Study On The Dynamic Performance Of Steel-concrete Composite Beams Under Cyclic Loading

Steel and concrete composite structure is a new type structure, and it has been widely used and good rapidly applied in our practical projects.The most significant characteristic of steel and concrete composite structure is fitting steel and concrete two different properties materials together into an organic whole by using shear connectors. Composite structure that designed reasonable can give full play to the tensile performance of steel and the compression performance of concrete, and using traditional construction methods can gain greater economic benefits. At the same time it responses now low-carbon environmental protection national policy and has broad prospects.At present, it has been intensively studied on the structural behavior, failure mechanism and design method of steel and concrete composite structure in the monotonic load at home and abroad, but the studies on the dynamic performance of steel and concrete composite structure in the cycle load are less. Therefore, this paper chooses steel-concrete composite beam that widely used in combination structure as research object, and studies the dynamic performance of steel-concrete composite beam in the cycle load.Research of the dynamic performance of steel-concrete composite beam often needs to adopt the method combining theory analysis, finite element simulation and experimental verification. From the current domestic existing experimental research results, the material, structure form, specimen size and pin connector have large influence on the dynamic performance of steel-concrete composite beam. This paper first makes theoretical analysis on the dynamic performance of composite beam, and then use ABAQUS finite element software to build finite element models and load cycle loads according to the known experimental data. The dynamic performance can be getten, such as failure pattern, hysteresis performance, skeleton curve, stiffness degradation, energy dissipation capacity and the slip between steel beam and concrete slab, and compared with the known experimental results to verify the rationality of the finite element method. Then change concrete material properties, steel bar and steel beam size, pin connector quantity, and research the influences on the dynamic performance of composite beam in cycle load. Finally the composite beams are opened rounded holes to form cellular composite beams, and change hole size and hole pitch to research the influence on the dynamic performance of composite beam. Through simulation analysis on the stress process of composite beams, recommendations are put forward to improve the dynamic performance of composite beams and provide theoretical basis for the seismic performance of composite beams.