Research On The Basic Mechanism Of Increasing The Buckling Bearing Capacity Of Arch Shell By Radial Inward Movement Of Support

This paper focuses on the arch-shell structure,a large-span space structure system,which is a design structure that meets the requirements of being suitable for large spans,but also has good appearance,material saving,good resistance to load,and has greater engineering applicability.Among them,steel arch and shell structures are increasingly used in large-span engineering examples by virtue of their good load-bearing capacity,less deformation and less damage capability,better stability performance,applicability to large-span spaces,good durability,and reasonable use of the good material strength possessed by the elastic strength amplitude of steel.In this paper,we propose a design method of prestress application,i.e.radial inward shift of bearing,to investigate the basic mechanism of radial inward shift of bearing to improve the buckling bearing capacity and stability of arch shell structure.By conducting load tests on the arch and shell structure,the ultimate bearing capacity test data of the arch and shell structure under the loading test are obtained,and the stress-strain values of the arch and shell structure under the loading test are derived to investigate the stability and bearing capacity performance of the cross arch and shell structure under the pre-stressing action.ABAQUS is used to perform linear buckling analysis and nonlinear buckling analysis with the introduction of defects on the arch and shell structure,to derive the numerical simulation solution of ultimate load capacity,and to investigate the characteristic values and stress performance of the cross arch and shell structure under pre-stress based on ABAQUS analysis.The experimental and analytical data show that the arch-shell structure can improve its load carrying capacity with the application of pre-stress.The theoretical analysis of the arch-shell structure under prestressing is investigated by deriving the expressions and changes of bending moment,axial force and shear force inside the arch-shell structure before and after the radial inward movement of the support based on the force method and elastic center method in structural mechanics.For an actual engineering case,the finite element analysis software ABAQUS is used to analyze the stability,buckling,dynamic performance,self-oscillation and seismic analysis of the arch shell structure,and the numerical simulation data of ultimate load carrying capacity,buckling characteristic value and nonlinear buckling critical load value,frequency,vibration change,collapse ratio and dynamic-static ratio of the arch shell structure are obtained.The stability of the structure is analyzed based on these data.In the performance analysis,the effect of prestressing on the structure was considered and the similarities and differences of various arch and shell structures were compared under the application of prestressing.The results show that the stability of the arch-shell structure is significantly improved when the prestress is applied by radial inward shift of the support,and the flexural critical load value is substantially increased,and the overall stiffness is more uniformly distributed,and the stability is greatly improved,both in the test results for the tension cables at the foot of the arch-shell structure and in the numerical simulation for the radial inward shift of the support at the foot of the arch-shell structure.In the dynamic performance analysis of the arch shell structure,two sets of parameters,dynamic to static ratio and collapse ratio,are used to measure the stability of the structure.The results show that the stability of the arch shell structure under the action of seismic field is improved after the radial inward shift of the bearing,and it has a better effect of resisting the influence of external environment.This paper proposes that the radial inward shift of the bearing can be achieved by using jacking or power traction method to apply prestressing effect,which is simple and convenient.The above research provides a certain theoretical basis for engineering design.