Seismic Response Analysis And Seismic Optimization Of Roof Rail Building Maintenance Unit

With the increase of population,in order to provide more living environment and activity areas,modern buildings are becoming more and more high-rise or super high-rise structures.Thereby,building maintenance unit for the installation,cleaning and maintenance of high-rise buildings have developed faster and faster.Earthquake load is a very dangerous external stimulus.As a typical representative of high-altitude operation machinery,building maintenance unit is located on high-rise or super high-rise buildings,and the impact of earthquakes on the operators who use building maintenance unit and the equipment itself is more serious.Based on the mechanical analysis of the roof rail type building maintenance unit,a set of equivalent seismic load theory based on the parameters of the main structure and non-structural components of the building was established,and the equipment displacement under static load was calculated.These analyses provided a basis for the seismic response analysis of non-structural components.The ANSYS finite element software was used to establish a typical 19-story building model and building maintenance unit finite element model.The modal analysis of the equipment model and the actual seismic wave time history analysis were performed to obtain the maximum displacement response curve of the equipment.The seismic isolation optimization was carried out by adding vibration isolation bearings,which provided ideas for the vibration isolation of mechanical equipment.In this paper,a static analysis was performed on the CWGS250 roof rail Building maintenance unit,which was based on national standards and actual production experience.It mainly included the stability analysis of the building maintenance unit,the strength analysis of the cross arm and the wheel pressure analysis.Then,the counterweight parameters of the equipment were determined,and the results proved that the building maintenance unit model which was used in this paper conforms to national standards and specifications.The Lagrange kinematics equation and the concentrated mass method were used to establish three-degree-of-freedom,four-degree-of-freedom,and six-degree-of-freedom dynamic model of the building maintenance unit.The flexibility matrix was listed according to the flexibility method,the natural frequencies of the above three dynamic models were calculated,the finite element model of the whole building maintenance unit was established,the modal analysis was performed,the first six natural frequencies and mode shapes were extracted,and compared with theoretical calculations and analyzed the causes of errors.In accordance with national standards for earthquake resistance and references,four kinds of actual buildings were used as the object to establish the theory method for seismic check of non-structural components.By comprehensively considering various parameters of buildings and non-structural components,a theoretical method for converting the ground motion data intothe maximum seismic force of the equipment was obtained,and the maximum displacement of the building maintenance unit model under this static load was calculated.The finite element software was used to set a finite element model of a typical building.Then the time-history analysis function was used to load two actual seismic waves,the EI-Centro wave and the Ninghe Tianjin wave.The time-history analysis of the whole building maintenance unit was performed to obtain the maximum displacement position and the displacement time-history curve.By using the method of installing an isolation support,building maintenance unit was seismically optimized,and its displacement curve after the seismic equipment was installed,and its seismic effect was compared and analyzed.These analyses provided some ideas for the seismic design and seismic optimization of non-structural components of buildings.In this paper,based on structural dynamics and finite element theory,the existing models were used to analyze its dynamic characteristics and seismic response,and obtained an effective optimal design for shock absorption.It provides a certain idea and theoretical basis for the seismic response analysis of other types of non-structural members.