Finite element analysis and moment resistance of ultra-large capacity end-plate joints

• Finite element models of ultra-large capacity end-plate joints were established and validated by existing test results.
• Influences of end-plate thickness, bolt diameter and bolt layout on the behavior of this joint type were analyzed.
• A yield line model of the end plate in this joint type was proposed.
• Recommendations for configurations of ultra-large capacity end-plate joints were provided.
• A simplified design method was proposed to determine the moment resistance of this joint type.
• The moment resistance obtained by the design method is 75% of the yield moment obtained by FEMs averagely.

The ultra-large capacity end-plate joints, which can be applied in steel structures involving large spans or heavy loads, can provide larger moment resistance than ordinary end-plate joints or large capacity end-plate joints. However, the existing design methods of the ordinary or large capacity end-plate joints cannot be adopted for this new joint form directly because of the inhomogeneous distribution of the tensile loads carried by the bolts as well as the complex stress state in the end plate. Finite element models were built and validated to be reliable using the existing test results. The performance of the ultra-large capacity end-plate joints was analyzed with these models, and a yield line model of the end plate in the tension side was proposed according to the results. Based on the proposed yield line model, a method to predict the moment resistance of the ultra-large capacity end-plate joints was proposed. The moment resistance obtained by the proposed method was compared to the yielding moment of the finite element models, and the proposed method was proved to provide a conservative result which is safe to be applied in the design of this kind of joint.