Test Method of the ε_rms-N Curves of Laminated Composite Beams

Abstract:

Two kinds of beam specimens made of composite laminated panel were designed and used to do vibration fatigue test for ε-N curves. the shapes of various simulated joint configurations for the specimens were adopted in order to get the accurate results. They were two kinds of double-cantilever beams supplied by T-mode stiffener and L-mode stiffener. All beam specimens were tested under the same shape of narrowband spectrum and the several loadings of random vibration by shaker excitation. The bandwidth of the narrowband random spectrum was 1/3 octave bandwidth whose centre frequency was the first resonance frequency of the cantilever beam, so that it reduced influences of the difference of specimens resonance frequency. Fitting vibration fatigue test results, the ε-N curves would be obtained then. The vibration test shows that this method of getting ε-N vibration curve is feasible. It can be used in practice.