摘要
采用ANSYS软件,建立张弦梁结构热力耦合数值分析模型,讨论结构温度分布等一些因素对张弦梁结构受火失效模式及临界温度的影响,得到如下结论:张弦梁结构的失效模式按临界荷载比可分为上弦钢梁破坏和下弦钢索破坏.当结构为下弦钢索破坏时,随着荷载比增加或支座摩阻力的减小,结构临界温度降低,预应力比、矢跨比、垂跨比、上弦钢梁刚度及温度分布系数对结构的临界温度影响较小,火源位置及火源半径对结构临界温度无影响.当为上弦钢梁破坏时,其临界温度随荷载比、预应力比、矢跨比、垂跨比及支座摩阻力的增加或随温度分布系数、上弦钢梁刚度的减小而降低.火源位于位置A为最不利火灾位置,火源半径对临界温度无影响.在上述参数分析的基础上,提出两端铰支座的张弦梁临界温度计算式,可为张弦梁结构抗火承载力提供验算依据.
A numerical analysis model of thermodynamic coupling of the beam string structure was established with ANSYS software,and the influence of some factors such as structural temperature distribution on failure mode and critical temperature of the beam was discussed,so that following conclusion was obtained:the failure model of this beam structure can be divided into the destruction of up-chordal steel beam and the destruction of down-chordal steel cable according to critical load ratio;when the down-chordal pre-tensioned cable is failed,with the increase of load ratio or the decrease of frictional resistance of supporter,the critical temperature of structure will decrease and the pre-stress ratio,rise-to-span ratio,sag-to-span ratio,stiffness of up-chordal steel beam,and its temperature distribution coefficient will have less effect on the structural critical temperature.The influence of other parameters can be ignored;when the up-chordal steel beam failed,the critical temperature of structure will be decreased with the decrease of temperature distribution coefficient and stiffness of up-chordal beam or with increase of load ratio,rise-to-span ratio,pre-stress ratio,sag-to-span ratio,and frictional resistance of supporter.The location of fire origin A will be the most disadvantageous position,and the influence of other parameters can be ignored.On the basis of above-mentioned parameter analysis,a computation formula is presented for the critical temperature of the stringed beam will hinge joints at both ends,that can provide a checking basis for anti-fire bearing capacity of the beam string structure.
作者
王彬彬
杜咏
张浩
WANG Bin-bin;DU Yong;ZHANG Hao(College of Civil Engineering,Nanjing Tech University,Nanjing 211800,China)
出处
《兰州理工大学学报》
CAS
北大核心
2018年第5期137-143,共7页
Journal of Lanzhou University of Technology
基金
国家自然科学基金(51378259)
土木工程防灾国家重点实验室开放基金项目(SLDRCE 14-05)
江苏省其他厅局科技计划项目(ZX15512350001)
关键词
张弦梁结构
参数分析
破坏模式
临界温度
beam string structure
parameter analysis
failure mode
critical temperature
作者简介
王彬彬(1993-),男,河南周口人,硕士.;通讯作者:杜咏(1967-),女,重庆人,博士,教授.
