Study on bearing capacity of hollow ball nodes welded in space grid

welding hollow balls;  finite element analysis;  bearing capacity;  Mechanism of destruction

For the welded hollow ball joints, the ANSYS 9.0 program was used to simulate and calculate the bearing capacity, and the elastic-plastic stress and deformation distribution law of the shell surface when the ball nodes were tensile and compressed, and the exact position of the failure zone area in the spherical shell was determined. According to the tensile failure mechanism of welded hollow ball joints, a three-dimensional stress state analysis model of plastic failure failure of ball joints is proposed. Furthermore, the ultimate force analysis under the complex stress state of sphere-weld-steel pipe was studied. The limit state calculation theory is applied to obtain the calculation formula of the tensile bearing capacity of welded hollow ball joints. Based on the discussion of the compression failure mechanism of hollow ball nodes and the statistical analysis of experimental data, the calculation formula of the compressive bearing capacity of ball nodes is obtained by linear regression method with several variable parameters. The data results show that the calculated value of the obtained hollow ball node bearing capacity formula and the experimental value are well fitted.