Second-order inelastic analysis of shallow and non-shallow steel arches

Abstract This work presents a second-order inelastic analysis of steel arches. The analysis of shallow and non-shallow arches with several cross sections and boundary and loads conditions are discussed. The computational platform used is the homemade CS-ASA, which performs advanced nonlinear static and dynamic analysis of structures. The nonlinear geometric effects are considered using a co-rotational finite element formulation; the material inelasticity is simulated by coupling the Refined Plastic Hinge Method (RPHM) with the Strain Compatibility Method (SCM), and the static nonlinear solution is based on an incremental-iterative strategy including continuation techniques. In the simulated nonlinear steel arch models, special attention is given to the equilibrium paths, the influence of rise-to-span ratio, support and loading conditions and full yield curves among other factors. The numerical results obtained show good agreement with those from literature and highlight that the arch rise-to-span ratio has great influence on the structure resistance and that the shallow arches can lose stability through the snap-through phenomenon.摘要：本研究针对钢拱结构开展二阶非弹性分析。本文针对多种截面形式、边界条件与荷载工况下的浅拱与非浅拱，开展受力分析研究。本次分析采用自主研发的CS-ASA计算平台，该平台可实现结构的高级非线性静力与动力分析。分析中采用共旋转有限元列式（co-rotational finite element formulation）考虑几何非线性效应；材料非弹性行为通过将精化塑性铰法（Refined Plastic Hinge Method, RPHM）与应变协调法（Strain Compatibility Method, SCM）耦合进行模拟；静力非线性求解采用包含连续化技术的增量迭代策略。在模拟的非线性钢拱模型中，本文重点关注了平衡路径、矢跨比、支座与荷载工况以及全屈服曲线等诸多因素的影响。所得数值结果与已有文献成果吻合良好，同时表明拱的矢跨比对结构抗力具有显著影响，且浅拱可通过跳越失稳（snap-through）现象发生失稳。