Multiaxis multilayered non-interlaced/non-Z E-glass/polyester preform and analysis of tensile properties of composite structures by statistical model

In this study, non-interlaced/non-Z single layer and multilayered uniaxial, biaxial and multiaxis preform structures were developed to produce E-glass/polyester composite structures. The data generated from the tensile tests of the composite structures were analyzed by using a regression model. We found that the tensile strength of the E-glass/polyester structures depended on yarn orientation and the number of layers. It was also indicated that the tensile properties of the composite structures were proportional to their total fiber volume fractions. If all the E-glass/polyester structures are made with the same preform packing density, the structures made from coarse fiber show high tensile strength, compared to structures made from fine fiber, due to high fiber volume fraction. All structures showed mode-I type delamination failure which occurred in the out-of-plane direction as a form of interlayer splitting parallel to the applied tensile load direction. Local interlayer failures were observed between warp/warp in uniaxial structures, warp/filling in biaxial structures, and bias/bias and bias/filling in multiaxis structures due to the non-Z yarn reinforcement. The developed regression model was considered as a suitable and viable tool to predict the tensile properties of the composite structures.