Effect of Epoxy Coating on Structural Steel Section under Tension

Abstract

Structural steel connections are one of the most critical components of any steel structure as the cross-sectional area of steel sections reduces due to bolt holes. Failure of a structural connection may lead to failure of entire steel structure. Many researchers have tried to improve the connections previously by gluing fiber polymers at the connection. In this research glue or epoxy has been used around the bolt holes to simplify the process of using fiber polymers with steel. Epoxy is a combination of resin and hardener. It is proposed here to strengthen the structural steel connection in new structures and also in existing structures by applying a thin coat of suitable epoxy around the bolt hole. Thin steel plate with hole at the centre was tested under tensile load and results for ultimate load, breaking load, corresponding stresses and displacements obtained. Another steel plate with same geometry was then epoxy coated around the hole and same test was conducted on this specimen. Results for yield, ultimate, breaking loads and corresponding stresses and displacements recorded. The load-displacement curve is generated for both the cases and compared. The ultimate load bearing capacity of the plate increased in tension slightly after epoxy coating. Significant increase in breaking load observed as the thickness of epoxy layer was increased. Increase in the ductility of the composite plate is seen as increase in displacement is visible. There was considerable reduction of average stress around the center hole. The results indicate that structures can be safer against total failure and will give adequate warning before collapse.