Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Results
Committee I.2: Loads
Hermundstad, Ole Andreas (_) | Chai, Shuhong (_) | de Hauteclocque, Guillaume (_) | Dong, Sheng (_) | Fang, Chih-Chung (_) | Johannessen, Thomas B. (_) | Morooka, Celso (_) | Oka, Masayoshi (_) | Prpic-Oršic, Jasna (_) | Sacchet, Alessandro (_) | Sazidy, Mahmud (_) | Ugurlu, Bahadir (_) | Vettor, Roberto (_) | Wellens, Peter (_)
Committee Mandate Concern for the environmental and operational loads from waves, wind, current, ice, slamming, sloshing, green water, weight distribution and any other operational factors. Consideration shall be given to deterministic and statistical load predictions based on model experiments, full-scale measurements and theoretical methods. Uncertainties in load estimations shall be highlighted. The committee is encouraged to cooperate with the corresponding ITTC committee. Introduction The content of this committee's report is composed in accordance with its mandate by the expertise of its members. Compared to previous reports of the Loads committee the structure is slightly altered, while the topics covered remain basically the same, except that the present report covers ice loads more extensively, while giving less attention to hydroelasticity in waves. There is one section for each of the main types of loads acting on a ship or offshore structure. Hence, Section 2 focuses on wave loads, Section 3 on current and wind loads, while Section 4 concerns ice loads. Next, Section 5 is of a more generic character, concerned with characteristic loads and uncertainty. Finally, Section 6 is devoted to special topics, of which there was only one contribution, namely loads on free-fall lifeboats. Within each of the sections 2 – 5 there is generally one part focusing on ships and another part focusing on stationary offshore structures. On the lowest level we have distinguished between the different ways of assessing the loads, namely theoretical/numerical methods, laboratory tests and full-scale measurements, although this subdivision is not followed consistently through all sections. In the section on wave loads, a distinction is made between potential theory methods and field methods. The latter group contains numerical methods for solving the Navier-Stokes equations in some form, assessing the flow in the entire fluid field. Potential formulations normally use boundary element methods, although field methods can also be used with potential theory (e.g, Amini-Afshar et al. 2019). The committee has performed a benchmark study on heave/pitch motions and vertical bending moments for a large containership at zero speed in steep regular waves. Existing experimental results have been compared with numerical simulations performed by some of the committee members to investigate the performance of various numerical linear and nonlinear methods, ranging from strip theories to SPH and RANSE solvers. This study is presented in an appendix to the report. To avoid unnecessary overlap with other ISSC committees the focus has been on loads and rigid body responses. Structural dynamic responses, such as springing and whipping of ships, are left to the Dynamic Response Committee, but vortex-induced vibrations of slender structures and ice-induced vibrations are considered in the present report. Loads on offshore wind turbines (OWT) are covered to some extent, although the Offshore Renewable Energy Committee deals with OWT in general.
- North America > United States (1.00)
- Europe (1.00)
- Asia > China (0.67)
- Research Report > New Finding (1.00)
- Research Report > Experimental Study (1.00)
- Overview > Innovation (0.92)
- Transportation > Marine (1.00)
- Energy > Renewable > Wind (1.00)
- Energy > Renewable > Ocean Energy (1.00)
- (4 more...)
