Study On Stress Of Node Of Concrete Filled Steel Tubular Of Houhu Cable-stayed Bridge

In recent years,the concrete filled steel tube(CFST) is adopted for more extensive in the global scope.Because of combining with the advantages of both steel and concrete,it is high of load-carry capacity,good at plasticity and malleability,easy to execute and construct,excellent in fire resistance,economic efficiency is good economy and so on.As a result of its special advantages and in-depth researching,the researchers found that the combination of reinforced concrete column and the CFST which called node is the most complex and unsubstantial part of structure.It is the key part of the structure calculating model,structure designing and construction.Furthermore the complexity of the joint structure is very important for cost structure.Study out a definite reasonable mechanism, manufacture and installation node of CFST is the critical process for promoting CFST structure.The theory of designing CFST component is becoming more and more mature,but the theory of node designing is not uniform yet in domestic,so it is necessary to do a further research and analysis to understand the work mechanism of node and make sure of security of different structure joints structure.The tower of Houhu Bridge in Huangpi District of Wuhan uses the circle-end CFST. The methods and measures is not involved in the design and construction in this shape transformation.According to the measured data and finite element analysis,this article carries on the analysis of stress of node of the combination of reinforced concrete column and the CFSTFirstly,this article introduces the emplaced scheme of the sensor and the load cases in the construction of Houhu Bridge's tower,the load cases are divided into axial compression case and eccentric compression case so as to analyze the mechanical behaviors of node of the circle-end CFST.Secondly,an ANSYS model of finite element analysis was established considering various factors and assuming reasonable unit and material constitutive relation to calculate and exact the stress of node and then compare theoretical data with measured data.The result proves that the theoretical data is consistent with the measured data which can lead us to analysis the most unfavorable conditions and the change tendency of the node of circle-end CFST.Lastly,stress of node of the tower was compared in order to accurately analysis the differences between sub-model and rough model by establishing the sub-model of node under Saint Venant's principle.Variation rule and the most unfavorable position of stress of node of the circle-end CFST.was found out based on the measured data,the simulation calculation.then the insufficiency of theoretical analysis and experiments were put forward and suggestion was given to the post researchers.