The structural characteristics of the transition piece (TP) and its behavior are greatly affected the performance and safety (life) of the supporting structure of offshore wind turbines (OWT).
This study was included in the second phase of the National Energy Project (NEP-II), Taiwan, and studying the structural behavior and fault features of TP on the OWT of FOWI. The vibration monitoring of the supporting structure of OWT is accompanied by signal analyzing to obtain structural behavior and then catch the damage mechanism for monitoring.
Lecture review on the behavers and damage features of TP were included. An in-suite structural vibration monitoring of OWT was included also the time-frequency analysis (TFA) results for the realization on studying issues.
The mono-pile foundation with grouted connections (GC) are not only widely used in the oil and gas industry, but also the wind energy supporting structures nowadays. It provides an efficient solution to join the pile driven into the seabed and the sub-part of the supporting structure. However, since late 2009, unexpected settlements of the transition piece (TP) relative to the mono-pile (MP) have been reported in many of the plain-pipe grouted connections for offshore wind turbine generator (WTG) constructed pre-2010. This has increased the likelihood of lost operation and structural failure and resulted in extensive remedial woks to relieve such grouted connections from damage accumulation. This definitely would directly has impact on the performances of wind turbines in the coming future offshore Taiwan. Therefore timely detection of these problems is vital.
From the aspect of structure health monitoring (SHM), the loss of functionality of grouted connections can be detected theoretically. Nonetheless, related research literatures in this specific area are few. In this study, methods and strategies based on continuous identification of natural frequencies and transfer functions of the wind turbine structure are proposed for estimating the loss of functionality of the grout connections.
This study briefly make a literature review, investigate the mechanics of grout connections, and conceptually describe the development of the proposed method for monitoring the robustness of GC.