Interaction effect of out of plane waviness and impact damages on composite structures – An experimental study

Abstract This publication provides the results of a test campaign with 105 specimens to investigate the interaction effect between manufacturing induced out of plane waviness (OoP) and low velocity impact damages on the compressive strength of a quasi-isotropic laminates (QI). The test campaign differs from existing experimental studies by examining the above-mentioned interaction as well as the waviness and impact effect on the compression strength in dependence on waviness angle, affected plies and affected 0°-plies. The geometry and layup of all Compression after impact (CAI) and plain strength compression (PSC) specimens were manufactured according to the Airbus standards, with the exception of the induced waviness in the defective specimens. The influencing factors of waviness, impact and their interaction were identified and meaningful physical relationships related to the interaction were derived experimentally. The results show that the effect of waviness on the residual strength of impacted specimens depends on various conditions, such the number of affected 0°-plies in dependence on the waviness angle and waviness morphology. Relevant parameters in case of individually considered defects are not necessarily relevant in case of damage interaction. The test results indicate that the interaction between impact and waviness of the investigated configurations represents a multiplicative relationship.