Effect of Intralaminar Failure Properties on Compressive Strength of CFRP Structure after Edge-on Impact

Abstract

Strength of compression after impact is one of the most important design criteria for structures using laminated fiber-reinforced plastics. Effects of face-on impact damage on compressive strength have been widely studied over the past decades. However, knowledge about effects of edge-on impact damage is limited compared to that of face-on impact. Therefore, in this study, edge-on impact tests and compression after edge-on impact (CAEI) tests were conducted. In addition, intralaminar fracture toughness (energy) of compressive failure of fiber (0°) and matrix (90°) was obtained by single edge notched compression tests and VCCT analysis, since intralaminar failure properties seem to be essential from our previous work. The obtained toughness was used in progressive damage analysis (PDA) of CAEI failure. In the PDA, CAEI failure was simulated under several modelling assumption of impact damage, including delamination and intralaminar pre-crack. As a result, CAEI strength was predicted with relatively small error when intralaminar pre-crack was included as impact damage. Although modelling assumption of impact damage, such as information about crack length or cracking ply, has to be validated based on experimental observation as future task, utility to predict CAEI strength by modelling impact damage as pre-crack was shown.