Performance-based design method for bolted stiffened end-plate connection under monotonic loading

Abstract

Bolted stiffened end-plate connection is one of the solutions for steel beam to column connections in moment resisting frames implemented after the Northridge and Kobe earthquake incidents. The connection comprises a steel end-plate shop welded to the beam and field bolted to the column flange. In addition, the end-plate extensions are stiffened using angular stiffener plates. Out of the prevailing design codes and guidelines, Eurocode 3-1-8 [1] has provided specifications to design bolted end-plate connections using the equivalent T-stub method, but it does not incorporate the effect of end-plate stiffeners in the design of the connection, whereas AISC [2] design guidelines provide specifications to design the particular connection components. However, these design methods do not address the performance enhancement of the bolted stiffened connection.For these reasons, this study investigates a performance-based design method through numerical analyses to improve the performance of the bolted stiffened end-plate connection. This method is primarily based on the strong column and weak beam concept. Here, primary and secondary yield mechanisms are organized in a hierarchy so that the connection failure occurs in a predefined way by identifying the yield mechanisms and failure modes of the connection. Through this, the targeted performance characteristics of the connection identified as ductility and energy dissipation capacity can be improved. Thus, this performance-based design method is a better approach than the conventional load resisting design method proposed by the code of practice.