Study On Seismic Performance Of New Combination Tube Node

Based on the excellent performance of steel and polyurethane, a new composite structure which polyurethane material is poured into steel tube is formed, namely steel-polyurethane sandwich composite structure. This composite sandwich steel node has a good carrying capacity, ductility, energy dissipation capacity, stability and other properties.The main contents are as follows:(1) Based on the theoretical study of composite structure, a nonlinear constitutive model of polyurethane and the steel- polyurethane bond model are introduced, combining steel- Polyurethane node working mechanism, the finite element analysis of the steel-Polyurethane Sandwich tube node is obtained in this paper.(2) Using the finite element method, maximum stress,stress distribution pattern, the basic work processes is got and capacity, deformation, energy dissipation, stiffness degradation,failure mode are analyzed.(3) According to the finite element analysis results, considering the hollowness, the node type and other factors, 9 node specimens which through different thickness polyurethane get the different hollowness and corresponding loading scheme are designed. K, T, Y type tube node are used which the polyurethane sandwich thickness, steel thickness are consistent with the others. By the cycle load test, the mechanical properties and the main factors are studied, the hysteresis curve, mechanical properties and failure mechanisms are got. The test key research the influence of the different design factors on failure mode, capacity, ductility, energy dissipation, stiffness degradation.(4) On the basis of analysis of experimental and theoretical results, finite element analysis model and the method are optimized and the parameter analysis is conducted. The failure mechanism and the effects of relevant parameters are studied, appropriate measures for the construction and design of countermeasures are proposed.The seismic performance study of new combination tube node can broaden the research field of combination tube node, enrich its content, and provide theoretical and experimental basis for the structure practical application.