腹板开洞的工形截面拱的平面内特征值屈曲性能

用有限元模型分析了受径向均布荷载的腹板开洞的工形截面圆弧拱的平面内特征值屈曲性能。选用板壳单元构建了有限元模型,得出了较准确的特征值屈曲荷载和屈曲模态,获得了三种典型的特征值屈曲模态;通过选用一种代表开洞拱效率的特征值屈曲荷载参数,研究了腹板孔洞的半径和间距的优化尺寸。通过一系列拱的数值分析,给出了拱的矢跨比、长细比、孔洞的半径和间距对特征值屈曲荷载的影响,并把这些参数的影响归结为两个参数k和α,给出了这种腹板开洞拱的特征值屈曲荷载的简化计算公式。

IN-PLANE BUCKLING BEHAVIOR OF I-SECTIONAL ARCHES WITH WEB OPENINGS

A shell element model instead of beam element model is used to study the in-plane eigen buckling behavior of I-sectional arches with web openings subject to radially uniformly distributed load. More accurate eigen buckling loads and buckling modes of circular arches with web openings are obtained, including three typical eigen buckling modes. The optimization of the radius of openings and the gap between openings is performed based on a modified eigen buckling load, which corresponds to arch efficiency. Parameters such as the rise-to-span ratio, the slenderness ratio, the radius of openings and the gap between openings are investigated, and their effects on eigen buckling loads are discussed. Finally, a formula for calculating the eigen buckling load of I-sectional arches with web openings is proposed, in which two coefficients k and α reflect all parameters’ effects.