- Europe > Denmark > North Sea > Danish Sector > Central Graben > Block 5504/12 > Tyra Field (0.99)
- Europe > Denmark > North Sea > Danish Sector > Central Graben > Block 5504/11 > Tyra Field (0.99)
- North America > United States > Colorado > Ice Field (0.98)
Committee V.4: Offshore Renewable Energy
Kolios, Atanasios (_) | Kim, Kyong-Hwan (_) | Cheng, Chen Hsing (_) | Oguz, Elif (_) | Morato, Pablo (_) | Ralph, Freeman (_) | Fang, Chuang (_) | Ji, Chunyan (_) | Le Boulluec, Marc (_) | Choisnet, Thomas (_) | Greco, Luca (_) | Utsunomiya, Tomoaki (_) | Rezanejad, Kourosh (_) | Rawson, Charles (_) | Rodrigues, Jose Miguel (_)
Committee Mandate Concern for load analysis and structural design of offshore renewable energy devices. Attention shall be given to the interaction between the load and structural response of fixed and floating installations taking due consideration of the stochastic and extreme nature of the ocean environment. Aspects related to design, prototype testing, certification, marine operations, levelized cost of energy and life cycle management shall be considered. Introduction This is the sixth time that ISSC has included the Specialist Committee V.4 Offshore Renewable Energy, which started in 2006. Two members of the committee for this term (2018-2022) were involved in the work for the previous term (2016-2018), which formulates a good base for the cooperative work in the last three years. The mandate of the committee was discussed at the beginning of the work, and it was slightly modified to include extreme environmental conditions and interaction of structures to the seabed, reliability-based design, safety and integrated design, topics which have been central to the discussion for developing offshore renewable energy, and hence should be discussed in the committee report. Another variation of this committee’s report has been the consideration of floating wind developments in a separate chapter as deployments are currently moving further offshore and in deeper waters, as well as the explicit reference to hybrid solutions. Offshore wind energy still dominates offshore renewable energy technologies with extensive installed capacity and ambitious targets which constitute this technology as a key contributor towards the ambitious 2050 net zero emissions targets. For these targets to be achieved, it is imperative to innovate and further develop not only wind energy but also other offshore, marine and hybrid energy technologies, harvesting as much as possible the energy potential. Challenges related to wind energy include, among others, the upscaling at both a unit as well as a farm level, development of foundations relevant to deep waters, serial production of floating foundations and effective mooring systems, and investigation of support systems to inform end-of-life scenarios including service life extension, repowering or decommissioning. Marine renewables on the other hand, still need to overcome challenges related to structural response in extreme phenomena and reliability of mechanical components which sharply escalate the levelized cost of energy. Within this report we have considered peer reviewed academic articles, selected conference proceedings and some reference industry reports. Overall, more than 500 sources have been reviewed and 350 have eventually qualified to be included in this state-of-the-art review. The time span of the review includes contributions from August 2017 to August 2021. The term of this committee has been extended due to the COVID-19 pandemic. The report has been organized into 9 subsections. Following this short introduction, a session on bottom fixed wind turbines is included, following the structure of the previous committee’s report, with the addition of design provisions for extreme phenomena which are particularly relevant in South-East Asia and a subsection on advanced structural analysis. Next, a dedicated section on floating wind turbines is included, following a similar structure, with the addition of moorings and dynamic cables which is relevant to this class of foundations. Next three subsections present developments on wave energy converters, tidal and ocean current turbines, and other offshore renewable energy technologies and hybrid solutions. Following this, a subsection on life-cycle cost and operational management of offshore renewable energy is presented, identifying key cost elements that attract attention for research and development. Section 8 summarizes the efforts of the committee members to investigate a benchmarking study on the comparison of the existing design guidelines with respect to design of mooring systems. Finally, the last section of the report lists some conclusions which stem out of the review and key challenges that research should try to address in the next few years.
- North America > United States (1.00)
- Asia > China (1.00)
- Europe > United Kingdom > Scotland (0.46)
- Research Report > New Finding (1.00)
- Overview (0.92)
- Research Report > Experimental Study (0.67)
- Energy > Renewable > Wind (1.00)
- Energy > Renewable > Ocean Energy (1.00)
- Health, Safety, Environment & Sustainability > Sustainability/Social Responsibility > Sustainable development (1.00)
- Health, Safety, Environment & Sustainability > Environment (1.00)
Design for preventing or minimizing the effects of accidents is termed accidental limit states (ALS) design and is characterized by preventing/minimizing loss of life, environmental damage, and loss of the structure. Collision, grounding, dropped objects, explosion, and fire are traditional accident categories.
- South America > Brazil (1.00)
- Oceania > Australia (1.00)
- North America > Canada (1.00)
- (11 more...)
- Summary/Review (1.00)
- Research Report > New Finding (1.00)
- Research Report > Experimental Study (1.00)
- (3 more...)
- Geology > Mineral (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Sedimentary Geology > Depositional Environment (0.67)
- Geology > Structural Geology > Tectonics > Plate Tectonics (0.67)
- Transportation > Marine (1.00)
- Transportation > Infrastructure & Services (1.00)
- Transportation > Ground (1.00)
- (36 more...)
