Acoustic Emission based Monitoring of Cut-out Geometry Effects in Carbon-Epoxy Laminates under Uni-axial Compression

Abstract

In this paper, symmetric cross ply CFRP laminates were fabricated using hand layup with LY556 epoxy resin as matrix and the specimens were cut without cut-out, with circular, vertical elliptical and horizontal elliptical cut-outs according to the ASTM D 7137 standard using water jet cutting. The CFRP specimens with and without cut-outs were subjected to compression under controlled condition accompanied by acoustic emission (AE) monitoring. The ultimate compressive strength for specimens with and without cut-outs were determined and compared. The optimum cut-out with lesser reduction in compressive strength was determined. The nature and dominance of different failure modes in each type of cut-out were investigated using AE. Finally the result gives useful information about improved design of laminated composites with cut-outs suitable for different applications.

Parameters influencing the impact response of fiber-reinforced polymer matrix composite materials: A critical review

“…It was noticed that as the ratio reduced, the peak force raised and the contact duration shortened. The post-impact residual compressive and tensile properties of composite structures are affected by the damage area and mechanisms produced by the impact [267][268][269][270][271]. Dhakal et al [272] studied the effects of impact tup geometries on the damage resistance of non-woven hemp fiber reinforced unsaturated polyester composites under lowvelocity impact.…”

Residual strength and damage characterization of repaired glass/epoxy composite laminates using A.E. and D.I.C

“…The combination of several failure modes like matrix cracking, fibre/matrix debonding, delamination, and fibre micro buckling can all influence the compressive strength of the laminate [12]. Many authors [17][18][19] used online AE monitoring techniques to qualitatively characterize the failure mode in composite laminates. When a composite laminate is strained, different damage modes are activated such that, a fraction of the whole strain energy is dissipated as a wave that transmitted from the damage source all the way through the medium.…”

Effect of multiphase fiber system and stacking sequence on low‐velocity impact and residual tensile behavior of glass/epoxy composite laminates

“…For instance, in Columbia space shuttle, the impact of frozen foam on the wing induced a catastrophic failure . Hence, numerous investigations have been carried out to understand the impact behavior of composite structures .…”