Investigations on Tensile and Flexural Behavior of Delaminated E-Glass/Epoxy, Carbon/Epoxy and E-Glass/Carbon/Epoxy Composites Using Hybrid Teaching Learning-Based Optimization

Abstract

The defects in the fiber reinforced polymer composites may occurs during the production process and/or due to low velocity impact. These defects initiate a more crucial damage form such as delamination. The delamination is a common failure and which destroys the structural integrity of composites. Hence, to study the influence of induced delamination on tensile and flexural performance of E-glass/epoxy, carbon/epoxy and carbon/E-glass/epoxy composites, the laminates were manufactured with constant fiber volume fraction inserting an artificial defect (polytetrafluoroethylene) at the preferred interface. Artificial defects with circular and square shapes were used in the present study to have a controlled defect size and form. The location of artificial defect in E-glass/epoxy and carbon/epoxy composites did not affect their tensile strengths considerably whereas the tensile strength of hybrid composite was affected. Moreover, the flexural properties of delaminated composites were affected by both the defect shape and its location in thickness direction due to variation in bonding strength in thickness direction. Thus, a hybrid teaching learning-based optimization (HTLBO) was implemented to suggest a delaminated composite with optimal control parameters (location of defect, area of defect and density of composite) for minimization of tensile and flexural strengths. The experimental results were compared with those of HTLBO and they agreed within 4% error.