Numerical Study of the Preload Force Loss of Corroded High- Strength Bolts

Abstract

Corrosion significantly affects the structural behavior of members in a connection (i.e., the preload force of bolts, the thickness of steel plates, and the anti-sliding friction of steel plates). The preload force of bolts is a key factor affecting the bearing capacity of high-strength bolts shear connections, and it will be significantly influenced by corrosion. In this study, the preload force loss of high-strength bolts shear connections after corrosion is studied. A finite element model validated by previous experiment is developed for estimating the preload force loss of high-strength bolts after corrosion. The value of the preload force loss of corroded highstrength bolts increases as the corrosion rate, but the effect of steel grade on the preload force loss is not obvious. Based on the results of finite element analysis, a degradation model for predicting the preload force loss of corroded high-strength bolts is suggested, and the degradation model agrees well with various test data. The results of this study can provide a reference for safety assessment of corroded high-strength bolted shear connections.