Study On The Failure Pattern Of Double Layer Reticulated Shell Structure In Disaster Earthquake

With the progress of the society and the development of the economy,more and more large-span grid structures,such as large stadiums,shopping malls,theaters and warehouses,have appeared in people’s vision,more and more attention has been paid to the seismic research of such structures,when the disaster earthquake occurs,if such buildings can ensure a certain degree of safety,they can become the emergency shelter and emergency center for the victims,so it is particularly important to analyze the seismic performance of the large-span reticle structure under the disaster earthquake.Found in numerous instances of earthquake disasters,rods and nodes of a long-span grid structure fits the characteristics of low cycle fatigue damage,which support node as a connection of roof structure and the lower supporting structure important component,the stress distribution is relatively complex,bearing after damage can lead to upper structure and lower structure from,resulting in the collapse of the whole structure,so to support node under strong earthquake seismic performance research also has the vital significance.Based on the national natural science foundation of China,research on ultralow cycle fatigue performance and evaluation method of bolt ball grid structure under strong earthquake(51578358),the main work of this paper is as follows:(1)the commonly used plate rubber bearing in the spatial grid structure was selected as the research object,and the bidirectional loading device was designed according to the equipment conditions in the laboratory.Under the condition of constant vertical force,the ultra-low cycle fatigue test of the bearing specimen under the horizontal cyclic reciprocating action was carried out.(2)The failure mechanism of plate rubber bearing in ultra-low cycle fatigue test is further analyzed by studying the hysteretic curve,skeleton curve and stiffness curve of the bearing.(3)The double-layer reticulated shell structure of lushan county gymnasium was built in SAP2000,and the dynamic time history analysis was carried out after the input of lushan earthquake real wave.The simulation results were close to the actual earthquake damage by changing the main direction of ground motion and adjusting the stiffness damage value of the members and supports.(4)By the method of incremental step by step forth county stadium doublelayer reticulated shell structure has carried on the dynamic elastic-plastic time history analysis,obtained the displacement response of the structure under seismic action,the plastic hinge development degree and the displacement ductility coefficient,and the structure of the seismic performance analysis,by increasing the structure weak parts of the bar section,the double-layer reticulated shell structure has been optimized,to improve the seismic performance of structure.