Civil engineering structure damage pre-warning method in consideration of temperature influence

A civil engineering structure and environmental temperature technology, which is applied in the fields of instrumentation, calculation, electrical digital data processing, etc., can solve the problems of not considering the influence of temperature on the early warning of civil engineering structure damage, and achieves novel methods, rigorous theory, and operability. strong effect

Active Publication Date: 2014-03-19
QINGDAO TECHNOLOGICAL UNIVERSITY
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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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  • Civil engineering structure damage pre-warning method in consideration of temperature influence
  • Civil engineering structure damage pre-warning method in consideration of temperature influence
  • Civil engineering structure damage pre-warning method in consideration of temperature influence

Examples

Experimental program
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Effect test

Embodiment 1

[0050] A damage warning method for civil engineering structures under the influence of temperature factors, the specific steps are as follows:

[0051] (1) Build AR model:

[0052]

[0053] 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;

[0054] (2) By performing principal component analysis on the above AR model coefficients and calculating the residual error of the principal component analysis results, the influence of ambient temperature on the AR model coefficients can be reduced;

[0055] 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:

[0056] YY T =USU T (2)

[0057] In the above formula, U is an orthogonal matrix, that is, ...

Embodiment 2

[0077] 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.

[0078] 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.

[0079] In this example, the oblique braces on the Y-direction surface II (6) are damaged to different degrees as the research object. The damage is achieved through the reduction of the elastic modulus. The temperature range is -20°C to 40°C. The elasticity of steel Modulus and temperature relationship as figure 2 shown.

[0080] 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 pre-warning method in consideration of a temperature influence. An AR model in time series analysis and principal component analysis in multivariate statistical analysis are utilized, and a standard deviation control chart is combined for structure pre-warning research. Firstly, accelerated speed response data before and after structure damage are fit by the AR model, and a model coefficient is extracted; secondarily, the influence of temperature on the AR model coefficient is removed through principal component analysis; and finally, damage pre-warning is performed by using a standard deviation control chart. The pre-warning method is rigorous in theory, novel, reasonable in scheme and high in operability. The civil engineering structure damage pre-warning method has the advantages that accelerated speed response is directly used, a finite element model and modal parameters are not required, and the method belongs to a data driving method and is suitable for performing structure health monitoring in real time; and simultaneously, according to the method, under the condition of temperature change, the damage pre-warning is successfully performed through the anti-noise capacity.

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 struc...

Claims

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Application Information

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Patent Type & Authority Applications(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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