变截面波形钢腹板组合箱梁剪力滞效应的比拟杆法求解  

Bar Simulation Method for Shear Lag Analysis of Non-prismatic Composite Box Girders with Corrugated Steel Webs

作　　者：周聪 汪建群[1,2] 李立峰[3] ZHOU Cong;WANG Jianqun;LI Lifeng(Hunan Provincial Key Laboratory of Structures for Wind Resistance and Vibration Control,Hunan University of Science and Technology,Xiangtan 411201,China;School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南科技大学结构抗风与振动控制湖南省重点实验室,湖南湘潭411201 [2]湖南科技大学土木工程学院,湖南湘潭411201 [3]湖南大学土木工程学院,湖南长沙410082

出　　处：《铁道学报》2022年第4期143-152,共10页Journal of the China Railway Society

基　　金：国家自然科学基金(52108140);湖南省自然科学基金(2020JJ4310,2021JJ40213);湖南省教育厅基金(21B0497)。

摘　　要：为研究变截面波形钢腹板组合箱梁的剪力滞效应,充分考虑该组合箱梁的结构和受力特点,推导加劲杆等效面积和波形钢腹板剪力流的计算公式,建立剪力滞控制微分方程,并基于给定的边界条件对微分方程进行求解,由此建立用于分析变截面波形钢腹板组合箱梁剪力滞效应的修正比拟杆法。选取两根变截面梁作为数值算例,包括单箱单室悬臂梁和单箱三室悬臂梁,对提出的理论方法进行验证,理论解与数值解吻合良好,表明该理论方法可准确分析变截面波形钢腹板组合箱梁的剪力滞效应,且适用于单箱单室和单箱多室截面形式。在此基础上,分析加劲杆个数对修正比拟杆法计算精度的影响,并探讨宽跨比、梁高比和荷载形式等因素对变截面波形钢腹板悬臂箱梁剪力滞效应的影响规律。结果表明:修正比拟杆法的计算精度对加劲杆个数不敏感,但加劲杆个数越多能更好地反映正应力沿横向的分布规律,建议将混凝土顶、底板分别等效为9根和5根加劲杆;随着宽跨比和梁高比的增加,剪力滞效应会更为突出;荷载形式对剪力滞效应有显著影响,并会改变正、负剪力滞区段分割点的位置。To investigate the shear lag effect of non-prismatic composite box girders with corrugated steel webs(CBGCSWs),formulas for the equivalent area of stiffening bar and the shear flow in corrugated steel webs were derived by properly considering the structural and mechanical properties of non-prismatic CBGCSWs.Then,the governing differential equations for shear lag were formulated and solved with the given boundary conditions.Finally,the modified bar simulation method for shear lag analysis of non-prismatic CBGCSWs was established.Two non-prismatic beams,including single-box single-cell cantilever beam and single-box triple-cell cantilever beam,were chosen as numerical examples to validate the proposed theoretical method.The well-agreed theoretical and numerical results demonstrated that the proposed theoretical method can accurately analyze the shear lag effect of non-prismatic CBGCSWs,and was applicable to non-prismatic beams with single-box single-cell and single-box multi-cell sections.On this basis,the effect of the number of stiffening bars on the calculation accuracy of the modified bar simulation method was analyzed,followed by a discussion on the effects of width-span ratio,girder height ratio and load form on the shear lag effect of non-prismatic cantilever CBGCSWs.The results indicate that the modified bar simulation method is insensitive to the number of stiffening bars,but dispersing the concrete slab into more stiffening bars could better reflect the normal stress distribution of concrete flange along the girder width direction.The top and bottom concrete slabs are suggested to be dispersed into 9 and 5 stiffening bars,respectively.The shear lag effect will be more serious with the increase of width-span ratio or girder height ratio.The load form can significantly impact the shear lag behavior,and can change the dividing points between the negative and positive shear lag sections.

关 键 词：波形钢腹板组合箱梁 剪力滞效应 变截面 比拟杆法 有限元分析 参数分析 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]