Mechanical performance of intraply and inter-intraply hybrid composites based on e-glass and polypropylene unidirectional fibers

The aims of this study are to design, fabricate and investigate the mechanical properties of new hybrid composite laminates made from polypropylene-glass unidirectional fibers and epoxy matrix. Specimens were fabricated following the hand lay-up technique in intraply and inter-intraply configurations. Results are presented regarding the tensile, flexural, in-plane shear and interlaminar shear behaviors of fabricated composites with particular consideration of the effects of the plies stacking sequence and hybrid configuration. The experimental results reveal that the mechanical properties of polypropylene/epoxy composite can be effectively improved by the incorporation of glass fiber through the formation of either intraply or inter-intraply hybrid composites. With a proper choice of the hybrid configuration and the plies stacking sequence, the fabricated hybrid composites achieved property profiles close to those of homogeneous glass reinforced laminate in terms of specific properties. Resistance of the intraply hybrid composite to tensile and flexural loadings is higher than inter-intraply hybrid composites. On the other hand, the highest in-plane and interlaminar shear strengths are associated with the inter-intraply hybrid composite with glass fiber core. Additionally, an analytical analysis was also introduced to provide a good correlation with the experimental data, which give an insight on the ideal plies stacking sequence to achieve the required properties.