Post-impact Fatigue Response of CFRP Laminates under Constant Amplitude and Programmed FALSTAFF Spectrum Loading

Post-impact fatigue response of Carbon Fibre Reinforced Polymer Woven Roving Mat (CFRP-WRM) laminates under constant amplitude (CA) and programmed version of FALSTAFF (Fighter Aircraft Loading STAndard for Fatigue and Fracture) is presented here. Stiffness degradation as a function of number of cycles of loading at varying percentages of strength after impact (SAI) was investigated after subjecting the specimens to 53 J of impact. The stiffness loss can be classified into three ranges: primary, secondary and tertiary. The loss of stiffness as a fraction of failure life under programmed FALSTAFF loading was observed to be less severe compared to CA loading.