Prediction of the residual tensile strengths of carbon-fiber/epoxy laminates with and without interleaves after solid particle erosion

In the present work, the influence of stacking sequence, existence and position of interleaves on the solid particle erosion in carbon-fiber-reinforced epoxy composites (CFRP) was investigated. The erosive wear behavior was studied in a modified sandblasting apparatus at a 90° impact angle. The erosion behavior was considered as a repeated impact procedure (impact fatigue). A semi-empirical approach initially developed for the prediction of the residual strength after single impact was adopted and evaluated in the case of erosion conditions. The model takes into account the inherent material properties, the initial and post-impact tensile strength of the material and the visco-elastic response (mechanical damping) of the non-impacted material. The excellent agreement between theoretical predictions and experimental values corroborated the reliability of this model which may be a useful tool for the prediction of the post impact residual strength in the case of solid particle erosion. Results showed that for impact energy values lower than a characteristic threshold the damage induced does not affect the residual tensile strength after solid particle impact (erosion) of the materials. It was also established that this threshold depends on the orientation of the plies, the existence of interleaves and the energy absorption capacity of the material.