斜靠式拱肋系侧倾失稳临界荷载计算方法

CALCULATION METHOD FOR LATERAL BUCKLING CRITICAL LOAD OF LEANING-TYPE ARCH RIB SYSTEM

该文以近年来发展起来的一种新型空间拱桥——斜靠式拱桥拱肋系为研究对象,基于最小势能原理,综合考虑斜靠式拱肋系主拱肋、稳定拱肋、主拱肋与稳定拱肋间横撑的变形能、作用于拱肋系的外力势能,首次推导出了斜靠式拱肋系侧倾失稳临界荷载的解析解,提出了斜靠式拱肋系侧倾失稳临界荷载的计算方法,并通过与有限元计算结果比较,证明了该文所提出计算方法的正确性。在此基础上研究了稳定拱肋倾角变化、及其侧向抗弯和抗扭刚度,主拱肋与稳定拱肋间横撑抗弯刚度对临界荷载的影响,研究结果表明稳定拱肋倾角和侧向抗弯刚度是控制斜靠式拱桥侧向稳定性的主要因素。

This paper focuses on the arch rib system of a leaning-type arch bridge which is a new type space arch bridge developed in recent years,the following investigation is carried out： Based on the principle of minimum potential,as well as the deformation energy of main ribs,stable ribs,the transverse brace between the main rib and stable rib,and the potential energy of an external force applied on the ribs system,the lateral buckling critical load of a leaning-type arch rib system is derived in this paper,by which the calculation method for the lateral buckling critical load is proposed.Compared with the results obtained from FEM results,it is verified that the method presented in this paper is accurate sufficiently.Furthermore,it is analyzed how those design parameters such as variation of incline angles,the lateral flexural rigidity and torsional rigidity of a stable rib and a transverse brace between the main rib,the stable rib influence on the lateral buckling critical load.The investigation shows that the incline angle and lateral flexural rigidity of stable rib are main factors to ensure the lateral buckling of a leaning-type arch rib system.