Evaluation of the influence of preliminary low-velocity impacts on the residual fatigue life of CFRP composites

PurposeThe main purpose of this study was to evaluate the mechanical behaviour of layered fibrous carbon-fibre reinforced plastic (CFRP) under complex low-speed bending and impact loads and subsequent cyclic tensile loads.Design/methodology/approachA comprehensive approach was adopted to study the damage accumulation processes using state-of-the-art testing and diagnostic equipment. In the course of the study, a microstructure analysis of damages caused by a transverse impact and cyclic tension was performed.FindingsA dependence of residual fatigue life of the studied composite material on the intensity of the preliminary impact bending was established. Temperature field distribution fields on the surface of the sample during tests were shown. Data on damage accumulation processes were presented, which were obtained during the registration of acoustic emission signals.Originality/valueA connection was established between changes of registered acoustic response signals and thermal imaging camera data, which was supported by the results of an experimental study. The results of the comprehensive approach showed a qualitative correlation.