荷载横向分布的弹性横梁法
发布时间：2018-08-05 14:21
【摘要】：由于目前公路桥梁中出现了一些截面较高、跨径较小的典型深梁桥,如果不考虑剪切变形的影响,挠度的计算结果就会偏小。本文考虑多梁式简支斜梁的剪切变形的影响,推导集中竖向荷载、集中扭矩荷载作用下的挠度、扭角公式。考虑纵梁的剪切变形及横梁的柔性特征(抗弯刚度),视纵梁对横梁的支承作用等效为弹性约束,在斜梁桥中考虑弯扭耦合效应,建立了利用传递矩阵法求解多梁式梁桥荷载横向分布系数的弹性横梁法,并与刚性横梁法及有限单元法的计算结果进行比较,得到了如下结论：1、超静定简支斜梁跨度越小、截面越高,斜纵梁的剪切变形影响越大,特别是对斜纵梁两端比对跨中的影响更明显,而与荷载作用大小无关；2、在多梁式正梁桥中,取中横梁进行有限元建模分析与传递矩阵法求解,两者得到的结论基本一致；3、对使用传递矩阵法求解弹性横梁的荷载横向分布影响线(曲线)进行线性回归,基本与使用刚性横梁法计算的荷载横向分布影响线(直线)吻合；4、弹性横梁法与刚性横梁法计算正(斜)梁桥跨中纵梁的荷载横向分布系数比(次)边纵梁要大,(次)边纵梁相差较小,说明采用弹性横梁法计算跨中纵梁荷载横向分布系数的影响较大,而采用刚性横梁法计算的结果偏小。
[Abstract]:Because there are some typical deep beam bridges with high cross section and small span in highway bridges, if the effect of shear deformation is not considered, the calculation results of deflection will be smaller. In this paper, the effects of shear deformation on multi-beam simply supported oblique beam are considered, and the formulas of deflection and torsion angle under concentrated vertical load and concentrated torque load are derived. Considering the shear deformation of the longitudinal beam and the flexible characteristic of the beam (flexural stiffness), the supporting effect of the longitudinal beam on the beam is equivalent to the elastic constraint, and the coupling effect of bending and torsion is considered in the skew beam bridge. An elastic beam method using transfer matrix method to solve the transverse load distribution coefficient of multi-beam bridge is established, and compared with the calculation results of rigid beam method and finite element method, the following conclusions are obtained: 1, the smaller the span of simply supported oblique beam is, the smaller the span of simply supported skew beam is. The higher the cross section, the greater the influence of shear deformation of inclined longitudinal beam, especially on the two ends of oblique longitudinal beam than in the middle of span, but independent of the magnitude of load, in multi-beam forward beam bridge, The finite element modeling analysis and the transfer matrix method are used to analyze the middle beam. The conclusion is basically consistent with that obtained by the transfer matrix method. The linear regression is carried out to solve the influence line (curve) of the transverse load distribution of the elastic crossbeam by using the transfer matrix method. It basically coincides with the influence line (straight line) of load distribution calculated by rigid beam method. 4. The transverse load distribution coefficient of the middle span longitudinal beam of a positive (oblique) beam bridge is larger than that of the (secondary) side longitudinal beam, and the difference between the (secondary) side longitudinal beam and the (secondary) side longitudinal beam is relatively small, by using the elastic beam method and the rigid beam method. It is shown that the calculation of transverse load distribution coefficient of mid-span longitudinal beam by elastic beam method is more important than that by rigid beam method.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.2
本文编号：2166058
[Abstract]:Because there are some typical deep beam bridges with high cross section and small span in highway bridges, if the effect of shear deformation is not considered, the calculation results of deflection will be smaller. In this paper, the effects of shear deformation on multi-beam simply supported oblique beam are considered, and the formulas of deflection and torsion angle under concentrated vertical load and concentrated torque load are derived. Considering the shear deformation of the longitudinal beam and the flexible characteristic of the beam (flexural stiffness), the supporting effect of the longitudinal beam on the beam is equivalent to the elastic constraint, and the coupling effect of bending and torsion is considered in the skew beam bridge. An elastic beam method using transfer matrix method to solve the transverse load distribution coefficient of multi-beam bridge is established, and compared with the calculation results of rigid beam method and finite element method, the following conclusions are obtained: 1, the smaller the span of simply supported oblique beam is, the smaller the span of simply supported skew beam is. The higher the cross section, the greater the influence of shear deformation of inclined longitudinal beam, especially on the two ends of oblique longitudinal beam than in the middle of span, but independent of the magnitude of load, in multi-beam forward beam bridge, The finite element modeling analysis and the transfer matrix method are used to analyze the middle beam. The conclusion is basically consistent with that obtained by the transfer matrix method. The linear regression is carried out to solve the influence line (curve) of the transverse load distribution of the elastic crossbeam by using the transfer matrix method. It basically coincides with the influence line (straight line) of load distribution calculated by rigid beam method. 4. The transverse load distribution coefficient of the middle span longitudinal beam of a positive (oblique) beam bridge is larger than that of the (secondary) side longitudinal beam, and the difference between the (secondary) side longitudinal beam and the (secondary) side longitudinal beam is relatively small, by using the elastic beam method and the rigid beam method. It is shown that the calculation of transverse load distribution coefficient of mid-span longitudinal beam by elastic beam method is more important than that by rigid beam method.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.2
【参考文献】
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1 张青;;广义梁格法在曲线梁桥分析中的应用[J];交通标准化;2010年11期
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