Nonlinear Finite Element Analysis Of Cast-Steel Joints In Pipe Truss And Research On Some Correlative Problems

With the advantages of lightness, beauty and lower steel consumption, steel tubular structures have got a quick development and wide application in China. Cast-steel joints applied to the civil engineering by designers represent many advantages such as beauty, freely design and safety. Because the criterion which can direct the cast-steel joints'designing has not been formed in China presently, researches on cast-steel joints mostly by the aid of finite element analysis software and tests.Firstly, by the aid of finite element analysis software—ANSYS, the writer analyzes the cast-steel joints designed in the center of Exhibition and Sport in Nantong, and makes some evaluations for those working state. According to the stress of the key points on the cast-steel joint, the writer observes its working state under the most disadvantage designing load, and traces the full loading-displacement path, then calculates the joint's ultimate strength. In the process of analysis, the writer finds the cast-steel joint will form a weak zone at the connection with the steel tubes, strengthens the zone with some conformation measures which can improve the working state and the safety of the joint.Secondly, under the change of various geometric parameters , the writer analyzes the cast-steel joint with the measure of inelastic large stress finite element analysis, and observes the connection of the joint's ultimate strength with geometric parameters. It is proved that if designed reasonably, the multi-tubular cast-steel joints only yield to axis force with one tube. The fracture forms of crushing and excessive deformation due to the pulling and pressing of the branch tube can be avoided, which can improve the safety of the structures.Finally, by comparing the finite element analysis with the results of tests, the dependability of the finite element analysis which the writer uses is validated.