Influence Of Shear-span Ratio On Static Shearing Performances Of Circular Concrete Filled CFRP-steel Tubes

The research object of this paper is the circular CFRP-concrete filled steel tube.The main purpose of this paper is effect of shear span ratio on the shear-span ratio on static shearing performances of circular concrete filled CFRP-steel tubes,study on bending and shear behavior of concrete filled circular CFRP-steel tube.Circular CFRP-concrete filled steel tube has achieved satisfactory results under other stres forms,but it is not comprehensive.It concentrates on axial compression,compression bending,torsion,compression torsion,bending,and also studies on partial hysteresis and corrosion.It is not perfect that study about shear behavior of both concrete filled steel tube or CFRP-concrete filled steel tube.The study of shear behavior is the foundation to study on complex force,such as compression bending and shearing behavior,compression bending shear and torsion behavior.This research is the basis for the research of the complex research of CFRP-concrete filled steel tube.Firstly,this paper mainly introduces the background,basic components,characteristics and applications of the concrete filled steel tube and CFRP-steel tube concrete,the research status at home and abroad,the significance purpose and the methods of the research,and the main contents.In the following chapters,main content is the study on bending and shear behavior of concrete filled circular CFRP-steel tube.The main methods is experiments,simulation and references.The second chapter is experimental study.The experimental research get shear stress curve,shear strain curve and the failure mode about concrete,steel tube and CFRP tube.The software of finite element simulation in this paper is ABAQUS.Finite element model is built to get shear stress curve,shear strain curve and the failure mode and compared with the experiments.The finite element model of the circular CFRP-concrete filled steel tube is obtained.On the basis of this model,the next part is the the whole process of the bending and shearing behavior.Component of CFRP-concrete filled steel tube is in what state.On the basis of this model,the analysis of whole process based on the third chapter,analysis of concrete cracks,steel yield,longitudinal fracture,transverse fracture,CFRP CFRP maximum bearing capacity steel,concrete,longitudinal CFRP,transverse CFRP of the state.The main parameter is concrete strength,steel yield strength,the number of piles of the transverse CFRP,the number of piles of the longitudinal CFRP,steel ration,shear-span ratio.The main content of the last part is to summarize the future development direction and prospect.The behavior of circular CFRP concrete filled steel tube under bending and shear load is cleared.When the shear-span ratio is small,the the shear deformation is the main deformation.And When the shear-span ratio is bigger,the the bending deformation is the main deformation.The transverse CFRP fracture at the shear zone or the compression zone,and The transverse CFRP only fracture at the compression zone when the shear span is larger.The longitudinal CFRP fracture at the bottom,and when the shear span is larger,the longitudinal CFRP fracture in the middle of the span.Through the analyses of the whole process and the parameter analyses,Various parameters have great effect on the the bearing capacity,stiffness and the shape of the curve.After a large amount of calculation,Bearing capacity equation of vending and shearing behavior is obtained.The research in this paper provides a basis for the study of complex stress state and provides a theoretical basis for practical application of specific engineering.