Influence Of Roofing System And Suspended Equipment On Static And Dynamic Performance Of Single Layer Spherical Reticulated Shell

With the good mechanical performance and beautiful shape,spherical reticulated shell structures are often used in large-scale public buildings such as stadiums,opera houses and convention and exhibition centers.It is often a landmark building in the area where it is located and has an important social status.In terms of composition,the spherical reticulated shell structure mainly includes the main structures and a large number of roofing system and suspended equipments attached to the surface and inside.These components in the roofing system and suspended equipment may significantly affect the static and dynamic performance of the main structure.Although scholars at home and abroad have carried out systematic researches on the static and dynamic performance of spherical reticulated shell,obtained fruitful theoretical achievements,the influences of roofing system are generally ignored in the researches;on the other hand,many spherical reticulated shell structures have important social functions such as transportation hub,disaster shelter,and the internal personnel are relatively dense.Under the action of disaster load,the nonstructural components such as suspended equipments inside the spherical reticulated shell structures may bear serious damage or secondary disaster,caused the interruption of the whole building function.Therefore,it is of great social significance and engineering application value to study the response and failure mechanism of the spherical reticulated shell structure with roofing system and nonstructural components such as suspended equipments under static and dynamic loads,and establish reliable design method for spherical reticulated shell with roofing system and suspended equipment.The researches on nonstructural components has become a hot topic in the frontier theoretical research of civil engineering.At present,the researches on nonstructural components in buildings mainly focuses on multi-storey and high-rise buildings,while the research on the performance and influence of suspended equipment in long-span spatial structures are relative minor.Therefore,this paper selects the most typical nonstructural components of spherical reticulated shell structure,studies the influence mechanism of roofing system on the static stability and seismic response of spherical reticulated shell structure,studies the strong earthquake influence mechanism when heavy equipment is suspended on spherical reticulated shell structure,and established the calculation method of seismic action of nonstructural components such as suspended equipment in spherical reticulated shell structure.The research contents are as follows:(1)Researches on static stability experiments and numerical modeling method of the spherical reticulated shell with roofing systemThe static loading tests of the spherical reticulated shell structure model with bolted purlin roofing and welded purlin roofing system are carried out to investigate the influence of different roofing systems on the static stability of the shell.Through monitoring the strain datas of roofing system and the shell members,and combining with the failure mode of experimental model,the influence of each component on the bearing capacity of the shell are analyzed;the equivalent method of each component connection and roof panels are studied,and the established finite element analysis model which considered the influence of roofing system,then,the correctness and feasibility of the model are verified through experimental researches.(2)Researches on static stability of spherical reticulated shell structure with roofing systemBased on the above finite element modeling method of spherical reticulated shell structure systems with roofing system,the static stability simulation analysis of spherical reticulated shell structure with bolted connection and welded connection purlin roofing system are carried out respectively.The influence of roof system is analyzed from the static bearing capacity of spherical reticulated shell structure,the development and distribution of plastic members and the failure mode of spherical reticulated shell structures.The Influence mechanism of roofing system are studied by the internal force of spherical reticulated shell members and the buckling of purlin joints.The influence of different parameters(span,rise span ratio,purlin joint strength and stiffness,pillar height,roof load,the imperfection amplitude and mode of spherical reticulated shell and roof system)on the static stability of spherical reticulated shell structure with roofing system are analyzed.The influence range of roofing system on the static stability bearing capacity of spherical reticulated shell structure.(3)Researches on seismic response and strong earthquake failure mechanism of spherical reticulated shell structure with roofing systemIn order to study the influence of roofing system on the seismic response and failure mechanism of spherical reticulated shell structure under strong earthquake,the modal characteristics of the finite element model of spherical reticulated shell structure with roofing system are analyzed.Through the failure mode analysis of spherical reticulated shell,the influence of the roofing system on the seismic performance of the spherical reticulated shell structure are obtained;through the analysis of the yield of purlin joints and the energy consumption of the roofing system components,the influence mechanism of the roofing system on the seismic responses of the spherical reticulated shell structures are revealed,and the influence regulation are obtained through the studies of different spherical reticulated shells and roofing systems(span,rise span ratio,different seismic loads,purlin joint stiffness),the seismic damage models of spherical reticulated shell structure with roofing system are established.(4)Research on acceleration response spectrum and seismic action of suspended equipment of spherical reticulated shell structure.The acceleration responses of spherical reticulated shell joints under seismic load are compared with the seismic action of nonstructural components in the current seismic design codes at home and abroad.The acceleration response spectrum analysis of spherical reticulated shell joints in elastic stage under seismic load are carried out.The calculation formulas of acceleration response spectrum in three directions of spherical reticulated shell joints under three-dimensional seismic load are derived and analyzed.The calculation methods of seismic action of nonstructural components such as suspended equipment in spherical reticulated shells with bolted and welded purlin roofing system are given respectively for spherical reticulated shell with different span and rise span ratio.(5)Researches on seismic performance and failure mechanism analysis of spherical reticulated shell with heavy suspended equipmentThe modal analysis of spherical reticulated shell structure with large mass suspended equipment are carried out,and the influence characteristics of suspended equipment on the displacement response of spherical reticulated shell joints under earthquake are analyzed by the displacement response differences of each ring node of spherical reticulated shell structure with suspended equipment.Based on the analysis of the proportion change of plastic members in spherical reticulated shell structure with heavy suspended equipment under strong earthquake,the influence mechanism of heavy suspended equipment on the failure of spherical reticulated shell structure are revealed.Two typical failure modes of spherical reticulated shell structure with heavy suspended equipment are defined.The influences law of different parameters(span,rise span ratio,defect amplitude,different seismic load and length of suspended)on spherical reticulated shell structures with heavy suspended equipment are analyzed.