Cyclic behavior and mechanical model of a novel endplate connection to double-skin composite wall with slip-critical blind bolts

Abstract

This paper presents an assembled bolted endplate joint for connecting steel beams and double-skin composite walls (DSCWs). The slip-critical blind bolts (SCBBs) were utilized in this novel joint to decrease welding work on-site. In order to investigate the seismic performance of this novel joint, two full-scale beam-to-wall SCBB endplate connection specimens with different design parameters were tested under incremental cyclic loading. Two failure modes of the specimens, namely beam bucking (mode I) and column wall damage (mode II), were finally observed. Analyses of test results indicated that a properly designed SCBB endplate connection with failure mode I could exhibit stable load-bearing capacity and satisfactory energy dissipating capacity. On the contrary, failure mode II should be avoided in engineering due to its unacceptable performance. Finite element models (FEMs) were developed and validated subsequently to further investigate the interior stress and damage distribution. The parametric analysis was also conducted using the FEMs. Based on the experimental results and numerical analyses, an alternative mechanical model was proposed to predict the bending resistance capacity of the column wall. The segmentation method was adopted in the model to eliminate the dependency on a specific pattern of yield line without reducing the accuracy. The reliability of the strength-prediction model of the column wall was validated through the results of the parametric analysis. The design methods and specifications for the components of the joint were finally summarized to make the SCBB endplate connection effectively used in practical applications.