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A damage early warning method for civil engineering structures considering the influence of temperature

A civil engineering structure and structural damage technology, applied in the direction of instrument, calculation, electrical digital data processing, etc., can solve the problem of not considering the influence of temperature on the early warning of civil engineering structure damage, and achieve novel methods, strong operability, theoretical rigorous effect

Active Publication Date: 2016-08-17
QINGDAO TECHNOLOGICAL UNIVERSITY
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AI Technical Summary

Problems solved by technology

First, the AR model coefficients before and after structural damage are extracted to form multiple original data matrices; secondly, principal component analysis is performed on multiple original data matrices to obtain the first two-order principal components, and corresponding ellipse control charts are established. The distribution in the control ellipse is used to judge whether there is damage to the structure, but this method does not consider the influence of temperature on the damage warning of civil engineering structures

Method used

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  • A damage early warning method for civil engineering structures considering the influence of temperature
  • A damage early warning method for civil engineering structures considering the influence of temperature
  • A damage early warning method for civil engineering structures considering the influence of temperature

Examples

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Effect test

Embodiment 1

[0051] A damage warning method for civil engineering structures under the influence of temperature factors, the specific steps are as follows:

[0052] (1) Build AR model:

[0053]

[0054] In the formula, p represents the model order, is the autoregressive coefficient (AR model coefficient), Indicates the "historical value" X at time t-i t-i For the value X at time t t Contribution or influence, {ɑ t} means 0 and variance σ ɑ 2 white noise sequence;

[0055] (2) By carrying out principal component analysis to the above-mentioned AR model coefficients, the method of seeking the residual error of the principal component analysis results reduces the impact of ambient temperature on the AR model coefficients;

[0056] a) Assuming a sample matrix Y∈R constructed from AR model coefficients n×N , perform singular value decomposition on the covariance matrix of the sample matrix Y:

[0057] YY T =USUT (2)

[0058] In the above formula, U is an orthogonal matrix, that...

Embodiment 2

[0079] A three-dimensional finite element model of a four-layer framework is established by using ANSYS, such as figure 1 As shown, the basic parameters: the density is 7800Kg / m 3 , Poisson's ratio μ=0.3. Columns, beams and supports use BEAM4 unit, the roof adopts SHELL63 unit, and the accumulation mass on the roof adopts MASS21 unit for simulation.

[0080] The model has a total of 32 nodes, 192 degrees of freedom, 50 BEAM4 units, 1 SHELL3 unit, 4 MASS21 units, 7 unit section types, and the model is fixed to the foundation.

[0081] In this example, the diagonal braces on the Y-direction surface II (6) are damaged to different degrees as the research object. The damage is realized by the reduction of the elastic modulus. The temperature range is -20°C to 40°C. The elasticity of the steel Modulus and temperature relationship as figure 2 shown.

[0082] The numerical simulation considering the influence of temperature is realized by setting the elastic modulus of the struc...

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Abstract

The invention relates to the field of civil engineering structure damage identification, in particular to a civil engineering structure damage early warning method considering the influence of temperature, using the AR model in the time series analysis and the principal component analysis in the multivariate statistical analysis combined with the standard deviation control chart to carry out structural Injury early warning research. Firstly, the AR model is used to fit the acceleration response data before and after the structural damage, and the model coefficients are extracted. Secondly, the influence of temperature on the AR model coefficients is removed by principal component analysis. Finally, the standard deviation control chart is used for damage warning. The invention has rigorous theory, novel method, reasonable scheme and strong operability. The advantage of this method is that it directly uses the acceleration response without the need for finite element models and modal parameters. It is a data-driven method and is suitable for real-time structural health monitoring. At the same time, this method has excellent anti-noise ability under the condition of temperature changes. , the damage warning was successfully carried out.

Description

technical field [0001] The invention relates to the field of civil engineering structure damage identification, in particular to a civil engineering structure damage early warning method considering the influence of temperature. Background technique [0002] Structural damage will cause changes in the characteristic parameters of the dynamic response, and changes in temperature will also cause changes in the characteristic parameters of the dynamic response, and sometimes even overwhelm the changes in the characteristic parameters of the dynamic response caused by damage, which will lead to the failure of the structural damage identification method based on vibration . [0003] Wu Sen et al., Damage Identification Method Based on AR Model and Principal Component Analysis, Vibration, Testing and Diagnosis, 2012.10, 32(5), 847-845. A damage identification method based on structural acceleration time series was proposed. First, the AR model coefficients before and after struct...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F19/00
Inventor 刁延松任红陈家宝曹亚东孙玉婷华盼盼徐东锋
Owner QINGDAO TECHNOLOGICAL UNIVERSITY
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