Study On Mechanical Properties Of Intersectional Stress Elements For Long-Span H-Section Steel Truss Structure

With the rapid development of high-speed railway in our country, a large number of passenger stations have been constructed, as well as the construction of steel structure secured a golden development period, meanwhile, various types of steel structures have been widely used in the railway stationBased on the intersectional stress element used in Cross-layer overloaded plane truss of H-beam in passenger station structure, pseudo-static test was carried out on a1/4scale model. Afterward the mechanical properties of intersectional stress elements, which include ten kinds of strengthening measures, are analysized via the finite element numerical simulation.. The main contents and conclusions of the thesis are as follows:In order to study the actual failure mode and mechanical properties of the key positions, the scale model test of intersectional stress elements was carned out via low-cycle reverse loading. The test shows that, for the intersectional stress elements, the tensile failure first occurred in the downside diagonal rod of non loading end and the weld in connection position at the end of the node hub. Then it occurred in the connection position of hub edge, which was located in the upper part of the middle montan。 However there was not any buckling through the whole process. It indicated that the welding quality of intersectional stress elements had a great effect on mechanical properties in actual engineering, therefore, it was necessary to guarantee the welding quality and take reinforcement measures.The finite element numerical simulation was caried out to study the mechanical properties of intersectional stress elements. In order to simulate the actual stress state of intersectional stress elements more realistically, based on the test model and the restriction in the surrounding members was considered,*shape and■shape model were selected as the up and down threshold of their mechanical properties. Then a total of10models, which included original model of*shape, flitch model, reinforced flitch model1, reinforced flitch model2, cover plate model, sleeve model and original model of Oshape, flitch model, cover plate model, sleeve model, were anglicized. The results shows that under different reinforcement measures, the maximum effective stress all focused on end of the loading rod, and the intersectional stress elements were destroyed as soon as the loading rod was failure with tension. In addition, the load-bearing and energy dissipation capacity of■shape model were much better than the*shape.Compared with the results of finite element numerical simulation and test, a reasonable and effective reinforcement measure was put forward, actually it can be taken as a reference for practical use.