- South America > Brazil > Campos Basin (0.99)
- North America > United States > Gulf of Mexico > Central GOM > East Gulf Coast Tertiary Basin > Viosca Knoll > Block 786 > Petronius Field (0.99)
- North America > United States > Gulf of Mexico > Central GOM > East Gulf Coast Tertiary Basin > Mississippi Canyon > Block 392 > Appomattox Field (0.99)
- (58 more...)
"In offshore and coastal engineering, metocean refers to the syllabic abbreviation of meteorology and (physical) oceanography" (Wikipedia). Metocean research covers dynamics of the oceaninterface environments: the air-sea surface, atmospheric boundary layer, upper ocean, the sea bed within the wavelength proximity (~100 m for wind-generated waves), and coastal areas. Metocean disciplines broadly comprise maritime engineering, marine meteorology, wave forecast, operational oceanography, oceanic climate, sediment transport, coastal morphology, and specialised technological disciplines for in-situ and remote sensing observations. Metocean applications incorporate offshore, coastal and Arctic engineering; navigation, shipping and naval architecture; marine search and rescue; environmental instrumentation, among others. Often, both for design and operational purposes the ISSC community is interested in Metocean Extremes which include extreme conditions (such as extreme tropical or extra-tropical cyclones), extreme events (such as rogue waves) and extreme environments (such as Marginal Ice Zone, MIZ). Certain Metocean conditions appear extreme, depending on applications (e.g.
- Europe > United Kingdom > England (1.00)
- Asia > Middle East > Saudi Arabia (1.00)
- Asia > Japan (1.00)
- (16 more...)
- Summary/Review (1.00)
- Research Report > New Finding (1.00)
- Research Report > Experimental Study (1.00)
- (3 more...)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Sedimentary Geology > Depositional Environment (0.67)
- Geophysics > Electromagnetic Surveying (0.65)
- Geophysics > Seismic Surveying > Seismic Modeling (0.45)
- Transportation > Passenger (1.00)
- Transportation > Marine (1.00)
- Transportation > Infrastructure & Services (1.00)
- (36 more...)
- Europe > Denmark > North Sea > Danish Sector > Central Graben > Block 5504/12 > Tyra Field (0.99)
- Europe > Denmark > North Sea > Danish Sector > Central Graben > Block 5504/11 > Tyra Field (0.99)
- North America > United States > Colorado > Ice Field (0.98)
- (18 more...)
- Well Drilling > Well Planning > Trajectory design (1.00)
- Well Drilling > Drillstring Design > Drill pipe selection (1.00)
- Well Drilling > Drilling Operations (1.00)
- (53 more...)
ABSTRACT The composite bucket shallow foundation that is proposed by Tianjin University can be better adapted to the offshore soft geological conditions in China for wind power engineering. Wind loading that directly determines the power generation efficiency of wind turbines, waves, currents and ice loading caused by a complex environment directly determines the horizontal displacement of the foundation. Therefore, calculating the horizontal bearing capacity is an important part of the design for the composite bucket shallow foundation. According to the numerical simulation, the failure surface of the soil is formed from the bottom of the rear wall of the bucket foundation, underneath the bucket foundation, to the front of the bucket foundation. Considering the different degrees of bucket foundation constraints on the inner soil, the horizontal soil damage rate is specified as a new empirical parameter in the formula, indicating the range of soil failure inside the bucket under horizontal loading. Upper bound solution of the horizontal bearing capacity of a composite bucket shallow foundation is derived in sand. INTRODUCTION Wind, as renewable clean energy, will become the new mainstay for the development of the world's energy. Wind power generation is one of the primary methods for wind power utilization. The investment of a wind power foundation is a major part of the offshore wind power budget(Lian et al., 2011; Le et al., 2014). Wind loading acting on the wind turbine directly determines the power generation efficiency of wind turbines. Therefore, horizontal wind loading is the primary loading in the design of offshore wind power foundations. Compared with onshore wind power foundations, offshore wind power foundations not only withstand huge wind loading but also bear waves, currents and ice loading caused by a complex environment. The combined effects of the above-mentioned horizontal loading will directly determine the horizontal displacement of the foundation. Therefore, calculating the horizontal load of offshore wind power foundations is an important consideration for the design of of ofshore wind power foundations.
