Damage resistance and damage tolerance of a double-double fiber-reinforced polymer composite laminate to impact

Abstract

This article analyzes the damage tolerance after impact of an unconventional carbon/epoxy laminate (AS4/8552) of the Double-Double (DD) type tested with different impact energies and compares it to a traditional laminate with equivalent properties. Quadriaxial (QUAD) laminate has stacking sequence [03/90/±45]S and the DD equivalent laminate has stacking sequence [0/-55/0/+55]3T. These materials were subjected to the low velocity impact test (LVI) with three energy levels (30 J, 45 J and 74 J), the uniaxial compression test and the compression after impact (CAI). The objective of this article is to validate whether the proposed DD laminate can be a replacement for the QUAD presented, considering the behavior under impact. In addition to the comparative study, this article also has the objective of evaluating whether it is possible to relate the damage tolerance with the delaminated area, and for this purpose, X-ray computed tomography (CT) was performed, making it possible to measure and locate the damage found in the samples.