Study of impact energy and hardness on reinforced polymeric composites

Abstract

The effect of the type of reinforcement was studied using Charpy impact test as well as hardness test. The material used is composed of polyester reinforced with fiber glass; a material increasingly and widely used in plenty of engineering applications, recently. In order to maximize the output of the present work, studies were carried out on different weight fraction of reinforcement. Two types of composite reinforcement were tested, namely the use of chopped fibers (randomly distributed glass fibers) and woven roving (laying fibers normal to the randomly distributed ones). It has been noted that the values of the Charpy impact resistance and hardness of the tested specimens, yield increases for weight fractions of reinforcement of about 30% to 40%. The results show that there is a scatter in the values of Charpy impact resistance and hardness in the ranges of weight fraction below and higher than the 30% to 40% range. It is also observed that the values of Charpy impact resistance and hardness of the chopped composites are higher than those of chopped and woven roven ones due to the fiber distribution and orientation. The direction of the load is at random angles of orientation to the Chopped fibers in the case of Chopped fibers. The paper discusses the results to explain the out coming trends.

Characterization of Physical, Mechanical and Fire Properties of Fiber Glass Composite due to Weight Fraction

“…This may be attributed to the possibility of having a more uniform distribution of the fiber glass in the outer layers of the composite for this weight fraction. Also, these figures indicate that the Barcol Hardness value continuously increases as the weight fraction increases up to 40% and decreases after that[4].…”

Effect of fiber orientation on the mechanical properties of multi layers laminate nanocomposites

“…Maximum and minimum Barcol hardness values of the composite samples were found to be 45 and 33, respectively. This decrease in the Barcol hardness values possibly resulted from voids and air bubbles that enter the random fiber samples during the preparation process [29]. In continues fiber glass the woven structure produces pockets from resin in the cross-over points which play a significnt role in enhancing the hardness values.…”

“…Because of the weak bond between the fibers and resin in random fiberglass, it showed lower absorbing energy compared with continuous fiberglass. Also the enhancing in impact strength may be due to the possibility of having a more uniform distribution of fiberglass in woven structure comparing with random structure [29] Which reduces the effect of resin pockets also the intertwined nature of woven structure helps in dispersing the effective load which increases the amount of absorbing energy. In random fiber samples, the weak bonds between the fibers and matrix (polyurethane resin) can cause propagation for the cracks through the composites, thus absorbing much less energy in the random fiber samples.…”

The effect on the tool flank wear width VBmax during turning of Hybrid Mg/(8wt% SiC(p) +2wt% Al2O3(p) +1wt% Gr(p) MMC using PVD coated cermet tool

“…Rubio et al [8] used an L27 orthogonal array to optimise the parameters for the dry facing of magnesium in order to evaluate surface roughness, and they discovered that 0.04 mm/rev feed rate, 280 rpm spindle speed, and TP2500 tool coating are the best combinations for minimizing surface roughness. Hasan et al [10] examined the effect of the reinforcement, i.e. chopped fibres and woven roving, and discovered that as the particle strength and specimen hardness increased, so did the impact strength and specimen hardness.…”