Effect and evaluation of prying action for top- and seat-angle connections

Abstract

Nonlinear finite element (FE) static analyses of top- and seat-angle connections were performed using ABAQUS standard to investigate the influence of connection parameters and its properties on prying action developed due to the interaction between column flange and top angle’s vertical leg. Contact phenomenon between two interfaces with finite sliding and bolt pretension in the initial step of analysis was considered in the FE model. FE analysis results were compared with the experimental ones to examine the applicability of the FE model. Then, the location of plastic hinges in connection assemblages was investigated at the ultimate state of the connection and a parametric study was performed varying connection parameters, material properties of connection assemblages, and magnitude of bolt pretension to visualize their effects on prying force and on the position of prying force on top angle’s vertical leg. Current study shows that plastic hinges not only develop at top angle’s heel and bolt hole region but also in the bolt shank that differs from some assumptions of power model (Kishi and Chen 1990): (1) top angle thickness and gage distance from angle heel to bolt hole center line have an distinct effect on prying action; and (2) distributed prying force developed near the region of the top edge of tension angle’s leg adjacent to column flange can contribute to the failure of the connection. Finally, a mathematical formulation to identify the location of prying force action point is proposed.