Ultimate tensile behavior of bolted T-stub connections with preload

Abstract

This paper experimentally studies the ultimate tensile behavior of 16 bolted T-stub connections and 2 bolted angle counterparts, regarding horizontal plate thickness, bolt diameter, bolt pitch, and bolt preload. The experimental results are discussed in detail and validated by finite element models. The results show that three failure modes were observed in the specimens, namely bolt fracture with yielded T-stub, T-stub fracture close to the heel and T-stub fracture close to holes line with yielded bolts. Except for the horizontal bolt pitch, the bolt diameter, horizontal plate thickness and longitudinal bolt pitch have a positive correlation with the bearing capacity of the connection. Increasing the bolt diameter and horizontal plate thickness would increase the initial stiffness of the bolted T-stub connection, whilst increasing the bolt pitch has the opposite effect on that. The ultimate displacement of the connection would be improved by increasing bolt diameter and bolt pitch whilst horizontal plate thickness is suggested to match with bolt diameter. Bolted angle connection exerts better deformation ability, but less initial stiffness and bearing capacity than the bolted T-stub connection. The finite element parametric analysis shows that the horizontal plate thickness has greater influence on the connection performance than the vertical plate thickness. Based on the plate-shell theory and component method, the prediction methods for the initial stiffness and tensile capacity of the bolted T-stub connections with or without bolt preload are derived. The theoretical calculation results are in good agreement with the experimental results.