Open Access

ABSTRACT

Modal identification of structure under varying environmental conditions

by Deyi Zhang¹, Yuequan Bao, Feng Zhou, Hui Li

1 School of Civil Engineering, Harbin Institute of Technology, Harbin, 150090, China. Email:zhangdeyi@hit.edu.cn

The International Conference on Computational & Experimental Engineering and Sciences 2009, 12(2), 65-72. https://doi.org/10.3970/icces.2009.012.065

Abstract

Modal identification is essential in structural health monitoring (SHM) because that the modal parameters are often used for model updating and damage detection. However, in practical situations, the variation of environmental conditions (e.g. temperature, temperature gradients, humidity, etc.) will impede the reliability of modal identification. In this paper, firstly, the relation of frequency change and variation of environment temperature of space structure is investigated. Then, a structural state assessment method by combing autoregressive moving average (ARMA) and PCA is proposed. The acceleration data from China National Aquatics Center is employed as an example. The results show that variation of frequencies with increasing of temperature and wind velocity is not notable. That is because the temperature difference and velocity variation are little.

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