Damage detection of concrete segment in steel-concrete hybrid wind turbine tower

The steel–concrete hybrid tower (SCHT) has been applied as an alternative supporting structure for wind turbines due to its advantages of higher hub height and loading bearing capacity. To improve the construction efficiency of such a tower on site, the lower concrete section was divided into several prefabricated segments and the connection between different segments was achieved by grouting joints, which may become the weakest part of the tower under the combined action of compression, bending, shear and torsion, leading to progressive collapse or other undesirable failures of the SCHT. However, up to now, there were limited studies focused on the monitoring system detecting the damage of the concrete segment and most of them required inspection at downtime. To fill up the research gap, this paper developed a real-time monitoring system for detecting the possible failure of the concrete segment effectively and accurately. To start with, the formulation of the damage index based on the dynamic acceleration responses is firstly presented based on the mechanical characteristics of the wind turbine towers. Then, an experimental investigation and parametric analysis based on numerical simulation are arranged to validate the reliability of the proposed method. The analysis results indicate the proposed method can provide a reference for the damage monitoring of the SCHT.