Study On Seismic Performance Of Lead Viscoelastic Damping Structure Under Mainshock-aftershock

In order to solve the problem of insufficient energy dissipation capacity and collapse resistance of the traditional seismic structure under the ground motion of the main and aftershock sequences,the lead viscoelastic damper is used to reduce the seismic design of the structure to improve the seismic performance of the structure under the main and aftershocks.The Open Sees numerical simulation method was used to conduct a systematic study on the seismic performance,energy dissipation capacity and collapse resistance of the lead viscoelastic damping structure under the main and aftershocks.The main research contents and conclusions are as follows:(1)The design and modeling of 6-layer reinforced concrete seismic frame structure(RCF)and lead viscoelastic damping structure(LVDF)are relatively reasonable,meet the requirements of China's current codes,and the dynamic responses of the two are relatively close;(2)The construction method of the main and aftershocks seismic sequence working conditions based on China's specifications is proposed,and the seismic performance of the RCF structure and the LVDF structure under the action of each main and aftershock sequence working conditions is analyzed.The research shows that the LVDF structure can reduce the structure under the main and aftershocks.The average and dispersion of the interlayer displacement angle of each layer;the LVDF structure has better vibration control effect.The maximum interlayer displacement angle of each layer under the main aftershock and the maximum interlayer displacement angle of the structure are reduced by about 30% and 25% on average compared to the RCF structure;(3)The energy dissipation mechanism of the RCF structure and the LVDF structure under each main and aftershock ground motion is studied,and the plastic hinge rate of the structure,the energy consumption of the structural members,the energy dissipation ratio of the structural members and the structural yield mechanism of the structure are compared and analyzed.It shows that the lead viscoelastic damper consumes more than 30% of the ground motion input energy,delays the appearance of structural plastic hinges and reduces the damage degree of the structural members,and alleviates the adverse effect of the ground motion sequence of lower ground motion strength on the structure damage degree;(4)The incremental dynamic analysis and seismic vulnerability analysis methods were used to evaluate the collapse resistance of the LVDF structure under the action of the main shock only.The research shows that the CMR value of the collapse resistance reserve coefficient of the LVDF structure is increased by about 14% compared to the RCF structure.The standard deviation of the collapse resistance of the LVDF structure is reduced by about 6% compared to the RCF structure;(5)The LVDF structure was subjected to incremental dynamic analysis of the aftershocks in each mainshock damage state,and the structure 's ability to resist aftershock collapse was evaluated.The research shows that after experiencing the same mainshock damage,the LVDF structure still has a height of about 10 higher than that of the RCF structure.% Resistance to aftershock collapse;LVDF structures still have good residual aftershock collapse resistance under high mainshock damage,and can reduce the adverse impact of high mainshock damage on the structure's resistance to aftershock collapse.