Abstract-Fiber-reinforced polymeric composites find widespread applications involving high and low engineering concepts. This is due to their unique properties of light weight, stiffness and high strength weight ratio. During processing and servicing, the composite materials exhibit defects such as matrix crazing, fiber breakage, fiber pull-out, delamination, and debonding. These are associated with multimechanisms. Surface and internal damages that are not visible can reduce the residual stiffness and strength of the composite laminates. Fatigue damage accumulates in composites with cyclic loading and catastrophic failure occurs when the damage exceeds a critical level. Damage mechanisms and damage accumulation in composites under cyclic loading has been the subject of many recent investigations. The basic problem in the development of a damage accumulation model is that of the definition of damage. Owing to the high complexity of mechanisms, micro damage is not directly measurable as strain and deformations. This paper deals the flexural properties of bidirectional polymeric composite through low cyclic impact test. Keywords- GFRP composites, flexural strength, fatigue, low cyclic impact. I. INTRODUCTION OW-velocity impact-induced damage in Ti/GFRP laminates as titanium-based Fibre-Metal Laminates (FMLs) was investigated to reveal the extent of internal damage in the in-plane direction and to evaluate the effects of titanium face sheets on impact damage in the GFRP core. It was found that interlaminar delamination in the GFRP layer expands widely due to crack initiation in the titanium layer on non-impacted side. However, matrix cracks and residual out- of-plane deformation are suppressed by energy absorption achieved by the bottom titanium layer. Furthermore, impact responses and damages obtained by finite element analysis with detailed modelling agree well with the experimental results. Thus, a study confirmed that the impact behaviour of K.Poyyathappan,K.Pazhanivel and S.Arunachalam are with Thiruvalluvar College of Engineering and Technology, Vandavasi, 604505, India (e-mail: poyyathu@gmail.com, rkvel2003@yahoo.co.in and arunachalamtcet@gmail.com ). G.B.Bhaskar is with Tagore Engineering College, Chennai, India, 600048 (corresponding author - phone: +91 9444140339 ; fax: +9194427409730 e- mail: bhaskarang01@yahoo.com ). M.C.Leninbabu is with PSNA College of Engineering and Technology, Dindigul, India, 624622 (e-mail:lenin_babu@yahoo.com) A.Elayaperumal is with College of Engineering Guindy, Anna University, Chennai, 600025, India (e-mail: ep_mal@yahoo.com ). the Ti/GFRP laminates is dominated by a fracture in the titanium layer on non-impacted side that fails in tension and that this layer plays a major role in preventing impact damages in the GFRP core [1]. Tae Jin Kang and Cheol Kim explained that there have been a number of reports in the field of impact behavior of composite materials, especially on the problem of the performance reduction of composite structures induced by impact. Laminated composite structures, which offer an attractive potential for reducing the weight of high- performance aerospace structures, have inferior through- thickness properties, such as interlaminar shear strength, since the laminated structures have no reinforcements in the thickness direction. There has been a considerable amount of work on these problems by many researchers, mostly with carbon fiber Composites, which are susceptible to low energy impact damage. This localized damage is potentially a source of mechanical weakness, particularly under compression loading. Most of the preceding studies had been devoted to analyzing the impact properties and post-impact compression behavior of carbon-fiber-rein- forced composites with a view of improving their impact-tolerance properties. The delaminated areas in the woven laminates were much larger than those in the multiaxial warp-knit composites, while the delamination energy absorption was slightly higher since the impact fracture toughness of the woven laminate was much smaller than those of the multiaxial warp-knit composite [2]. The performance of a fibre-reinforced composite is determined by its fiber orientation. Unidirectional fibers provide maximum strength and modulus when the load is applied in the fibre orientation [3]. Performance of an engineering product largely depends on its design, manufacturing quality and service response. Apart from strength requirements of composite, specifically high-energy dissipation/unit mass is also possible with composite materials by initiating and maintaining proper failure mechanisms during the crack event. Metals absorb energy through plastic deformation, whereas glass fiber reinforced composites absorb energy through failure mechanisms involving delamination, interply cracking, and fiber fracture, energy absorbency of a structure is directly dependent on the failure mode that occurs, and the failure mode is a function of the loading history and environment [4]. The impact damage profile was strongly related to the degree of anisotropy in their tensile properties. For weft knitted fabric Fatigue Flexural Properties of Glass Fiber Reinforced Plastic Composites Subjected to Low Cyclic Impact K.Poyyathappan, K.Pazhanivel, G.B.Bhaskar, S.Arunachalam, M.C.Leninbabu, A.Elayaperumal L 2nd International Conference on Mechanical, Production and Automobile Engineering (ICMPAE'2012) Singapore April 28-29, 2012 229