Bearing Capacity Analysis Of Concrete-partial-filled Steel Box Continuous Composite

The steel-concrete composite beam combines the two materials of steel and concrete to form a new structure of double combination effect,can better use of steel materials,high tensile strength,light weight,good seismic performance,etc.,but also consider the concrete material has a large compressive strength,good integrity,ease of construction and so on.While the composite beam in the middle bearing in a relatively unfavorable state that wing plate is pulled and steel beam is compressed,the wing plate is subjected to tensile stress and easily lead to cracking of the concrete,steel beam under tensile stress and prone to local buckling phenomenon,thus affecting the durability,flexural rigidity,reduce its carrying capacity.In order to improve the bearing capacity of the negative moment region of the middle bearing,a concrete-partially-filled steel box continuous composite beam is put forward.The longitudinal reinforcement of the wing plate in the support area plays an important role in the development of the concrete crack,the core concrete filled in the steel box improves the local buckling ability of the steel box web,and participates in the bending and shearing action.In the middle bearing section,by increasing the reinforcement ratio of the wing plate and filling the core concrete in the steel beam,so that the continuous composite beam has higher bending rigidity,better local stability and deformation ability.In this paper,through the experimental study on the mechanical performance of six concrete-partially-filled steel box beam continuous composite beam,combined with experimental results,theoretical calculations and ANSYS finite element simulation analysis,it has a deep understanding of the moment amplitude modulation,flexural bearing capacity and the development of concrete wing cracks in continuous composite beams middle bearing area.(1)Through this test,description of the test beams wing plate steel box girder concrete crack development,local buckling,plastic hinge formation and deflection test phenomenon during the loading process,and analyzes the phenomena and causes of the experiment.(2)In the analysis of the different force ratio influence on internal force redistribution in the continuous composite beam middle bearing section,deduces the bending,shear bearing capacity and consider the concrete shrinkage stress of cracking moment of theoretical calculation formula in the middle bearing negative moment region.(3)According to the calculation formula deduced in this paper,the experimental data and the calculated values are compared and analyzed.It is found that the data between the two are in good agreement with each other,which is great significance to the study of the bearing capacity and the crack load in the continuous composite beam.(4)Through the ANSYS finite element simulation of the test beam,the finite element calculation were compared with the experimental values,found that changes in the process of stress trend of two data is consistent,that the finite element model of the establishment is accurate and reliable,able to reflect the real situation of continuous composite beams during the test,the actual stress state and characteristics.