Experimental study on the shear behavior of friction connections with corrosion damage

Abstract

Corrosion effects on the shear behavior of friction connections are experimentally investigated in this paper. Based on ultrasonic technique, double lap friction connections were firstly assembled and accurate preloads were applied on high-strength bolts. Electrochemical accelerated corrosion method was employed to achieve four corrosion levels of specimens. Tensile test was then conducted on the corroded specimens and a finite element model was also established to make a comparison with test results. The study shows that net cross-section failure occurred for all the specimens and no obvious reduction of bearing capacity was found for corroded connections within 10% weight loss. Two slippages occurred during loading and finite element analysis shows that the second slip displacement is caused by slippage between washer and bolt head/nut. For friction connections with four corrosion levels, slip factors firstly increased and then gradually decreased with increase of the corrosion degree, and a prediction model of frictional resistance of the friction connection was proposed. Contact analysis of interfaces between plates accounts for the distribution of corrosion damage on the inner plates. Load-displacement curves obtained from finite element model agree well with test results. Corrosion effects on the bearing capacity of the friction connections were analyzed as ultimate load increases when slip factor or bolt preload increases.