基于能量分析方法,推导了主拱肋和稳定拱肋拱轴线为悬链线的斜靠式拱肋系侧倾失稳临界荷载计算公式,并通过与有限元数值计算结果比较,证明了该计算公式的正确性,进一步验证了所提出的拱肋系侧倾失稳时横撑切向和径向力学模型的适用性,并将拱轴线为悬链线和圆弧曲线的斜靠式拱肋系的侧倾失稳临界荷载进行了比对分析,阐明了圆弧曲线代替悬链线斜靠式拱肋系侧倾失稳临界荷载的适用条件。研究结果表明:拱轴线的线型对斜靠式拱肋系的侧倾失稳临界荷载有一定的影响;当稳定拱肋倾角较小时,悬链线拱肋系的侧倾失稳临界荷载与圆弧曲线拱肋系的差异不超过5%;当矢跨比较小时,圆弧曲线拱肋系代替悬链线拱肋系的侧倾失稳临界荷载产生的误差在10%以下,但矢跨比较大时,二者的差异较大,不可等同。
Based on energy analysis method, the calculation formula of lateral buckling critical load of the leaning-type arch ribs with the catenary arch axis is derived. Compared with the results obtained from FEM, the analytical solution formula presented is verified in this paper. The applicability of the lateral and radial mechanical models of transverse brace between the main arch rib and stable arch rib proposed are validated. Furthermore, the lateral buckling critical load under circular arch axis and catenary are compared, while the quantity relationship and the applicable condition that replacing the lateral buckling critical load of catenary arch with the circular arch are analyzed. It is shown that the line-type of arch axis has a certain extent impact on the lateral buckling critical load of the leaning-type arch ribs. When the incline angle of stable ribs is small, the difference of the lateral buckling critical load between the catenary arch rib system and circular arch rib system is less than 5%. The error induced by the lateral buckling critical load of circular arch rib system replacing that of the catenary arch rib system will be less than 10% when the rise-span ratios are small enough. With the increasing of rise-span ratios, the differences will increase and the replacement is not feasible.