Static Behaviour Of Ultra-large Capacity End-plate Connections In Steel Structures

Bolted end-plate connection is widely adopted in steel structure design. Researchers from domestic and abroad have conducted elaborate and intensive investigations on the performance of conventional end-plate connections. While in some modern steel structures, conventional end-plate connections can not meet the capacity requirements which are improved. End-plate connections with special configurations are needed, including large capacity end-plate connection and ultra-large capacity end-plate connection. The latter configuration is arranged16high strength bolts near tension flange of beam. While few researches have been done upon the behaviour of the end-plate connections with special configurations mentioned above. In this dissertation, experimental research, finite element calculation and analysis have been carried out to study the static behaviour of ultra-large capacity end-plate connection. The main scope of this dissertation includes:Firstly, research progress of traditional configuration and large-capacity end-plate connection are presented. Design methods in accordance with domestic and international specifications for end-plate connections are compared. Shortcomings of exsiting research are also reviewed.Secondly, aiming to investigate the static behaviour of ultra-large capacity of end-plate connection, an experimental research of monotonic load has been carried out. The loading capacity, rotational stiffness, deformation feature and variation of tension force in bolts are analysed subjected to different end-plate thickness and bolt diameter.Thirdly, the general-purpose finite element package, ANSYS, is adopted to analyze the specimens of the monotonic loading experiment with improved process to build three-dimensional finite element models. The finite element analysis (FEA) is a valid method against the experimental results. Loading capacity, deformation ability, variation of tension force in bolts, end-plate and extended stiffener mechanical characteristics in subjected to ultimate bearing capacity are investigated in detail. Moreover, FEA can cover the shortage of the available measuring technique and acquire some characteristics which are not measured easily by tests.At last, an investigation on the tightening sequence and the strain relaxation of high strength bolt during the construction of all the ultra-large capacity end-plate conneciton specimens are provided. Pretension terminal value with different tightening sequence are compared and monitored more than65hours. A detailed tightening sequence, the final value of strain relaxation and the torque check during construction have been recommended due to the contrast and monitoring results.