Fatigue life prediction for composite materials

Nine types of glass fiber reinforced epoxy specimens were subjected to spectrum fatigue loading. Among them were plain and notched specimens but also a bending specimen, a cylinder, and bonded joints. Two random load spectra and MiniTWIST, FALSTAFF and WISPER were used. Spectrum fatigue life was predicted using Miner's rule and the Relativ-Miner rule. The accuracy of the predictions varied considerably.