Finite Element Analysis Of Steel Reinforced Concrete Mega Column On Influencing Factors

With the development of economy and the progress of technology,China has become one of the countries which have the largest number of high-rise and high-rise buildings,and the development of high-rise and super-high-rise buildings is reflected in lots of aspects,such as wider application,higher height indicators,more innovative features,more complex facade design,greater use of the area,etc.The mega structure system is coming into being and developing rapidly in such a situation.As the main structural component of the mega structure system,the mega column not only bear the horizontal load of wind and earthquake,but also bear the huge vertical load,so the force performance of the mega column is essential for high-rise and high-rise buildings.In this paper,according to the different influencing factors of SRC Mega column including concrete strength grade,steel content in section steel,reinforcement ratio,volume matching ratio,axial compression ratio and shear span ratio,using the finite element software ABAQUS for numerical simulation analysis.The influence of each factor on the performance of SRC mega column was analyzed,and finally,the corresponding laws are explored to provide some reference on actual engineering design.In this paper,the main content is as follows:(1)In the finite element software ABAQUS,the standard SRC mega column model is established by selecting the length of the calculation,selecting unit,the division of the network,selecting the assembly of the parts,the defining the contact surface,applying the load and selecting the calculation method.Through a large number of trial analysis,different parameters are set more scientifically and reasonably.(2)Based on the control variables method,considering the influence factors such as the strength grade of the concrete,the steel content,the reinforcement ratio,the stirrup ratio,the axial compression ratio and the shear span ratio,models are respectively established to analyze.By studying the effect of different factors on the load-displacement curve,the peak load,the peak displacement and the equivalent stress cloud of the parts of SRC Mega column,the effect of different influence factors on the performance of SRC mega column is analyzed.Meanwhile,by studying the the strain distribution on the maximum stress cross-section under the peak load,the plane-section assumption which is used in numerical simulation with ABAQUS is verified.(3)For the high-strength materials which are widely used in SRC mega columns,such as high-strength concrete and high-strength stirrups commonly,the influence of them on mechanical properties of SRC mega columns is analyzed,and the size effect problems risen from large sectional dimension of SRC mega columns is analyzed.Modifying the constitutive model of the concrete,the effect of the size effect on the SRC mega columns is studied.The results show that the influence of steel content,axial compression ratio and shear span ratio of SRC mega column on the mechanical properties of the components is the greatest.Improving the steel content and shear span ratio of the components and reducing the axial compression ratio could improve the ductility of the component;improving the steel content and axial pressure ratio of the component and reducing the shear ratio of the component could improve the bearing capacity of the component;when the axial compression ratio or the shear span is relatively large,or when the component is in the elastic stage,the deformation of the cross-section can better meet the flat cross-section assumption;high-strength stirrups which are set in high-strength concrete can effectively improve the problem in poor ductility of high-strength concrete ductility;the method with ignoring the contribution of longitudinal reinforcement to bearing capacity could be used to approximately offset the effect of the size effect in the design process.