摘要
利用Umansky闭口截面扭转理论,在现行GB 50017—2003"建筑钢结构规范"的基础上,得到适用于压-弯-扭共同作用下闭口截面构件弯矩作用平面内极限承载力的计算方法;采用数值分析方法对提出的设计公式进行验证,在建模时引入初始几何缺陷和残余应力,在分析时考虑几何非线性和物理非线性的影响;最后针对扭矩作用下矩形截面压弯构件截面塑性发展规律进行分析。研究结果表明:本文所提出计算公式能够真实反映构件的受力状态,使用便捷;在压力、弯矩和扭矩共同作用时可能存在的7种荷载路径对矩形截面钢管的极限承载力几乎没有影响;构件的抗弯和抗压极限承载力随着扭矩的增大而降低,且降低的程度越来越大;约束扭转的存在只会使截面最危险点更早地进入塑性状态,而对截面最终承载能力的影响不大,因此,根据自由扭转理论提出的设计公式对于存在约束扭转的矩形截面构件依然适用。
To obtain the in-plane ultimate strength of closed section members subjected to combined compression,bending and torsion,a new design method was proposed based on Umansky’s torsion theory and code for GB 50017-2003“Design of steel structures”.The ultimate strengths of in-plane buckling of closed section members subjected to combined compression,bending and torsion were analyzed by numerical analysis.The geometric initial imperfection and residual stress were taken into account when modeling and the nonlinearity of material and geometric were also taken into account.The results show that the proposed design method is suitable for the closed section members subjected to combined compression,bending and torsion.It reflects the real loading conditions and is also easy to be used.Seven kinds of load paths caused by combined compression,bending and torsion have little effect on the ultimate strength of models,and the design method has high accuracy.The bearing capacity of compression and bending decreases when torque increases,and this effect increases with the increase of torque.Restrained torsion causes the change of early plastic development while it has little influence on the ultimate strength of the rectangular box columns.Therefore,the design method based on free torsion theory is also suitable for the rectangular box columns under combined compression,bending and torsion.
作者
韩庆华
程禹皓
芦燕
HAN Qinghua;CHENG Yuhao;LU Yan(School of Civil Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Coast Civil Structure Safety of Ministry of Education,Tianjin University,Tianjin 300072,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第8期2039-2049,共11页
Journal of Central South University:Science and Technology
基金
国家重点研发计划项目(2016YFC0701103)
国家自然科学基金资助项目(51525803)
天津市建设系统科学技术发展计划项目(2014)~~
关键词
压-弯-扭共同作用
闭口截面
弯矩作用平面内极限承载力
约束扭转
荷载路径
combined compression
bending and torsion
closed section steel members
in-plane ultimate strength
restrained torsion
load path
