Machining Of Fiber Reinforced Polymer Composites Research Articles

A review on the effects of input parameters & filler composition on delamination during machining of FRP composites

In epoch usage of fibre-reinforced polymer (FRP) material are increasing day by day. Weight sensitive structural components like FRP are utilized in industries like Aerospace, Automobile etc, thus assembly of FRC requires drilling operation. Drilling a FRP is quite tough as drill tool undergo variable opposition while fleeting through the alternate layer of fibre and matrix. Drilling of FRP laminates ends up in fibre peel-up and obtrudes which is known as delamination. Rejections of FRP laminates occur due to delamination. Process input parameter {feed (F), cutting speed (S), drill diameter (D), point angle (θ), drill bits (db), chisel edge (E) and fibre orientation angle (α)} and fillers (glass micro balloon (% GMB), carbon tube nano (%CNT) & shows a large role in reducing delamination in FRP. Various Analytical models and Finite element method exist in the literature to investigate the nature of delamination during drilling of FRP composites but none of the researcher identified method to urge delamination free holes. During this review paper, an in-depth effect of all processes parameter and filler percentage on delamination in drilling of FRP composites is highlighted.

Heat effect on the material removal in the machining of fibre-reinforced polymer composites

Abstract This paper aims to investigate the heat effect on the material removal mechanisms in the machining of fibre-reinforced polymer (FRP) composites. A coupled thermal-mechanical microstructured-model was established to investigate the cutting processes both with and without ultrasonic tool vibration. A systematic cutting experiment was also conducted to assess the reliability of the theoretical predictions. It was found that the cutting temperature influences significantly the material removal process, but has a little effect on the cutting forces. The fibres and matrix deform and fracture in brittle modes when the temperature is below the glass transition point of the matrix material, Tg. The matrix material becomes softer and its deformation turns to be ductile when the temperature exceeds the glass transition point. This consequently brings about significant deformation and fracture of fibres in the subsurface. During cutting, with increasing the cutting time, the cutting-induced heating zone spreads quite ahead of the cutting edge. However, with the assist of ultrasonic vibration, the high-frequency motion of the cutting tip dramatically reduces the tool-work interaction time at each vibration cycle; thereby slows down the heat generation and temperature rise. The high-frequency motion also leads to rapid chip removal and reduces temperature rising rate and heat accumulation. As a result, both the tool and workpiece temperature can be maintained to be below the Tg of the matrix material. Nevertheless, the advantage of the vibration-assisted process becomes trivial once the feed rate is larger than its maximum vibration speed.

Tool wear and its effect on the surface integrity in the machining of fibre-reinforced polymer composites

This paper investigates, both experimentally and theoretically, the tool wear in the cutting of fibre-reinforced polymer composites as well as its effect on the surface integrity of the machined composites. It was found that the main mechanism is friction-caused flank wear, and that the introduction of ultrasonic vibration to the cutting tool can drastically reduce its wear rate. It was identified that tool wear not only influences cutting forces and chip formation as usually understood, but also affects significantly the material removal mechanisms and surface integrity of the machined composites. The study revealed that in a traditional cutting process, the chip formed by a fresh cutting edge is larger than that by a worn cutting edge, and that friction-induced bending fracture can occur in a machined subsurface as the tool wears out. The vibration-assisted cutting, however, reduces tool wear due to the much shortened tool-workpiece contact time in each cycle of the tool vibration.

Effect of tool vibration on chip formation and cutting forces in the machining of fiber-reinforced polymer composites

ABSTRACTThis article investigates the chip formation mechanism and its influence on cutting forces during the elliptic vibration-assisted (EVA) cutting of fiber-reinforced polymer composites. To clarify the effect of the vibration, systematic finite element and experimental studies were performed on both the EVA and the traditional cutting of unidirectional fiber-reinforced polymers with various fiber orientations. The key factors that govern the cutting forces have been taken into account, such as the depth of cut, feed rate, tool vibration frequency and amplitude. The study found that fiber orientation significantly affects the chip formation and cutting forces. Fiber fracture can happen either above or below the trimming path, but that above the path dominates chip formation. When a fiber orientation is less than 90°, chipping is mainly through bending-induced fracture of fibers; when it is beyond 90°, however, chipping is mostly by crushing the fracture of fibers. Compared with a traditional cutting process, the EVA cutting can minimize the fiber orientation effect through localized fiber fracture. A dimensional analysis was then performed to provide a quantitative prediction of the cutting forces.