As the application of fibre-reinforced polymer composite material continue to increase day by day, so the knowledge about the impact behaviour of fibre-reinforced polymer composite structures in the areas such as automotive and aerospace is very much needed. This article attempts a comprehensive review of recent literature in the broader area of impact damage. Testing methods and standard parameters as well as discussion of important aspects such as impactor shape, weight of impactor, velocity of impact, environment in which impact takes place are presented. Furthermore, the damage area, energy absorbed, contact time and many other considerations are discussed. Finally, an effort is made to review the research work by considering all aspects related to impact on such type of composite materials.

Fiber-reinforced polymer composites are becoming suitable and substantial materials in the repair and replacement of conventional metallic materials because of their high strength and stiffness. These composites undergo various types of static and fatigue loads during service. One of the major tests that conventional and composite materials have to experience is fatigue test. It refers to the testing for the cyclic behavior of materials. Composite materials are different from metals, as they indicate a distinct behavior under fatigue loading. The fatigue damage and failure mechanisms are more intricate in composite materials than in metals in which a crack initiates and propagates up to fracture. In composite materials, several micro-cracks initiate at the primary stage of the fatigue growth, resulting in the initiation of various types of fatigue damage. Fiber volume fraction is an important parameter to describe a composite laminate. The fatigue strength increases with the increase of the fiber volume fraction to a certain level and then decreases because of the lack of enough resin to grip the fibers. The fatigue behavior of fiber-reinforced polymer composites depends on various factors, e.g., constituent materials, manufacturing process, hysteresis heating, fiber orientation, type of loading, interface properties, frequency, mean stress, environment. This review paper explores the effects of various parameters like fiber type, fiber orientation, fiber volume fraction, etc. on the fatigue behavior of fiber-reinforced polymer composites.

Interlaminar fracture toughness had been the subject of great interest for several years and is still interesting to the research community. In this article, a comprehensive analysis of fracture toughness in FRP laminates is presented. Primarily, toughness studies are undertaken on glass and carbon fiber reinforced composites under mode-I and mode-II loading conditions. The fracture behavior and its failure pattern depend on a number of parameters: fiber sizing/coating, matrix modification, insert film, fiber volume fraction, stacking sequence, specimen geometry, loading rate and temperature change. In fact, a state-of-the-art process enables increasing fracture resistance with “matrix toughening by carbon nanotubes (CNT) inclusion”. It enables production of materials having ultra-high strength and low weight. The present study has highlighted the available techniques of CNT incorporation: mechanical mixing, grafting and interleaving. Other aspects, such as the dispersion level, matrix viscosity, fiber surface roughness, loading weight %, bonding strength with epoxy, height and density of grown CNT, energy absorption mechanism during delamination, etc., have been examined as well. Although a clear correlation of all these parameters with fracture toughness is hard to establish, there is growing understanding of the surface-grown CNTs and interleaving processes as they ensure significant increase in fracture toughness.

Over the last decade, the use of polymeric composite material has increased considerably, and as a result, machinability of such material has also increased. The main aim of this work is to emphasize on the conventional and unconventional machining of composite materials, more specifically on drilling of carbon fiber-reinforced polymer and glass fiber-reinforced polymer. Additional concentration on tool materials and geometry, roughness of drill surface, thrust force and delamination at entry and exit with influence of point angle of tool, variable feed rate, and variable spindle speed. Over the last few years, many studied on the effect of cutting parameters and tool geometry using conventional machining, the phenomena associated with unconventional machining of composite material requires some supplementary studies in order to make damage free machining of composite materials.