荷載橫向分布的彈性橫梁法
發(fā)布時間：2018-08-05 14:21
【摘要】：由于目前公路橋梁中出現(xiàn)了一些截面較高、跨徑較小的典型深梁橋,如果不考慮剪切變形的影響,撓度的計算結(jié)果就會偏小。本文考慮多梁式簡支斜梁的剪切變形的影響,推導集中豎向荷載、集中扭矩荷載作用下的撓度、扭角公式�？紤]縱梁的剪切變形及橫梁的柔性特征(抗彎剛度),視縱梁對橫梁的支承作用等效為彈性約束,在斜梁橋中考慮彎扭耦合效應,建立了利用傳遞矩陣法求解多梁式梁橋荷載橫向分布系數(shù)的彈性橫梁法,并與剛性橫梁法及有限單元法的計算結(jié)果進行比較,得到了如下結(jié)論：1、超靜定簡支斜梁跨度越小、截面越高,斜縱梁的剪切變形影響越大,特別是對斜縱梁兩端比對跨中的影響更明顯,而與荷載作用大小無關；2、在多梁式正梁橋中,取中橫梁進行有限元建模分析與傳遞矩陣法求解,兩者得到的結(jié)論基本一致；3、對使用傳遞矩陣法求解彈性橫梁的荷載橫向分布影響線(曲線)進行線性回歸,基本與使用剛性橫梁法計算的荷載橫向分布影響線(直線)吻合；4、彈性橫梁法與剛性橫梁法計算正(斜)梁橋跨中縱梁的荷載橫向分布系數(shù)比(次)邊縱梁要大,(次)邊縱梁相差較小,說明采用彈性橫梁法計算跨中縱梁荷載橫向分布系數(shù)的影響較大,而采用剛性橫梁法計算的結(jié)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.
【學位授予單位】：長沙理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U441.2
本文編號：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.
【學位授予單位】：長沙理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U441.2
【參考文獻】
相關期刊論文 前1條
1 張青;;廣義梁格法在曲線梁橋分析中的應用[J];交通標準化;2010年11期
，本文編號：2166058
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