Instrumented impact fracture and related failure behavior in short- and long-glass-fiber-reinforced polypropylene

摘要: Abstract The fracture behavior of injection-moulded polypropylene (PP) composites reinforced with chopped, short glass fibers (SGF) and long (LGF) was studied in instrumented high-speed impact bending tests. Testing carried out on Charpy specimens different notching direction order to elucidate microstructural effects. parameters were included a reinforcing effectiveness parameter, R, which considers the fiber volume fraction, layering orientation therein, aspect ration its distribution. From tests performed at −40, 20 60°C, mechanical such as toughness, Kd, initiation energy, Gd,i, Young's modulus, Ed, derived. A distinction made between crack propagation stages based fractograms by using ductility index, DI. Addition LGF considerably improved Gd,i DI, while Ed unaffected when compared related values SGF-PP. In addition, DI did not change significantly temperature. reasonable correlation found toughness composite, Kd,c, matrix, Kd,m, considering above R parameter according efficiency (M) concept. failure modes materials fractography are discussed. It concluded that matrix fails crazing, whereas among fiber-related events debonding occur composites, while, pull-out dominate