Steel bridge fatigue evaluation load modeling and fatigue evaluating method

Abstract

The invention discloses a steel bridge fatigue evaluation load modeling and fatigue evaluating method. The steel bridge fatigue evaluation load modeling and fatigue evaluating method comprises, step one, establishing a train load model; step two, processing and classifying measured data; step three, according to the measured data, establishing a probability model for parameters; step four, establishing a train load probability model; step five, generating a random load spectrum through a Monte-Carlo method; step six, through finite element analysis, acquiring stress influence lines of steel bridge fatigue details; step seven, performing influence line loading through the random load spectrum to obtain a stress history; step eight, analyzing the stress history to evaluate steel bridge fatigue. The steel bridge fatigue evaluation load modeling and fatigue evaluating method has the advantages of, through the fatigue evaluation load model which is established on the basis of the measured data for describing the load status of currently-running trains, achieving fatigue evaluation of any component of a steel bridge, establishing a complete train load modeling method, improving the utilization value of the measured data and ensuring more accurate and more practical steel bridge fatigue evaluation.

Description

Technical field [0001] The invention relates to the technical field of railway bridges, and in particular to a fatigue evaluation load modeling and fatigue evaluation method for steel bridges. Background technique [0002] With the increase of railway operation time, how to evaluate the railway structure, the main aspect is to determine the evaluation load. Especially for railway steel bridges, when performing fatigue assessment, the fatigue failure characteristics are not only related to the magnitude of the stress change under load, but also related to the number of stress changes. Therefore, when the steel bridge is designed, the relevant specifications are usually adopted The specified fatigue load spectrum is checked to control the fatigue stress. [0003] In the existing steel bridge fatigue assessment load model, the fatigue damage of steel components is generally calculated based on the actual measured data on the spot or calculated through typical train load calculations,...

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Problems solved by technology

[0003] In the existing steel bridge fatigue evaluation load model, the detection and calculation of the fatigue damage degree of steel members is generally calculated based on the actual measured data on the spot or calculated by the typical train load, but there is a certain difference from the actual situation, and with the operating train load and As the number increases, the loads on bridges become more and more complex, and the existing typical train load models are difficult to reflect the actual situation

In addition, fatigue load generally includes measured load spectrum, standard load spectrum and fatigue load model. In order to obtain more accurate evaluation results, measured data is often used for analysis. However, due to the large amount of measured data and complex applications, it is generally simplified. As a standard fatigue load spectrum, the standard fatigue load model is generated by an appropriate method. However, there is no unified standard for how to establish the corresponding train load model based on the measured data, which makes the fatigue load model modeling method based on the measured data imperfect.

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