Experimental determination of fracture toughness of woven/chopped glass fiber hybrid reinforced thermoplastic composite laminates

Today the polymer composites have a special standing and widespread application in engineering practices. The industrial application of different materials requires the identification of their properties. Also, the safe formation of laminated composites requires detrimental factors to the identified. This requirement comes to be a source of motivation for researchers to investigate the propagation characteristic of cracks to explore the detrimental factors. Thus in the present study, the fracture toughness of the composite structure was investigated by performing compact tensile and compact compression tests for hybrid fiber reinforced polypropylene composite laminates which have three types of composition with various thicknesses, fiber contents, and woven and/or chopped glass fiber reinforcement. The critical energy release rates of fiber and matrix in both tensile and compressive fracture cases were determined in pre-cracked specimens under plane-strain loading conditions. In the present study, the longitudinal fiber breakage/buckling and the transverse matrix crack/crushing are defined as the damage mechanisms of the composite materials. As a result of the longitudinal tension, the damage progressed gradually in the form of translaminar fiber breaking in materials containing continuous fibers. In the transverse tension process, fiber-matrix separation caused intralaminar deformation in the materials. The highest fracture critical energy release rate was found in the material with the maximal fiber layer. (C) 2021 Sharif University of Technology. All rights reserved.