Study On Support Structure And Infilled Wall Effect Of Single-layer Cylindrical Reticulated Shell Subjected To Earthquake

The reticulated shell structure is economical and safe,and is used in large-span public buildings which bear important social functions.In recent years,earthquake disasters have occurred frequently in China.In the 2013 Lushan earthquake,a reticulated shell and a spatial grid structure in the epicenter area suffered severe earthquake damage,which caused domestic and foreign scholars to pay more attention to the seismic performance of space structures.At present,strong earthquake failure mechanism of reticulated shell is still mostly based on independent reticulated shell,through the investigation of actual earthquake damage,it shows that there is a significant coupling effect between the lower support structure and the reticulated shell structure.Therefore,further refinement studies have practical significance in considering the seismic performance of the reticulated shell structure under the support conditions.On the other hand,based on the existing influence of the infilled wall on the seismic performance of the main structure,the infilled wall has a certain influence on the stiffness,bearing capacity and internal force distribution of the structure.In the Lushan earthquake,the infilled wall of the substructure of the Lushan County Gymnasium was partially damaged,and the damage of the upper mesh shell in these areas was more serious.In order to study the influence of the lower supporting and infilled wall on the seismic behavior of the reticulated shell structure,a series of numerical simulation and parameter analysis work were carried out with a single-layer cylindrical reticulated shell as the object.The specific research work is as follows:1.Based on the shaking table test data of single-layer reticulated cylindrical shell,study the finite element modeling methods for the experimental models of reticulated shell with and without infilled wall by using ABAQUS.The shaking table test process was reproduced.The simulated results agree well with the experimental results.The correctness of the modeling method of the reticulated shell structure and the infilled wall is verified,which lays a foundation for the study.2.Finite element modeling of single-layer cylindrical reticulated shell was carried out to study the influence of supporting stiffness on the natural vibration characteristics of the whole structure.Typical examples are analyzed by full load domain dynamic time history analysis method.The failure mode of single-layer cylindrical reticulated shell considering the lower supporting structure under strong earthquake is obtained.It is characterized by the supporting structure's dynamic strength failure of the weakly supported reticulated shell and the shell's dynamic strength damage of the strongly supported reticulated shell.The influences of parameters such as support stiffness and roof quality on the seismic performance of the whole structure are discussed.3.The failure mechanism of single-layer cylindrical reticulated shell with infilled wall under strong earthquakes was studied.The integrated mesh shell model with infilled wall was established by using the integral modeling method.The influence of the infilled wall on the natural vibration characteristics of the reticulated shell structure was investigated.The dynamic analysis of the full-load domain dynamics of the typical example is carried out,and the failure mode of the single-layer cylindrical reticulated shell considering the infilled wall under strong earthquake is obtained,which is the local dynamic strength damage of the reticulated shell and the plastic failure of the wall.It is concluded that the stiffness of the support structure has a significant effect on the plastic distribution of the overall structure.The influence of support stiffness on the ultimate bearing capacity of reticulated shell structure with infilled wall is discussed.