Design Optimization of Conical Concrete Support Structure for Offshore Wind Turbine

Abstract

Various types of support structures for offshore wind turbine have been developed, and concrete structures have attracted attention due to many advantages. Although many studies have been conducted on the design of the existing steel structures, information and research on the design of concrete support structures are insufficient. Therefore, in this paper, a structural analysis model of conical concrete support structure (CCSS) is established and design optimization is presented. A detailed performance evaluation and the design of prestressed concrete were performed under the marine conditions of Phase 1 test site of southwest offshore wind project in Korea. The fluid–soil–structure interaction (FSI) was applied using the added mass method and soil spring model to represent the effects of water and soil. With the result of quasi-static analysis, a post-tensioning design was implemented by applying prestressing steel, and CCSS showed sufficient rigidity. From the natural frequency analysis, CCSS has a dynamic structural stability, and, in response spectrum and time-history analyses, the CCSS was safe enough under the earthquake loads. The methods and conclusions of this study can provide a theoretical reference for the structural analysis and design of concrete support structures for offshore wind turbines.

The Beneficial Effect of the Addition of Fly Ash on Reduction of the Size of Microcracks in the ITZ of Concrete Composites under Dynamic Loading

“…The observed cracks were caused by the impact loads. As a result of this, the image of formation of damages in the specimens and the manner of their destruction, already at the stage of the evaluation of the obtained results, looked different from the case when the same cubes were tested under static load [28,54,73]. The following were analyzed:…”

“…However, the results presented in [50] relate to concretes subjected to static loads only. However, it should be emphasized that the situations when it is necessary to take into account dynamic loads in the analyses of concrete structures are numerous, e.g., [51][52][53][54][55][56][57][58][59][60][61]. Their summary is presented in detail in Section 2.…”

Impacts of Mooring-Lines Hysteresis on Dynamic Response of Spar Floating Wind Turbine

“…Chen [5] developed an innovative hybrid foundation and investigated its behavior under static and dynamic loadings, and the results showed that addition of the bucket to the foundation can restrain the rotation and lateral displacement effectively. Kim [6] established an analysis model of a conical concrete support structure and optimized the design parameters the response spectrum and time-history analyses showed that the support was safe enough under the earthquake loads.…”