压弯圆弧拱平面外稳定承载力设计方法

Out-of-plane inelastic stability design of circular arches under combination of compression and bending

在均匀受压及受弯圆弧拱平面外稳定设计理论成果的基础上,采用大挠度弹塑性有限元分析方法,对压弯圆弧拱的平面外稳定承载力进行研究;考虑了钢拱几何参数、拱脚条件、截面形式、荷载组合等因素的影响,以有限元算例为依据,建立了压弯圆弧拱平面外稳定承载力的实用设计方法。研究表明:从圆弧拱的内力分布角度出发,通过引入轴力平均值、拱中段1/3弧长范围内最大弯矩以及考虑弯矩不均匀变化的受弯稳定系数等参数,建立基于稳定承载力N-M相关公式,在各种拱脚条件及复杂荷载组合工况下均具有较好的适用性。

Based on the previous studies on out-of-plane stability of arches in uniform compression and bending moment, this paper presented the research results of the out-of-plane ultimate strength of circular steel arches under the combination of axial compression and bending by using FE analysis in elasto-plastic range of materials. With the consideration of different geometric parameters, support conditions, section forms and load combinations etc, a design method for predicting the out-of-plane ultimate strength of circular steel arches was proposed based on FEA results. The results obtained indicate that the N-M interaction equation proposed for predicting the out-of-plane strength of arches is applicable for various support conditions and complex load combination, where average axial force, maximum bending moments within 1/3 arc length of arch top and stability coefficient for non-uniform moment distribution are introduced.