RISK-BASED IN-SERVICE INSPECTION FRAMEWORK FOR OFFSHORE CONCRETE WIND TURBINE STRUCTURES AND APPLICATION OF FUZZY INFERENCE SYSTEM

Risk-based in-service inspection enhances structural integrity and minimizes the number of potential unwanted incidents in relation to offshore concrete wind turbine structures. Risk-based in-service inspection enables in-situ inspections, evaluation of inspection results, condition assessment of the offshore wind turbine structures and recommends optimal future inspections. The vagueness, uncertainties and variability present in the risk-based in-service planning process jeopardizes the final inspection recommendations and structural integrity of the structure under consideration. Hence, it is vital to develop methodologies for the systematic utilization of expert knowledge to minimize variability in risk-based in-service assessments. This manuscript suggests a fuzzy set theory-based approach to minimize the risk assessments' variability and unwanted activities. The suggested fuzzy set theory-based approach enables the identification of the potential hot points that encompass high-risk regions needing priority in future inspections with optimal effort and higher productivity. This manuscript also discusses the use of available inspection methods to enhance the structural integrity of offshore concrete wind turbines subject to deterioration, as well as the use of fuzzy theory-based risk-based in-service inspection assessments for making optimal in-service inspection recommendations.