薄壁杆件组合扭转中约束扭转占比研究  

Research on proportion of constrained torsion in mixed torsion of thin-walled bar

作　　者：刘永健[1,2] 柴亮 邢子寒 李江江 封博文 LIU Yong-jian;CHAI Liang;XING Zi-han;LI Jiang-jiang;FENG Bo-wen(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;Research Center of Highway Large Structure Engineering on Safety of Ministry of Education,Chang'an University,Xi'an 710064,Shaanxi,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]长安大学公路大型结构安全教育部工程研究中心,陕西西安710064

出　　处：《长安大学学报（自然科学版）》2024年第2期46-56,共11页Journal of Chang’an University(Natural Science Edition)

基　　金：中央高校基本科研业务费专项资金项目(300102219310);宁波市交通运输科技项目(202301)。

摘　　要：为确定在不同边界条件下薄壁杆件以组合扭转方式抗扭时自由扭转和约束扭转的比例关系,首先,基于Vlasov薄壁结构理论建立组合扭转微分方程,并按照初参数法推导出薄壁杆件在集中扭矩和均布扭矩作用下的约束扭转占比公式。以简支边界为基准,通过引入约束刚度系数β,分析边界条件对于约束扭转占比的影响。然后,使用有限元软件ABAQUS对公式进行验证。最后,给出钢结构桥梁常见截面的约束扭转特征系数κ的计算公式,并统计双工字钢板组合梁桥与钢箱梁桥的κ分布范围。研究结果表明:所推导的约束扭转占比公式与ABAQUS计算结果吻合良好;约束扭转占比与截面的κ和边界条件有关;κ越大,约束扭转占比越小,且随着κ变化,边界条件对于约束扭转占比的影响程度发生变化;β可以表征边界条件对约束扭转占比的影响程度;简化分析时,当0<κ≤0.6时可以忽略自由扭转的影响,仅按约束扭转进行分析,当κ≥40时可以忽略约束扭转的影响,仅按自由扭转进行分析,当0.6<κ<40时需按组合扭转进行分析;所统计的双工字钢板组合梁桥的κ为0.71~1.58,钢箱梁桥的κ>39。In order to determine the proportional relationship between pure torsion and constrained torsion of thin-walled bar under mixed torsion with different boundary conditions,firstly,the mixed torsion differential equation was established based on Vlasov thin-walled structure theory.The proportion formula for constrained torsion of thin-walled bar under concentrated torque and uniform torque was derived using the initial parameter method.Based on simply supported boundary,the influence of boundary conditions on the proportion of constrained torsion was analyzed by introducing the constraint stiffness coefficientβ.Then,the formula was verified using the finite element software ABAQUS.Finally,the calculation formula for the constrained torsion characteristic coefficientκof the common section of steel bridge was provided,and the distribution range ofκfor the steel-concrete composite twin I-girder bridge and the steel box girder bridge were counted.The results show that the derived formula for constrained torsion ratio agrees well with the calculation results obtained from ABAQUS.The proportion of constrained torsion is affected by the section'sκand boundary conditions.A largerκcorresponds to a smaller proportion of constraint torsion,and the influence of boundary conditions on the proportion of constraint torsion changes withκ.Theβcan effectively characterize the influence of boundary conditions on the proportion of constraint torsion.In simplified analysis,when 0<κ≤0.6,the influence of pure torsion can be disregarded,and the analysis can focus solely on constrained torsion.Whenκexceeds 40,the impact of constrained torsion can be neglected,and the analysis can be based solely on pure torsion.In the case where 0.6<κ<40,a mixed torsion analysis is required.The calculatedκrange for the steel-concrete composite twin I-girder bridge is 0.71 to 1.58,and theκfor the steel box beam bridge is greater than 39.

关 键 词：桥梁工程 薄壁杆件 有限元模型 自由扭转 约束扭转 边界条件 

分 类 号：U441[建筑科学—桥梁与隧道工程]