Damage Identification in CRFP Laminates using a Statistical Method

Abstract

The purpose of this research is the detection and classification of impact damage in structures made from composite materials. This paper discusses classification of damage extent and type based on the use of X-ray analysis and a Scanning Electron Microscopy (SEM) technique. The composite material chosen for this research is a Carbon Fibre Reinforced Plastics (CFRP) laminate. The material was laid-up to produce plate specimens of 250 mm × 150 mm with 11, 12 or 13 layers. Piezoelectric sensors were placed on three different points of each test specimen in order to record the responses from impact events. An experimental modal analysis system was used to collect responses from both damaging and undamaging impacts. To perform the damaging impact tests, an instrumented drop test machine was used and the impact energy was set to range from 0.37 J to 41.72 J. The signals captured from each specimen were recorded for evaluation and the impacted specimens were X-rayed and SEM techniques were used to evaluate the extent and type of the damages. Statistical methods were used to classify the impact events into damaging and non-damaging and also to correlate the damage type and extent with the impact energy.