Behavior of eight-bolt large capacity endplate connections

Only a limited number of experimental and analytical reports exist concerning large capacity, eight-bolt, extended endplate connections. This paper describes the structural properties, both stiffness and strength, of an extended endplate connected to a column flange, with no stiffeners in either tension or compression region, using eight high strength fully and partially prestressed bolts. The case studies considered in this paper offer greater insight into the significance of endplate and column flange interaction and bolt positioning; besides the displacement and stress distributions, the prying phenomenon is also addressed. The methodology is based on a finite element modeling developed previously for the standard four-bolt array. ANSYS, version 4.4, a large-scale general purpose code is selected for equivalent three-dimensional (3D) analysis. The end-plate, beam and column flanges and web are represented as plate elements. Each bolt shank is modeled using six spar elements. 3D interface elements are used to model the boundary between column flange and back of the end-plate that may make or break contact.