Drop impact damage assessment of Glass fibre reinforced polymer Composite through damage Tolerance method using acoustic Emission and ultrasonic techniques

Abstract

Composite materials are being used in many industrial applications due newlineto their higher strength to weight ratio as compared to metals In recent years newlineGlass Fibre Reinforced Polymer GFRP has found wide application due to its newlinehigh strength better impact resistance and ease of manufacturing In newlineaerospace and other applications drop weights create invisible damage Drop newlineloads lead to various problems such as matrix crack fibre breakage newlinedelamination fibre pullout etc Therefore a damage assessment method in newlinereal time becomes necessary to take the corrective action needed to avoid newlinemajor accidents In this work an attempt has been made for the investigation newlineof drop impact damage on GFRP composite laminates using the Ultrasonic newlineTechnique UT and Acoustic Emission Technique AET newlineThe drop impact test on the GFRP composite laminate was carried out newlineusing the drop impact apparatus It was found that the area of the drop impact newlinedamage vary with respect to impact energy The drop impact damaged newlinecomposite laminates were scanned by an ultrasonic flaw detector in the newlineA scan mode and the ultrasonic signals were analysed The ultrasonic newlineParameters namely the amplitude the attenuation coefficient and attenuation newlineratio were calculated It was found that the attenuation coefficient increases newlinewith an increase in the area of the impact damage The attenuation coefficient newlineincreases from 0 07 nepers mm to 15 04 nepers mm for the area of impact newlinedamage range of 102 mm2 to 742 mm2 It was also observed that the amplitude newlineand attenuation ratio of the impact damaged composite laminate decrease with newlinean increase in the area of the impact damage newline