四肢格构式钢管混凝土压弯构件承载力计算OA

To derive the axial force-bending moment(N-M)correlation equations for the four-legged concrete-filled steel tubular(CFST)latticed members under combined compression and bending,this paper utilized the established finite element models to explore the stress states of four-legged CFST latticed standard members with various eccentricity ratios.The effects of main parameters on the N-M strength and stability relationship curves were analyzed,leading to the proposal of the mathematical models for these curves.The results indicate that there is a balanced point on the N-M interaction curves,which divides the curves into two parts:one controlled by the compressive yielding of chords in compressive zone and the other controlled by the tensile yielding of chords in tensile zone.As the sectional steel ratio and the yield strength of chord steel tube increase and the compressive strength of core concrete in chords decreases,the balanced point on the N-M interaction curve moves inward.Meanwhile,as the equivalent slenderness ratio of the member increases,the N-M interaction curve approaches a straight line.Moreover,compared to the bearing capacities calculated by existing formulas,the results predicted by the proposed N-M correlation equations show better agreement with the measured values.