A Method for Obtaining Vibration Frequency of Concrete Steel Tube Arch Bridge

Abstract

The invention relates to the technical field of arch bridge vibration frequency calculation, in particular to a steel tube concrete arch bridge vibration frequency calculating method which comprises the following steps: simulating components such as arch ribs, tie bar beams and transverse beams of a steel tube concrete arch bridge by using a beam unit, simulating a pull rope by using a rod unit, establishing a concrete beam unit rigidity matrix as shown in the specification when ambient temperature is introduced, establishing a steel tube beam unit rigidity matrix as shown in the specification when the ambient temperature is introduced, establishing a pull rope unit rigidity matrix as shown in the specification when the ambient temperature is introduced, establishing a steel tube concrete bridge structure overall rigidity matrix as shown in the specification when the ambient temperature is introduced, and solving a steel tube concrete bridge structure vibration characteristic value equation, thereby obtaining a structural characteristic value and a characteristic vector after temperature variation, wherein in the equations, the characteristic value lambda s is square of frequency; the characteristic vector {phi s} is a vibration mode. Frequency data obtained by using the steel tube concrete arch bridge vibration frequency calculating method provided by the invention can be used as prior data before an arch bridge is designed, the calculation result is visible, and reference can be provided for reasonable design, construction management and safe operation of the arch bridge.

Description

technical field The invention relates to the technical field of calculating the vibration frequency of an arch bridge, in particular to a method for obtaining the vibration frequency of a steel tube concrete arch bridge. Background technique Concrete-filled steel tube arch bridges have become the preferred type of long-span bridges due to their beautiful shape, light structure, superior mechanical performance, convenient construction, easy maintenance, strong spanning ability, and high stability, and have been widely used in my country. From the structural point of view, the CFST arch bridge is a complex high-order statically indeterminate structure, which has geometric nonlinearity and state nonlinearity, and the influence of environmental conditions makes the analysis of the dynamic characteristics of the CFST arch bridge more complicated. Yundi et al. analyzed the natural vibration characteristics and stability of a large-span medium-supported CFST arch bridge, and studi...

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Problems solved by technology

There are also some studies that consider the influence of wind speed and environmental excitation on the dynamic performance of arch bridges, but seldom consider the influence of temperature changes on the vibration of arch bridges.

In fact, due to the internal high-order hyperstatic property of the CFST arch bridge, the arch bridge is obviously affected by the change of ambient temperature. The vibration characteristics of the bridge are not only related to the inherent properties of the bridge, such as stiffness and mass, but also affected by the external temperature. If the influence of ambient temperature is not taken into account when calculating the vibration frequency of the arch bridge, the accuracy of the calculated vibration frequency of the arch bridge cannot be guaranteed, which is not conducive to practical engineering applications

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