Degradation and failure analysis of bolted joints under transverse loading

Abstract

There are a huge number of bolted joints used in engineering applications. However, unreasonable design and use may lead to degradation and failure of the connected structure. Herein, finite element analysis method is used to investigate the influence of various factors on the mechanical properties of bolted joints. To simulate the actual assembly and loading process, different analysis steps were considered, given as: tightening step, initial lose step and the loading step. In the loading step, transverse load is applied to obtain the force-displacement curve. Structural parameters, i.e. clamping force, effective clamp length and assembly clearance, and coefficients of friction of all the contact surfaces are considered in the finite element analysis. The results showed that the performance of the bolted joint under transverse loading exhibits different stages, and this agrees well with the results of our previous experimental results. Through the analysis of the force-displacement curves, the characterization parameters for the mechanical properties of the bolted joint can be extracted, such as curve form, tangential stiffness, slip distance, transverse load threshold, etc. The characterization and evaluation of the mechanical properties integrates the process from design to service, which helps to provide reference for the reliability design and performance improvement of bolted joints.