摘要
目前我国的桥梁工程中,大多数仍为简支梁桥。在横向荷载作用下,简支梁桥主要以受弯为主。蜂窝梁作为较早被人们使用的一种钢结构主梁,具有抗弯能力强的特点,但在以受弯为主的简支梁桥中却鲜有使用,这主要是由于蜂窝梁腹板高度较大,在车辆荷载等动荷载作用下极易出现腹板屈曲畸变。为尝试将蜂窝梁应用于桥梁工程领域,基于蜂窝梁外观,提出了一种新型钢结构主梁——正八边形钢板腹梁。对该结构的腹板应力计算方法和纯剪切屈曲计算系数进行研究,以期对该结构的实际应用提供借鉴。为研究该结构的腹板应力计算方法,基于费式空腹桁架比拟法进行相关计算的假设,并将该结构的腹板划分为5个计算区域,提出腹板应力计算方法并得到相应的计算公式,通过与试验结果对比的方式,对腹板应力计算方法的合理性进行验证。为研究腹板的纯剪切屈曲系数,基于纯剪切矩形薄板屈曲计算理论,采用通用有限元软件ABAQUS计算得到不同设计参数和不同边界条件的480个圆形开孔八边形薄板的屈曲系数,通过对不同边界条件的纯剪切矩形薄板屈曲系数计算公式进行修正,从而得到正八边形开孔腹板在纯剪应力作用下的屈曲系数。结果表明:在横向荷载作用下,该结构的底板和顶板主要受轴力作用,剪力作用可忽略,而腹板主要受剪力作用,轴力作用可忽略。通过对试验梁进行静载弯曲试验,得到了该结构的弯曲破坏形态,试件在加载点位置处出现腹板屈曲现象。将腹板开孔边缘应变实测值换算为应力实际值,并与腹板应力计算值进行对比。可以发现,所提出腹板应力计算方法可以较好地预测圆孔环向应力的分布模式,环向应力分布近似均匀。在计算截面θ=π/2处,腹板环向应力的计算值与实测值相差较大,这是由于在简化计算中假定圆孔中心为反弯点导致的计算误差。基于有限元软件ABAQUS和数据拟合提出的八边形圆形开孔薄板的屈曲系数,可为该结构的相关设计提供参考。
At present,most of the bridge projects in China are still simply supported beam bridges.Under the action of transverse load,the simply supported beam bridge is mainly flexural.As a kind of steel structure girder used earlier,honeycomb beam has the characteristics of strong bending resistance,but it is rarely used in simply supported beam bridge.This is mainly due to the large web height of honeycomb beam,which is prone to web buckling distortion under dynamic loads such as vehicle loads.In order to apply the honeycomb beam to the field of bridge engineering,based on the appearance of honeycomb beam,a new type of steel structure main beam-steel octagon-web beam was proposed.The web stress calculation method and pure shear buckling calculation coefficient of the structure were studied in order to provide reference for the practical application of the structure.Based on the assumption of the Vierendeel truss theory,the web of the structure is divided into five calculation areas,the web stress calculation method is proposed and the corresponding calculation formula is obtained,and the rationality of the web stress calculation method is verified by comparing with the test results.In order to study the pure shear buckling coefficient of the web,based on the pure shear rectangular thin plate buckling calculation theory,the general finite element software ABAQUS is used to calculate the buckling coefficient for 480 octagonal thin plate with different design parameters and different boundary conditions.By modifying the calculation formula of the pure shear rectangular thin plate buckling coefficient with different boundary conditions,the buckling coefficient of the regular octagonal perforated web under the pure shear stress is obtained.The results show that under the transverse load,the bottom slab and top slab of the structure are mainly subject to axial force,and the shear force effect can be ignored,while the web is mainly subject to shear force,and the axial force effect can be ignored.Through the static load bending test of the specimen,the bending failure mode of the structure is obtained,and the web buckling phenomenon occurs at the loading point of the test piece.The measured values of the strain at the edge of the web opening are converted into the actual values of the stress,and compared with the calculated values of the web stress.It can be found that the proposed web stress calculation method can better predict the distribution mode of circumferential stress of circular holes,and the circumferential stress distribution is approximately uniform.In the calculating section θ=π/2,there is a large difference between the theoretical calculation and the measured values due to the calculation error caused by the assumption that the center of the circular hole is the inflection point in the simplified calculation.Based on the finite element software ABAQUS and data fitting,the buckling coefficient of octagonal circular perforated plate is proposed,which can provide a reference for the relevant design of the structure.
作者
常山
杨明
田林杰
徐继昌
Shan Chang;Ming Yang;Linjie Tian;Jichang Xu(Architecture College,Anhui Science and Technology University,Bengbu 233030,China;School of Transportation,Southeast University,Nanjing 211189,China)
出处
《钢结构（中英文）》
2023年第1期13-20,共8页
Steel Construction（Chinese & English）
基金
国家自然科学基金青年项目(51208102)
江苏省“六大人才高峰”第十二批(JY-003)
安徽科技学院人才引进项目(JZYJ202102)
2022年安徽省国家级大学生创新创业训练计划项目(202210879009)
