Hygrothermal Effects on Strength of Mechanical Joints Prepared from Glass Epoxy Composite Laminates

Abstract

The climatic conditions of the earth are rapidly changing, and every year, an increase in CO2 content is reported in the earth s environment. On the other hand, development in the technology and growth in population has increased the consumption of natural resources of our planet. To tackle these problems, scientists and the industry are focused on alternative light-weight materials, which can improve the efficiency of the vehicles and also reduce the overall emissions in the environment. Therefore, the demand of the light-weight and high strength materials brought forth the composite materials. To manufacture and transport a big structure of a composite involves joining of the composite to composite or composite to metals and alloys. Adhesive joints being permanent may damage the primary components made of composites while opening the joints for maintenance. However, the mechanical joints facilitate easy assembly and disassembly when required and thus preferred over adhesive joints. The mechanical joints seem to be simple, but they are much more than that because of stress concentration due to drilled holes. Improper design of a joint may lead to a failure of the whole structure. Fiber reinforced plastics (FRPs) used in marine and aerospace structures are generally exposed to high level of humidity and temperature. Consequently, the durability and performance of the structures made of FRPs have become a primary concern for composite designers. The main objective of the present work is to improve the durability and performance of mechanical joints made of glass fiber reinforced plastic (GFRP) composites. The metal insert was used at the pin-hole interface to improve the performance of the single pinned joint. Addition of nanoclay into the epoxy further enhanced the performance of the pinned joints made of glass fiber reinforced composite material. The geometric parameters, i.e., edge distance to hole diameter (E/D) ratio and width to hole diameter (W/D) ratio were varied from 2 to 5 and 3 to 6, respectively.