Two-factor model of plastic development coefficient for circular concrete filled steel tube flexual member
In order to reflect the influence of the geometry and material property on the bending strength of circular concrete-filled steel tube(CFST)flexual members,the ratio of sectional thickness to diameter and the strength ratio of steel to concrete were chosen as two arguments,while the binary computational model of sectional plastic development coefficient(PDC),then the model of bending strength was proposed for circular CFST flexual members.Firstly,the numerical models of 1656 circular CFST flexual members were designed on the basis of determining the values of sectional thickness to diameter ratio and material strength ratio,the bending strengths and the PDCs of each member were evaluated by fiber model technique.Then,a binary computational model was developed for the sectional PDC of the circular CFST member under bending moments by means of regression analysis,adopting the ratio of sectional thickness to diameter and the strength ratio of steel to concrete as two arguments.Furthermore,the computational model was proposed for bending strength of the circular CFST member using the proposed PDC.Finally,the accuracy and applicability of the proposed models for the sectional PDC and the bending strength of the circular CFST flexual members were demonstrated by comparison with experimental data and existing models presented in current design specifications and literature.
circular concrete-filled steel tubeplasticity development coefficientbending strengthratio of sectional thickness to diameter