This study investigated the effect of aviation turbine fuel exposure on interlaminar and in-plane shear properties of E-glass/epoxy composite. The two types of test specimens, namely bare and resin-coated specimens with varying thicknesses as per the ASTM standard, were made out of E-glass/epoxy composite to evaluate their interlaminar and in-plane shear properties. These all types of specimens were immersed inside the aviation turbine fuel for two months and then afterward their effect on the reduction of mechanical properties like interlaminar and in-plane shear tests properties were experimentally investigated. Test results show that ATF fuel exposure has reduced the interlaminar shear strength by 10.04 %, 7.83 %, and 6.01 % for bare, with 0.1 mm and 0.2 mm resin coating, respectively. Similarly, in-plane shear strength was reduced by 14.75 %, 11.22 %, and 7.52 % for bare, with 0.1 mm and 0.2 mm resin coating, respectively, and in-plane shear modulus was reduced by 10.87 %, 8.94 %, and 6.52 % for bare, with 0.1 mm and 0.2 mm resin coating conditions as compared to as-received (without ATF exposure) specimens.SEM micrographs and results too showed that properties were reduced and indicated that the glass/epoxycomposite was resistive to fuel ingression. It was observed that bare specimens exhibited a reduction in shearproperties due to ATF ingression to the polymeric network and induced internal stresses, which not only degraded the matrix and fiber-matrix adherence but created micro-cracks too in the resin at interfaces. Resin-coated specimens limit fuel ingression, which has led to a reduction in properties.

Quartz-Fibre-Reinforced cyanate ester Plastics (QFRP) has superior performance in terms of mechanical, electromagnetic properties and are being widely used in military applications. Drilling is the general machining process for making hole to join the composite part to another sub-assembly. This study presents an influence of optimized drilling parameters on carbide tool wear and its impact on hole characteristics in QFRP composite. The aim is to achieve the optimum use of drill during the drilling process from application perspective without compromising the quality. In addition, the effect of tool wear and its impact on residual tensile strength of quartz composite are studied. The dominant wear mechanism observed is flank wear caused by the abrasive nature of the quartz fibre. The tool wear and delamination factor after drilling 200 holes are 186 µm and 1.40 respectively. The residual strength is affected by the tool wear due to relatively poor interlaminar property between fiber and resin in this quartz composite. The residual strength of quartz specimen drilled with the tool after drilling 200 holes is 14 % lower than the property of specimen drilled with fresh drill. The highlight of the present work is a combined analysis of wear in the tool, delamination induced and residual strength of quartz specimen. The results of this study strengthen the understanding of the drilling process of quartz polymeric composite material in aerospace applications.