Seismic Design And Characteristics Study Of Concrete Frame Structures With Metal Shear Dampers

In terms of energy dissipation and vibration reduction technology,metal shear dampers are highly favored by construction technicians due to their advantages of full hysteresis curve,high initial stiffness,ability to yield before the structure,and providing a certain degree of stiffness for the upper structure.Moreover,it has little impact on the original structure,is easy to install,can be reused,and has low cost.Therefore,it is widely used in complex,high-rise buildings,bridge engineering,equipment foundations,and other fields,promoting the high-quality development of China’s construction industry during its mature period.However,in current seismic reinforcement,designers often directly determine the number of metal shear type dampers based on personal engineering design experience.This method is inefficient and not rigorous enough.The number,installation position,and connection form of metal shear type dampers also have a significant impact on the seismic effectiveness of the structure.It is necessary to conduct in-depth research on this.In response to the above issues,this article combines YJK software and ETABS software to analyze the seismic reduction technology and characteristics of metal shear damper concrete frame structures.The following are the research contents and corresponding conclusions involved:(1)Summarized the concept and principle of energy dissipation and shock absorption technology;Introduced the performance,practical application,design method research of metal shear type dampers at home and abroad,as well as the application details of YJK and ETABS software;Analyzed the types,structures,performance characteristics,restoring force models,and seismic design and analysis methods of metal shear type dampers.(2)Based on existing seismic design methods and the actual teaching building project of a financial college in Shanghai,a seismic design method based on the reduction rate of interlayer shear force is proposed.Based on the preliminary performance requirements of the structure,a model is established using YJK software to determine the structural reinforcement,and the layout plan of metal shear type dampers is determined based on the proposed design method;Use ETABS software for dynamic time history analysis of structures under frequent and rare earthquakes.The results indicate that the design method of determining the layout of metal shear dampers by reducing the interlayer shear force of the structure by 20% can ensure that all seismic performance objectives of the structure under seismic fortification intensity meet the relevant specifications.This seismic reduction design method provides a quantitative indicator of reducing interlayer shear force by 20% for the seismic reduction design of metal shear dampers,improves design accuracy,and has certain reference value.(3)Based on the above practical engineering examples,the effects of upper support connection,lower support connection,and wall connection on the seismic reduction effect of metal shear dampers were studied.The results show that the top supported metal shear damper provides the maximum additional damping ratio for the structure,which is 4.27% and consumes the most energy;The wall connected metal shear type damper provides the minimum additional damping ratio for the structure,which is 2.77% and consumes less energy.Therefore,in practical engineering,when the economy and construction conditions are good,support type connections can be prioritized to provide more sufficient safety protection for the structure.(4)Based on the ETABS finite element seismic reduction model of a concrete frame structure with a column spacing of 4200 mm,the additional damping ratio of the structure was studied when the wall connected metal shear type damper was moved from the beam end to the middle of the beam span.The seismic reduction performance of the metal shear type damper arranged at different parts of the beam span was studied.The results show that when the connecting wall moves from the beam end to the middle of the beam span,the additional damping ratio provided by the metal shear damper to the structure is the highest,increasing from 0.51% to 2.77%;The trend is gradually increasing,and the additional damping ratio is slowing down within the mid span range of the beam.Therefore,in actual seismic design,metal shear dampers should be set as much as possible in the mid span of the frame.