摘要
以均布荷载下的抛物线钢管拱为研究对象,在考虑双重非线性的有限元分析基础上,讨论了完善拱和有初始几何缺陷的拱的弹性失稳和弹塑性失稳的特性,提出纯压钢管拱稳定临界荷载计算的等效柱法。分析结果表明,矢跨比是计算拱临界荷载的重要影响因素,而现有等效柱法中没有考虑这一因素的影响,为此,提出等效柱的稳定系数中考虑矢跨比影响的计算方法。有初始几何缺陷的拱将发生极值点失稳,且极值点荷载要小于分支屈曲临界荷载,为此提出缺陷拱等效柱法考虑缺陷影响的计算方法。给出了钢管拱失稳临界荷载等效柱法计算的相应公式和实用表格。与双重非线性有限元计算结果对比表明,提出的等效柱法能方便且较精确地估算钢管拱的非线性临界荷载。
Focusing on parabolic steel tubular arch with and without initial crookedness subjected to distributed load,the characteristics of elastic and elastic-plastic buckling are discussed based on the finite element analysis considering dual-nonlinearity.Analysis results show that,rise-to-span ratio is an important factor in critical loading of an arch,but which does not appear in the present equivalent column method,thus a method considering influence of rise-to-span factor is presented.An arch with initial defect buckles under critical load smaller than the buckling load for a perfect arch,so a coefficient considering the lower critical loading due to initial defect is introduced into the equivalent column method.A comparison with the results from dual nonlinearity finite element method indicates the accuracy of method for estimating nonlinear critical loading of steel tubular arch.
出处
《应用力学学报》
CAS
CSCD
北大核心
2009年第1期194-200,共7页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金(50778043)
福建省科技厅项目(JA07014)
关键词
钢管拱
稳定
等效柱法
矢跨比
初始几何缺陷
双重非线性
有限元
steel tubular arch,stability,equivalent column method,rise-to-span ratio,initial crookedness,dual-nonlinearity
