Study On Bending-torsion Mechanical Properties Of Recycle Concrete-Filled Circular Steel Tube Members

Scholars at home and abroad research for the recycled concrete filled steel tube structure is limited to simple static research,combination of complex stress involved rare under load,limit the practical application of recycled concrete filled steel tube components,and recycled concrete filled steel tube bend torsion science research to study the performance of its component in pressure-bending-cut-twisting composite stress case studies play an important role.Therefore,this paper studies the flexural and torsional properties of recycled concrete with circular steel pipe as the research object.The main research work is as follows:In this paper,finite element software simulation analysis method is used for research,referring to the existing flexural and torsional performance test of recycled concrete members of circular steel pipe,ABAQUS model is established,and the accuracy of the model is verified by coMParison with the test results.Based on the test and finite element model analysis,the whole process of bending and torsion performance of the component is analyzed,and it is found that the entire load curve of the component can be divided into three stages:? elastic section O-A;? elastoplastic section A-B;? plastic strengthening section B-C.Then,the finite element software ABAQUS was used to study the stress morphology of steel tubular recycled concrete members,and the cloud diagram of the members under different bending and torsional ratios and the cloud diagram of the members under different concrete substitution rates were analyzed.Affecting the recycled concrete filled steel tube bending torsional component learning parameters are analyzed,and the performance of the recycled concrete replacement,crankle ratio,steel ratio,strength of steel pipe on the influence law of the bend torsion learning performance,found to improve the ultimate bearing capacity of the steel tube recycled concrete component,the initial stiffness of the most effective method is to improve the components of the steel tube wall thickness steel ratio,the compressive strength of concrete cube component of each index,the bigger the steel yield strength,ultimate bearing capacity,yield strength and elasticity of the artifacts the length,the greater the crankle ratio is larger,the ultimate bearing capacity of the artifacts,yield load and elastic length,the lower the initial stiffness,Moreover,it has obvious influence on the final displacement of the component.The larger the flexural torsional ratio is,the more the component will be bent.With the increase of section diameter,the ultimate bearing capacity,yield load,elastic length and initial stiffness of members will be significantly increased.Among all the factors,the section diameter of the member has the greatest influence on the mechanical properties of the member.Since the mechanical properties of concrete-filled steel tube members and reccycled concrete-filled steel tube members are basically the same,this paper proposes a practical calculation method for the flexural and torsional capacity of reccycled concrete-filled steel tube members by referring to the formula for the flexural and torsional properties of reccycled concrete-filled steel tube members,and verifies the practicality and accuracy of the formula.