- North America > United States (0.46)
- Asia > China > Tianjin Province > Tianjin (0.26)
- Health, Safety, Environment & Sustainability > Sustainability/Social Responsibility > Sustainable development (1.00)
- Health, Safety, Environment & Sustainability > Environment (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (1.00)
ABSTRACT Due to the lateral stiffness shortage of the monopile, and in order to improve the applicability of the monopile, a new wind turbine foundation type which is combining the jacket and monopile foundations is proposed. Based on the engineering example of offshore wind farm in Fujian Province, China, the main design parameters are considered. A 5 MW wind turbine foundation finite element model is established as the research object. Compared the results of monopile and the new composite foundation, conclusions are obtained. These findings will provide some reference for the new type foundation design. INTRODUCTION In recent years, the Chinese government on the development of clean energy, especially wind power gives a great policy support. China's wind power sector gained momentum due to the government's supportive policies. Sea wind is a permanent source which is inexhaustible and green new energy. Compared with onshore wind power, offshore wind power has many advantages, such as small land occupation, large wind speed, stable wind direction and little influence from surrounding buildings, etc.(Karadeniz et al., 2009) Commonly offshore wind turbine foundation type has gravity foundation, monopile foundation, tripod foundation, jacket foundation, floating foundation, suction caisson foundation and other types.(Westgate and DeJong, 2005) Monopile foundation as the most simple foundation structure is currently the most used wind turbines foundations for onshore and offshore wind farms.(Zaaijer, 2006) Its main advantages are the simplicity of design and manufacture, easy installation, and low costs.(Achmus et al., 2009) However, with the increase of water depth, the lateral rigidity of monopile becomes insufficient, and it can only be used for water depth within 30 m. Jacket foundation as another foundation for offshore wind turbines is more firm and stable than monopile foundation. It is suitable for 20 ~ 50 m water depth, but the costs for manufacture and installation are higher. (Jonkman et al., 2009)
- North America > United States (0.93)
- Asia > China > Fujian Province (0.25)
- Health, Safety, Environment & Sustainability > Sustainability/Social Responsibility > Sustainable development (1.00)
- Health, Safety, Environment & Sustainability > Environment (1.00)
Fundamental Structural Frequency Analysis For Jacket-Type OffshoreWind Turbine
Zhang, Min (Department of Ocean Engineering, Ocean University of China) | Li, Huajun (Department of Ocean Engineering, Ocean University of China) | Li, Ping (Department of Ocean Engineering, Ocean University of China) | Hu, S.-L. James (Department of Ocean Engineering, University of Rhode Island, Narragansett)
ABSTRACT In order to ensure safe designs for jacket-type offshore wind turbines (OWTs), the fundamental frequencies of the OWTs must avoid the aerodynamic frequencies caused by the operation of wind turbine and the hydrodynamic frequencies originated from sea waves. A jacket-type offshore wind turbine consists of three major components: rotor-nacelle assembly (RNA), tower and jacket-substructure (including foundation). The objective of this paper is to gain quantitative knowledge about the fundamental frequencies of the jacket-type OWTs under various combinations of these three components based on simplified models for OWTs. INTRODUCTION Offshore wind turbines (OWTs) are becoming more and more popular in the quest for renewable sources of energy. While the offshore wind technologies have been developed rapidly over the past 2 decades mainly in Europe, other regions in the world are currently also exploring their potential of offshore wind energy [Westgate and DeJong, 2005, Zaaijer, 2006]. As a consensus within the OWT industry, monopiles are the preferred solution for the support structures of OWTs in water depths up to 20–25 meters [Schaumann and B¨oker, 2005], but alternative support structures must be pursued for deeper water locations. Installing monopile structures in water depths more than 20–25 meters might require monopiles with the diameter exceeding the limitation imposed by the modern technologies and/or construction equipments. Experiences from the offshore oil and gas industry have led to the application of braced or lattice support structures for OWTs. Jacket-type substructures, which are lighter and stiffer in comparison to sufficiently designed monopiles, are attractive solutions in water depths of about 20 to 50 meters. As a jacket-type substructure provides the required structural stiffness through extending the base of the support, it also has advantages for the global load transmission in weak soils [Schaumann and B¨oker, 2005].
- Europe (1.00)
- Asia > China (0.47)
- North America > United States > Rhode Island (0.28)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (0.77)
- Data Science & Engineering Analytics > Information Management and Systems (0.69)
- Health, Safety, Environment & Sustainability > Sustainability/Social Responsibility > Sustainable development (0.68)
- Health, Safety, Environment & Sustainability > Environment (0.68)