Seismic Performance Of Prefabricated Beam-to-column Connection With Hinge And Energy-dissipating Plates And The Weak Beam Strong Column Frames

Earthquake is one of the worst natural disasters that human beings face. Due to its strong randomness, unpredictability and wise-range involvement, earthquake seriously threatens the survival of humans and development of the society. In recent years, many building structures are heavily damaged under seismic action, causing serious casualties and economic losses. Beam-to-column connections play a crucial role in the seismic performance of multi-story steel frames. People have been seeking for effective beam-to-column connections which have preferable ductility and dissipative capacity. For some special buildings, people even want them to be available after rare earthquakes through simple repair.On this background, an innovative prefabricated beam-to-column connection with hinge and energy-dissipating plates is put forward in this program. The design of this connection is carried out in the following thoughts: firstly, the beam is connected to the column with a hinge which could rotate and bear the vertical load; secondly, the hinge would be beset by steel plates which provide the connection with bending resistance ability. The parameters of the connection can be adjusted easily for the connection is independent with other members of the structure. And then the expected performance of structures under rare earthquakes can be easily controlled: the deformation and energy dissipation would be concentrated in the steel plates of the connection; other members of the structure would remain elastic. After rare earthquakes, the function of the structure would recover quickly just by replacing the steel plates around the connection. The following issues are investigated in this thesis:(1)Based on the thoughts above the mechanical design of the innovative connection is carried out and steel plates of four kinds of cross sections are considered. The numerical models of the connection are developed using the finite element analysis software ABAQUS, and the finite element analysis of the connection under monotonous displacement load and cyclic variable amplitude load is carried out. The deformation, the stress and strain, the deterioration of stiffness and strength, the capacity of energy dissipation and the fatigue performance of the connection are studied.(2)Based on the result of finite element analysis, pseudo static tests and fatigue tests of connections with steel plates of three different kinds of cross sections are carried out. Through the analysis of test phenomena and hysteretic curve obtained, the deformation, stiffness, strength and capacity of energy dissipation are studied. The fatigue performance of the connection is investigated and proved to be good through the fatigue test.(3)By comparison of the connections with steel plates of different cross sections and with consideration of assembling ability, the connection with “U” steel plates is optimal. Based on the small-deflection theory and finite deflection theory of thin plates, the restoring force model of the connection with “U” steel plates is proposed. A three-story steel frame structure is designed and through the static nonlinear analysis and dynamic nonlinear analysis the expected performance of structures using the innovative beam-to-column connection is realized.