Multi-modal flexibility simultaneous recognition method and system based on rotation angle measurement

Abstract

The invention discloses a multi-modal flexibility simultaneous recognition method based on rotation angle measurement. The method comprises the following steps: collecting and storing dynamic rotation angle displacement response of an engineering structure under environmental excitation; recognizing a basic modal parameter, a macro strain vibration mode and a vertical displacement vibration mode; normalizing the angular displacement vibration mode and the vertical displacement vibration mode by using the mass matrix distribution of the measurement structure, and realizing generalized displacement modal flexibility recognition in combination with the basic modal parameters; mass normalization is carried out on the recognized macro strain vibration mode, and macro strain variable frequency response function reconstruction and macro strain modal flexibility recognition of the structure are realized; and multiplying the recognized generalized displacement modal flexibility matrix and the macro strain flexibility matrix by any static load vector acting on the structure, and predicting the response of the structure under the static load, thereby realizing the state evaluation of the engineering structure. The method has the advantages of test cost saving, convenience and quickness, monitoring data can be practically and effectively mined, and a data foundation is laid for structural safety state evaluation.

Description

technical field [0001] The invention belongs to the technical field of structural health monitoring, and in particular relates to a method and system for simultaneously identifying multiple modal flexibility based on rotation angle measurement. Background technique [0002] my country's bridge construction has achieved world-renowned achievements, but bridge collapse accidents occur from time to time, causing serious economic losses and heavy casualties. How to ensure structural safety and longevity is a major national demand. Using structural intelligent detection and monitoring technology to detect structural diseases and hidden dangers in time is expected to solve bridge safety problems. Structural technical condition assessment based on regular inspection is the main means to evaluate the current service performance of bridges in my country. Guided by the "Technical Specifications for Urban Bridge Maintenance" issued by the Ministry of Construction and the "Specificatio...

AI Technical Summary

Problems solved by technology

Regular inspection method is the main means of existing bridge maintenance, but it is mainly manual, time-consuming and labor-intensive

[0003] Structural health monitoring technologies based on various types of advanced sensors play an active role in early warning of emergencies. However, existing data analysis methods mainly identify basic modal parameters such as structural natural frequencies, damping ratios, and displacement modes. Unable to truly realize structural health monitoring

In addition, the environmental vibration test widely used in the field of structural health monitoring relies on a single sensing method, and only a single type of structural parameter can be identified from the monitoring data. For example, the acceleration sensor can only identify the natural frequency, damping ratio and displacement vibration of the structure. type; only the frequency, damping ratio, and strain mode shape can be identified using the strain sensor

Therefore, it is necessary to install multiple types of sensor systems on the structure to fully grasp the performance status of the structure. The health monitoring system is large in scale, complex and expensive.

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