Analysis Of Delamination During Drilling Process Of Aramid Fibre Reinforced Polymers

Abstract

Abstract Aramid Fibre Reinforced Polymer (AFRP) is a modern engineering material which is highly versatile in nature. These materials are usually used to produce impact resistant structures. Aramids have high modulus, tensile strength, stiffness, and low weight density. AFRP, under cyclic loading, shows good performance. As far as textiles and concrete structures are considered, AFRP is one of the best fiber-reinforced composites. Delamination is a failure mode that causes fracture of a variety of materials including concrete and laminate composites. A material, in general, fractures into layers due to delamination effect, i.e., separation into its constituent layers. In the present study, the AFRP polymer is prepared by hand layup method, drilling operation is done on the composite under different machining conditions, measurements regarding delamination are taken using a tool room microscope, and delamination factor is calculated by using a suitable equation. Rate of feed, spindle speed and diameter of drill are the drilling parameters under consideration. Each of these parameters are considered at three different levels. A fully crossed design consisting of 27 tests is considered to conduct experiments. The results of different experiments are analyzed statistically using Fisher variance analysis (ANOVA) to determine the impact of variables of drilling on the delamination factor. The main effects plots disclose that the lowest delamination factor is obtained for a rate of feed of 0.4 mm/rev, a speed of spindle of 1000 rpm and for a drill diameter of 15 mm. It is also noted that the delamination factor increases as the speed of spindle and diameter decreases. The interaction plot of rate of feed-spindle speed indicates that the interaction has moderate effect on delamination factor, whereas interaction plot of rate of feed-diameter represents that the rate of feed on delamination factor banks on level of drill diameter, and interaction plot of speed of spindle speed-diameter of drill demonstrates that the interaction has moderate impact on delamination factor. Also, regression analysis is done to establish the general linear model relating delamination factor and the drilling parameters under consideration.