| Because of the excellent mechanical performance and perfect shape,tubular structures are widely used in space-shells and towers. The research on tube-joints is an interesting topic internationally for the joints'shape diversity and complexity on load properties.At present,there has been full of study on X-type tubular joints'static performance under axial pressure,however, there has been few research on gusset plate to CHS X-joint and also little study on bending stiffness of X-type tubular joints.In this thesis,the finite element method(FEM) is applied to investigate the static performance of X-type tube-joints.The research includes:(1) Ultimate strength of gusset plate to CHS X-joints with the branch tubes under axial pressure.The mechanical performance and failure mode are analyzed by the FEM with the parameters varying.The influence of geometric parameters and axial stress in chord on the ultimate strength are studied.(2) Ultimate strength of gusset plate to CHS XX-joints with the branch tubes under axial pressure.In addition to studying the effect of geometric parameters and axial stress in chord on the ultimate strength,it also explores the influence of load properties and geometric properties with different web loading proportion and angle between gussets.(3) The influence of geometric parameters on the in-plane and out-plane bending stiffness of X-type tubular joints is considered.(4) The effects of geometric parameters, axial stress in chord and load properties of web on the in-plane and out-plane bending performance and ultimate capacity of X-type tubular joints.(5) Through the comparison between the results of FEM and formulars, the applicability of the formulars are investigated. Based on the regression analysis,the formulars of ultimate strength for gusset plate to CHS X-joints and XX-joints are proposed,and also the method of bending stiffness for X-type tubular joints.These formulars'applicability are verified.Finally,further research are discussed. |
PDF Full Text Request