Fatigue performance of undamaged and repaired composite sandwich beams

摘要

The behaviour of undamaged (i.e. as-manufactured) and repaired carbon fibre reinforced plastic (CFRP) sandwich beams loaded in cyclic four-point bending is described. Three repair configurations (one overlap and two scarf) were tested in tension and compression, and two repair systems (high- and low-temperature cure) were employed. The repaired beams always showed an inferior performance compared with the as-manufactured beams. The lifetime was dependent on the repair configuration, with the overlap repairs performing surprisingly well when loaded in compression. The degradation of stiffness with cycling was also investigated and was related to the microscopic evolution of damage.