Behavior and Design of Ultra-Large Capacity End-Plate Bolted Connections

Abstract

Bolted end-plate connections are classified according to their flexural resistance and rotational stiffness. The moment resistance of any connection is controlled by its different components (end-plate thickness, bolt diameter, bolt grade and existence of stiffeners (if any)). The architectural requirement for achieving optimum clear height in floor without increasing structural beam depth leads to use of wide flange beams with smaller depth. To transfer end moments of shallow beams, ultra large capacity end-plate connection (12 to 16 bolts around tension flange) must be used. Increasing the number of bolts in the tension zone results in a higher moment resistance for the connection. In this thesis, ultra-large capacity connection with 12 bolts in tension zone (4 bolts per row) is studied. Behavior and design of this type (4 bolts per row) has not been included in any international codes yet. Due to the complicated behavior in end-plate and bolt force distribution among bolts, non-linear finite model is utilized to investigate these connections and a parametric study is conducted. This parametric study is carried out on both flushed and extended configurations using different material and geometric parameters such as: end-plate thickness, bolt diameter, effect of horizontal stiffeners and their thickness, bolt grade, steel grade and beam depth to investigate their effect on the moment resistance of the connection. Moreover, bolt force distribution is studied for different connection configurations at yielding and ultimate limit of bending moments. Results revealed the effect of the chosen parameters on the connection moment resistance as well as bolt force distribution among the bolts. Finally, a simplified design procedure is proposed with recommended configurations to achieve the most economic design. Conclusions are summarized and recommendations for future researches are listed at the end of the dissertation.