Adhesive behavior of sisal and jute composite exposed to three months cyclic temperature variation

Abstract

Fiber Reinforced Plastics (FRPs) are being used extensively in various engineering applications ranging from aerospace to sports goods. In recent years, environmental concerns and awareness have challenged engineers and scientists to develop materials that are sustainable and have the potential to replace the traditional FRPs. Natural fiber-based polymeric composites (NFRPC) are now being investigated and proposed worldwide for various applications, especially automotive components and domestic products. To ensure the fabrication of highly intricate composite products, joining becomes inevitable. Adhesive joining is the most commonly employed fabrication process for composite joints. However, the performance of adhesive joints is susceptible to their exposure to different environmental conditions. In the present experimental investigation, the joint strength of woven fiber mat (sisal, jute, and hybrid) reinforced epoxy composites has been investigated in Three Months Cyclic Temperature Variation, and the natural fiber reinforced epoxy adherends have been successfully joined using adhesive along with two/four holes in the overlap area. The performance of the adhesive joints has been investigated under a daily thermal cycle from 5 °C (12 hrs.) to 40 °C (12 hrs.), for three consecutive months. It was observed that the hybrid composites recorded better-joining performance. Moreover, the Field Emission Scanning Electron Microscopy (FE-SEM) has been used to understand the failure mechanisms during tensile testing of adhesively bonded natural fiber-reinforced composite laminates. It has been found that the exposure of the composite joints to a variable temperature during the day has a significant effect on their tensile behavior. The major factors affecting the performance of joints exposed to the thermal cycle are; the type of natural fiber, the number of holes in the adherend area, and the duration of exposure. The results are important for the designers of composite structures with adhesively bonded joints.