Method for node rigidity prediction based on vibration measurement

Abstract

The invention relates to a method for node rigidity prediction based on vibration measurement. The method is characterized by comprising the steps of first establishing a node model (a finite element model or a test model), utilizing the model to enable a first principal component score extreme value obtained through generalized likelihood ratio principal component analysis to serve as a control index, and establishing a relation curve of the proportion of the control index exceeding the upper limit and the lower limit and node rigidity under different damage working conditions in a statistical quality control chart; in actual engineering, measuring vibration response of a node, and calculating the proportion of the control index exceeding the upper limit and the lower limit in the statistical quality control chart according to the response; and finally substituting the proportion of the control index exceeding the upper limit and the lower limit into the relation curve to predict the node rigidity. According to the method, the node rigidity can be rapidly and effectively predicted without needing other data, only acceleration response of a structure needs collecting, and the method can be used for structural ageing and after-calamity rapid prediction.

Description

technical field [0001] The present invention relates to a technology for predicting node stiffness, in particular to a technology for predicting node stiffness during use of a structure, namely a node stiffness prediction method based on vibration test. Background technique [0002] In order to avoid the vicious collapse of bridge piers, improve its dynamic characteristics, and reduce long-term comprehensive maintenance costs, bridge damage identification and assessment based on dynamic testing has become a research hotspot. However, various structural damage diagnosis methods based on vibration testing have their own limitations. Since only a few first-order frequencies and mode shapes of the structure can be obtained in the actual test conditions, it is necessary to directly use the frequency or mode shape for damage identification. less precise. For this reason, many scholars seek a change of an index sensitive to injury to diagnose injury. That is, the current state is...

AI Technical Summary

Problems solved by technology

At the beginning of this century, some scholars proposed that the structural damage identification technology using statistical knowledge has been developed, but it still has the following problems: (1) The current index that uses statistical knowledge is mainly considered to be the acceleration itself, but the acceleration itself is affected by the environment. Unreliable indicators for large problems; (2) Structural damage techniques using statistical knowledge cannot be combined with structural stiffness

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