
The test results showed that it is possible to make the fatigue life estimation for FRP under various superimposed sinusoidal wave loads based upon the frequency dependence of fatigue with the aid of the equivalent frequency method studied in the previous paper. The fatigue life under various load patterns can also be estimated to some extent by employing the equivalent stress range for the evaluation of stress value in random waves.