Experimental Verification of the Local Damage Detection Method Based on Spatial-temporal Correlation in Dense Sensor Networks

Abstract

Structures get local damaged during their daily service or natural disaster like earthquakes and hurricanes. Local damage will gradually develop and grow, which will lead to the overall damage of the structure, and even lead to the collapse. Therefore, local damage detection plays an important role in ensuring structural safety and lifecycle maintenance of structures. In response to this phenomenon, the paper propose a new local damage detection method based on spatial-temporal correlation in dense sensor networks without the need for exact knowledge of structural properties. Firstly, the structural response is collected by sensor networks. The collected response is then used to analyze spatial-temporal correlation between the responses of different points. The damage indicator in the paper is called the angle coefficient, which measures the angle between regressed plans from two different states of the system. To ensure accurate detection of local damage, coefficient of determination is used in the paper to evaluate the reliability of angle coefficient, and chooses angle coefficients with higher coefficient of determination to detect structural damage. The performance of proposed method was verified through a dynamic excitation experiment on a scaled model of twostory assembled frame structure. The frame structure was constructed at the State Key Laboratory for Disaster Reduction in Civil Engineering at Tongji University. There are 7 cases in the experiment, including three different damage degrees. According to the structural response collected from the experiment, the angle coefficient is calculated to detect local damage in the system. The results show that the proposed method can successfully detect local damage and its location in the structure, even at a complex environment. Comparing influence coefficients of different damage degrees, it can be found that there is a certain positive correlation between angle coefficient and damage degree of the structure. That is, the greater the damage degree is, the higher the angle coefficient is.