Unit temperature response monitoring value based correction method for finite element model of large-span steel bridge

Abstract

The invention discloses a unit temperature response monitoring value based correction method for a finite element model of a large-span steel bridge. The method comprises the following major steps of 1) analyzing annual monitoring data of the large-span steel bridge and determining static strain and displacement generated by unit uniform temperature change based on a relative probability histogram of a structure response value during unit temperature change; 2) establishing a primary finite element model according to design data; 3) preliminarily determining the horizontal stiffness of a steel bridge support by adopting an iterative method; 4) performing sensitivity analysis on the large-span steel bridge based on actual measurement data of displacement at the large-span steel bridge support and strain in a key position, and determining a design variable with a relatively high coefficient of correlation with the actual measurement data; and 5) performing optimization analysis on the finite element model of the large-span steel bridge by reducing a difference value of a finite element calculation result and the actual measurement data. Compared with a generally adopted finite element model correction method based on dynamic response results of test modal data and the like, the method has the advantages of simplicity, accuracy, relatively low expense and high security.

Description

technical field [0001] The invention belongs to the field of civil engineering numerical simulation analysis, and relates to a correction method for a finite element model of a long-span steel bridge based on a unit temperature response monitoring value. Background technique [0002] With the rapid development of the national economy, the construction of large bridges in our country is speeding up. Steel bridges are widely used in long-span bridges due to their strong spanning ability and fast construction speed, and play a key role in the local environment, economy and social life. Long-span steel bridges have large spans, various types of components, and complex structural layouts. Due to adverse factors such as environmental loads, fatigue effects, and material aging, various defects will inevitably appear in bridges during long-term use, resulting in the accumulation of damage to local key components of the structure. If the decrease in stiffness and bearing capacity o...

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Problems solved by technology

However, in the process of building the model, there are errors in boundary conditions, material and section parameters, mass and load distribution, etc., making it difficult for the finite element model to accurately reflect the behavior and working state of the structure under service loads. It is necessary to use a health monitoring system The finite element model is corrected by the response monitoring value of the finite element model, so that the further safety assessment of the bridge can be carried out through the corrected finite element model

[0004] At present, the dynamic response results such as test modal data are generally used to correct the finite element model of long-span steel bridges. Although the modal test based on environmental excitation is widely used in recent years, it is safe and does not affect the normal use of the bridge. There are many deficiencies: 1) There are unknown inputs in the environmental excitation, such as various noise disturbances; 2) The modal parameter identification is based on the assumption of modal theory; 3) The local response of the structure cannot be determined; 4) The precise modal parameter identification requires more High, the amount of data processing is large, which is not conducive to engineering personnel to master; 5) The number of sensors requires more

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