抛物线形钢管混凝土无铰拱出平面稳定性能研究

Out-of-plane buckling behavior of slender parabolic concrete-filled steel tubular arches with fixed ends

利用有限元软件ABAQUS建立了沿跨度方向均布荷载作用下的圆形截面抛物线形钢管混凝土无铰拱有限元模型,在验证了有限元模型可靠性的基础上,通过参数分析研究了含钢率、钢材强度、混凝土强度、矢跨比以及几何长细比对其出平面稳定承载力的影响;基于参数分析结果,结合钢管混凝土统一理论,对抛物线形无铰拱在沿跨度方向均布荷载作用下的出平面稳定承载力经典公式进行修正,提出了相应的抛物线形钢管混凝土无铰拱出平面稳定承载力设计式。结果表明:含钢率、钢材强度、混凝土强度、矢跨比以及几何长细比对拱肋出平面稳定承载力的影响均不容忽视;在所分析参数范围内,设计式与有限元分析结果的相关系数达0.973,两者吻合良好。

The finite element model of parabolic concrete-filled steel tubular arches with both ends fixed was developed to investigate its out-of-plane buckling behavior when subjected to uniformly-distributed vertical load using ABAQUS software. The reliability of the model was verified. A parametric analysis was then carried out to study the influences of ratio of steel area to concrete area,steel strength,concrete strength,slenderness ratio and rise-to-span ratio on the ultimate resistance of the arches. Based on the finite element analysis results,a design formula was proposed by modifying the classic out-of-plane buckling equation for uniformly loaded parabolic arches with fixed ends and uniform material using unified theory for CFST. In conclusion,the ultimate resistance of the arches depends on the ratio of steel area to concrete area,steel strength,concrete strength,rise-to-span ratio and slenderness ratio. The proposed design formula is in good agreement with the finite element model analysis with the correlation coefficient of 0. 973.