Deflection is the most direct indicator that reflects the bearing capacity of the bridge and the overall stiffness. There are many ways to measure the deflection of Bridges, and the inclination angle method is the mos...Deflection is the most direct indicator that reflects the bearing capacity of the bridge and the overall stiffness. There are many ways to measure the deflection of Bridges, and the inclination angle method is the most commonly used indirect method, but the existing theory of inclination angle method is relatively complicated. Based on the facts of the bridge small inclination, this article proposes the method of obtaining the bridge deflection by the inclination of the secant line constructed from the adjacent measurement points. Firstly, according to the bending deformation curve of general simply supported beam, the deflection calculation formula of each measuring point is derived based on the assumption of small deformation and the inclination Angle of measuring point. Secondly, a large commercial finite element software ANSYS 10.0 is used to carry out numerical simulation on the simply-supported beam under concentrated load in mid-span, and the deflection results of the numerical simulation are compared and verified with the theoretical results of the proposed method. Finally, the measured deflection results of the simply-supported beam model under mid-span load are compared with the theoretical results of the proposed method. The verification results show that if the actual model is consistent with the theoretical model, the proposed method has good accuracy.展开更多
This paper analyze the effects of loads changing position on the soil-steel structures made of corrugated plates. The analyzed quantity is the shell deflection depending on the location of vehicles, On this basis, the...This paper analyze the effects of loads changing position on the soil-steel structures made of corrugated plates. The analyzed quantity is the shell deflection depending on the location of vehicles, On this basis, the influence functions of deflection are determined. On the basis of results of tests conducted on numerous soil-steel structures, it has been proved that the deflection influence line, which is commonly used in the static analysis of bridges, can not be obtained for this type of structures. This is due to the form of deflection and deflection differences that occur during a primary passage and a secondary （return） passage of the moving load. The deflection influence functions analyzed in the paper are used to determine the stiffness of classic beam bridges, masonry bridges and soil-steel structures. This allows to conduct comparative analyses of different groups of bridges （road bridges, railway bridges, pedestrian bridges）, using results of the tests performed under the service load.展开更多
A novel model is proposed which comprises of a beam bridge subjected to an axial load and an infinite series of moving loads. The moving loads, whose distance between the neighbouring ones is the length of the beam br...A novel model is proposed which comprises of a beam bridge subjected to an axial load and an infinite series of moving loads. The moving loads, whose distance between the neighbouring ones is the length of the beam bridge, coupled with the axial force can lead the vibration of the beam bridge to codimension-two bifurcation. Of particular concern is a parameter regime where non-persistence set regions undergo a transition to persistence regions. The boundary of each stripe represents a bifurcation which can drive the system off a kind of dynamics and jump to another one, causing damage due to the resulting amplitude jumps. The Galerkin method, averaging method, invertible linear transformation, and near identity nonlinear transformations are used to obtain the universal unfolding for the codimension-two bifurcation of the mid-span deflection. The efficiency of the theoretical analysis obtained in this paper is verified via numerical simulations.展开更多
文摘Deflection is the most direct indicator that reflects the bearing capacity of the bridge and the overall stiffness. There are many ways to measure the deflection of Bridges, and the inclination angle method is the most commonly used indirect method, but the existing theory of inclination angle method is relatively complicated. Based on the facts of the bridge small inclination, this article proposes the method of obtaining the bridge deflection by the inclination of the secant line constructed from the adjacent measurement points. Firstly, according to the bending deformation curve of general simply supported beam, the deflection calculation formula of each measuring point is derived based on the assumption of small deformation and the inclination Angle of measuring point. Secondly, a large commercial finite element software ANSYS 10.0 is used to carry out numerical simulation on the simply-supported beam under concentrated load in mid-span, and the deflection results of the numerical simulation are compared and verified with the theoretical results of the proposed method. Finally, the measured deflection results of the simply-supported beam model under mid-span load are compared with the theoretical results of the proposed method. The verification results show that if the actual model is consistent with the theoretical model, the proposed method has good accuracy.
文摘This paper analyze the effects of loads changing position on the soil-steel structures made of corrugated plates. The analyzed quantity is the shell deflection depending on the location of vehicles, On this basis, the influence functions of deflection are determined. On the basis of results of tests conducted on numerous soil-steel structures, it has been proved that the deflection influence line, which is commonly used in the static analysis of bridges, can not be obtained for this type of structures. This is due to the form of deflection and deflection differences that occur during a primary passage and a secondary （return） passage of the moving load. The deflection influence functions analyzed in the paper are used to determine the stiffness of classic beam bridges, masonry bridges and soil-steel structures. This allows to conduct comparative analyses of different groups of bridges （road bridges, railway bridges, pedestrian bridges）, using results of the tests performed under the service load.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11002093,11172183,and 11202142)the Science and Technology Fund of the Science and Technology Department of Hebei Province,China(Grant No.11215643)
文摘A novel model is proposed which comprises of a beam bridge subjected to an axial load and an infinite series of moving loads. The moving loads, whose distance between the neighbouring ones is the length of the beam bridge, coupled with the axial force can lead the vibration of the beam bridge to codimension-two bifurcation. Of particular concern is a parameter regime where non-persistence set regions undergo a transition to persistence regions. The boundary of each stripe represents a bifurcation which can drive the system off a kind of dynamics and jump to another one, causing damage due to the resulting amplitude jumps. The Galerkin method, averaging method, invertible linear transformation, and near identity nonlinear transformations are used to obtain the universal unfolding for the codimension-two bifurcation of the mid-span deflection. The efficiency of the theoretical analysis obtained in this paper is verified via numerical simulations.
