Finite Element Analysis Of Plastic Hinge Length Of Rainforced Concrete Box Column

The plastic hinge theory is the basic theory of nonlinear analysis of structure,reinforced concrete structure in plastic hinges,the internal force and deformation are significantly affected.Based on this,many domestic and foreign scholars carried out a lot of research work on the properties of plastic hinges,and draw some reinforced concrete structure of the plastic hinge length calculation methods.But the current research on the plastic hinge length are based on the solid section,and the research about the box section is not many.Application prospect of reinforced concrete box structure because of its superior performance of stress has extensive application in high pier structure,so it is necessary to study the influence of reinforced concrete box structure the plastic hinge length factors.Through finite element analysis software ABAQUS to study the axial compression ratio,section size,shear span ratio,stirrup ratio,longitudinal reinforcement ratio of five factors on the plastic hinge length.And the influence of axial compression ratio,shear span ratio,volume stirrup ratio on the shear strength of plastic hinge region:(1)when the axial compression ratio is less than 0.3,increases with the increase of axial compression ratio of the reinforced concrete box column plastic hinge length;when the axial compression ratio more than0.3,the change trend of plastic hinge length is not obvious;the change of section size has great influence on the plastic hinge length decreases with the loading direction,the width of the cross section and the transverse thickness ratio increases,the longitudinal wall thickness ratio of the plastic hinge length is not obvious;increased with the increase of stirrup ratio of box column plastic hinge length;when the axial load level is lower,increasing the ratio of longitudinal reinforcement can significantly improve the length of plastic hinge the box column,if the axial pressure is large,longitudinal reinforcement ratio change effect on the plastic hinge length can be ignored.(2)The results of finite element analysis and Paulay formula,the European architectural engineering design specification,yuan Biguo formula is close to the calculation results of calculation formula in China for seismic design of highway bridge,the ratio of the simulation results and the calculation results were about 0.8,the plastic hinge length calculation of reinforced concrete box column using the formula,and has a certain safety margin.According to the results of finite element analysis using data analysis software,this paper summarizes the model of plastic hinge length calculation formula,and verified.(3)the box shear strength increases with the increase of axial compression ratio of column plastic hinge region;with shear span ratio increases,the shear strength of box column is greatly reduced;the shear strength increases with the increase of stirrup ratio model of plastic hinge region.