Study On Seismic Behavior Of Integral Weaken Energy Dissipation Coupling Beam

For more than half a century,strong earthquakes have occurred frequently all over the world.The damage to the coupling beam of the shear wall cannot be ignored,and it is often easy to cause brittle shear failure prematurely.Based on this,the researchers enhanced the energy dissipation capacity of the coupling beam by changing the form of the coupling beam or adding energy-consuming components.These methods can effectively prevent the brittle failure of the coupling beam,but there are also some shortcomings: the bearing capacity of the coupling beam is significantly reduced after yielding;the coupling beam has a complicated form and construction is difficult;the connection of the coupling beam is prone to occur,after truncation,damages such as slippage and weld cracking.In order to overcome these shortcomings,this paper proposes a non-truncated,integral new energy dissipation coupling beam form: directly controllable weakening of the web section height in the middle of the I-shaped steel coupling beam,so that the deformation is mainly concentrated in the weakened section of the coupling beam in earthquake,and the shear deformation after the weakened section web yields consumes a lot of energy to protect the wall limbs and other parts of the energy-consuming coupling beam from major damage.In order to explore the seismic performance of the new energy dissipation coupling beam,the following researches were carried out in this paper:(1)According to the design purpose of the new energy dissipation coupling beam,the requirements of the energy dissipation coupling beam of the coupled shear wall structure are summarized,and the specific parameter expression of the energy dissipation beam section is proposed;The design formula of the thickness of the end plate of the connecting beam is given.(2)The finite element model of the energy dissipation coupling beam is used to verify the effectiveness of the theoretical design.The results show that the proportion of energy dissipation beam deformation and energy dissipation reaches more than 95%.The discussion and analysis of the parameters of the coupling beam model show that: the energy dissipation beam section shape,size,span ratio,presence or absence of flanges and whether the setting of horizontal stiffeners have a significant impact on its energy dissipation capacity;The length and shape of the horizontal stiffener have little effect on its performance.(3)The optimized design method for the shape of energy dissipation coupling beams is proposed;the performance of the unoptimized and optimized coupling beams is compared through numerical analysis and the theoretical design method is verified.Optimized energydissipation coupling beam has better energy dissipation performance and better low-cycle fatigue performance,the plastic deformation is more uniform,and the cumulative equivalent plastic strain at both ends of the energy dissipation sheet is significantly reduced.(4)The pushover analysis and low-cycle reciprocating simulation analysis of the shear wall structure with steel coupling beam and energy dissipation coupling beam respectively is established by ABAQUS.The comparative analysis results show that the structural failure mode with the energy dissipation coupling beam is energy-consuming section yields before elastic section of coupling beam and wall panels,structural deformation modes stay the same.The hysteresis curve of the structure with energy dissipation coupling beams is full,and the rigidity and bearing capacity are not weakened,and the purpose of equipping the dampers has been reached.