Multistage damage detection of a transmission tower: Numerical investigation and experimental validation

Abstract

When vibration-based damage detection methods are applied to a large transmission tower for damage detection of loosened bolts, a number of obstacles exhibit. The global stiffness matrix, modal parameters, and global dynamic responses are not sensitive to local damage (loosened bolts) of a large transmission tower. The one-stage damage detection is inaccurate and sometimes impossible due to too many unknown damage parameters and seriously illconditioned inversed problem for a large transmission tower. Therefore, a new multistage damage detection method incorporating with a multiscale finite element (FE) model and a multitype sensor placement is proposed in this paper for the damage detection of loosened bolts of a large transmission tower.The methodology of multistage damage detection of the transmission tower with loosened bolts is first introduced. The numerical study with the multiscale FE model and the multitype sensor placement is then conducted to demonstrate the feasibility and accuracy of the multistage detection method using a large transmission tower testbed. The experimental validation is finally performed on the testbed to ascertain the effects of uncertainties involved in the numerical study on damage detection results. Both the numerical and experimental studies manifest that the proposed multistage detection method can effectively identify the loosened bolts in a joint of the transmission tower. KEYWORDS large transmission tower, loosened bolts, multi-scale finite element model, multi-stage damage detection, multi-type sensor placement

Vibration Anatomy and Damage Detection in Power Transmission Towers with Limited Sensors

“…In this method, wavelet packet energy and modal strain energy of the structure were used as a damage indicator. Xu et al [2] proposed a multi-stage procedure based on the covariance matrix of the dynamic response of the structure for damage detection in the connections of the power transmission towers. The main drawback of this procedure was the large number of applied sensors, which makes it expensive and impractical in a majority of cases.…”

“…In the method proposed by Xu et al [2], a total of 22 instruments (including 15 accelerometers and 7 strain gauges) were used for tower damage detection. This method used a discrete damage index for each sensor location.…”

“…Such towers are not only damageable against the wind loads, the world-wide experiences show their vulnerability subjected to earthquake ground motions and storm events, as well. Figure 1 illustrates the potential failures under wind and earthquake loading [2,3]. Despite several studies that have studied the vibration characteristics of towers under earthquake and wind loads [4], the health monitoring of these structures has received limited attention, especially from industrial practices.…”

Aeolian vibration‐based structural health monitoring system for transmission line conductors

“… is the acceleration of motion; is the speed, and x is the displacement. According to Equation , scholars can identify the structural changes from the vibration response, such as structural health monitoring on transmission towers and offshore pipelines . In terms of the transmission line conductor, when a strand breaks, the vibration response changes.…”

Structural Damage Diagnosis-Oriented Impulse Response Function Estimation under Seismic Excitations

“…However, the updated results were subject to the effect of measurement noise. More recently, Lin and Xu [15][16][17][18][19] proposed a covariance-based multi-sensing damage detection method with optimal sensor placement in which the damage index was sensitive to local damage but insensitive to measurement noise. Other researchers also developed data-driven damage detection methods incorporating artificial intelligence algorithms [20][21][22][23][24][25][26].…”