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A novel finite element model updating method considering environmental conditions

Many studies have shown that structure’s dynamic properties have a strong correlation with environmental influences, such as temperature and wind speed. For example, researchers from Los Alamos National Laboratory found that the first natural frequency of the Alamosa Canyon Bridge varied about 4.7% during a 24-hour period as the temperature of the bridge deck changed by approximately 40℉. In Europe, Peeters and De Roeck monitored the Z24 Bridge during one-year period and reported that the environmental changes caused 14-18% variation of the first 4 natural frequencies. In Japan, Siringoringo and Fujino reported 4.6% and 2.2% change for the 1st and 2nd natural frequencies of Hakucho Bridge under wind speed change from 3 to 15 m/s. Not fully recognizing these real world complexities brought by environmental impacts subsequently creates uncertainties or even misinterpretation in model updating and damage detection.

Currently, data-driven models, for instance, regression models between natural frequencies and environmental conditions (e.g., temperature and wind speed) are used to remove environmental impacts on the measured natural frequencies. This paper presents a novel finite element model updating method that is taking a different approach. It aims to consider environmental impacts during the updating procedure. Numerical study is conducted to demonstrate the proposed FE model updating method is capable to provide accurate model updating results even under environmental impacts. Several damage scenarios with different damage distributions combined with environmental conditions will be considered in the numerical study to examine the proposed updating method.

Author(s):

Wei Song    
The University of Alabama
United States

Shanglian Zhou    
The University of Alabama
United States