PSI - Issue 22

Sophia Metaxa et al. / Procedia Structural Integrity 22 (2019) 369–375 Sophia Metaxa/ Structural Integrity Procedia 00 (2019) 000 – 000

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account the prevention of such imperfections, especially in areas where stress concentration is observed. However, it is commonly accepted and taken for granted that such defects exist in any given structure [2]. 6. Applications Health monitoring and assessment techniques has captured attention of researchers owing to their potential in providing spatial and quantitative information regarding structural damage and the reassurance of expected performance of a structure during its operational lifespan. This monitoring method, although not widespread, mainly aims to maintain the integrity of major projects; The paragraph is aimed at investigating current technologies, planning for implementation, and identifying costs and feasibility of structural monitoring in the future. With the depletion of fossil energy, offshore wind power has become an irreplaceable energy source for most countries in the world. In recent years, offshore wind power generation has presented the gradual development trend of larger capacity, taller towers, and longer blades. The more flexible towers and blades have led to the structural operational safety of the offshore wind turbine (OWT) receiving increasing worldwide attention. From this perspective, health monitoring systems and operational safety evaluation techniques of the offshore wind turbine structure, including the monitoring system category, data acquisition and transmission, feature information extraction and identification, safety evaluation and reliability analysis, and the intelligent operation and maintenance, were systematically investigated and summarized. In conclusion, it was possible to identify that deformation and displacement sensors, along with optical and electrical technologies are the most commonly used types of sensors. This monitoring method, although not widespread, mainly aims to maintain the integrity of major projects; it is not currently focused in small sized works, with the exception of a few structures of historical interest. Particularly, the offshore wind power industry will continue to develop into deep ocean areas in the next 30 years in China. Practical and reliable health monitoring systems and safety evaluation techniques are increasingly critical for offshore wind farms. Simultaneously, they have great significance for strengthening operation management, making efficient decisions, and reducing failure risks, and are also the key link in ensuring safe energy compositions and achieving energy development targets worldwide. Pipeline inspection technologies using sensor networks have drawn significant attention, in the applications of natural gas pipeline inspection and monitoring. To ensure the continued safe operation of the transmission pipelines, continuous monitoring or periodic assessment of the integrity of the pipelines is necessary. In pipeline monitoring and inspection, the ultimate objective is to identify the locations that has defects, and obtain an accurate measurement and assessment of the defects so that operators can take appropriate actions to prevent further damage. The development of multi-sensor tools is essential for both the location and condition assessment of pipelines [1]. Distributed fiber sensors technology is widely used now a days for pipeline monitoring. The research advancements carried out using these sensors is briefly presented. Recent advancements on corrosion and leakage detection using latest sensing technologies is also presented. It is deemed obligatory to monitor energy production systems so as to obtain operational performance reassurance. Health Monitoring of such structures has gained much interest lately as it offers enhanced safety, optimized inspection cycles by the use of non-destructive testing techniques, minimization of downtime and avoidance of extended damage. Such facilities must be routinely monitored to ensure good condition to ultimately provide reliable and hazard-free power generation [4]. Various existing measurement techniques, including fibre-optics, and the acoustics emission, can detect and identify defects posing a threat (Fig.1).

Fig. 1. Experimental implementation of FBG optical fibres towards structural health monitoring [10]