Performance of high strength structural bolts in tension: effects of tolerance classes

Structural bolts have been manufactured for building construction for hundreds of years. In practice, failure of high strength structural bolts might be caused by their tolerance classes or coating procedures, which may weaken their internal or external threads. However, this research work is dedicated to understanding a bit more on bolt performance in tension, accounting for effects of tolerance classes in the applied numerical simulation for assessment of performance of structural bolts subjected to tensile loading. In addition, different constitutive relationships has also been taken into account in the numerical analysis in use of both implicit and explicit methods. The observed simulation results demonstrated two failure mechanisms for structural bolts, threads stripping and bolt shank failure, which has proved to be associated with their tolerance classes and coating procedures applied. As a result of this, carefully selecting bolts and nuts is a deliberate solution in preventing the premature failure (threads stripping) in bolted connections for performance-based steel construction.