CAREER: Irregular Environmental Loading and Response of Offshore Structures

职业：海上结构的不规则环境载荷和响应

• 批准号: 0448730
• 负责人: John Sweetman
• 金额: $ 40万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0448730&HistoricalAwards=false
• 关键词: CAREER; Irregular; Environmental; Loading; Response

Abstract for: CAREER: Irregular Environmental Loading and Response of Offshore Structures, CMS proposal 0448730PI: Sweetman, Texas A&M - GalvestonRecent computer and sensor hardware developments have dramatically increased field datacollection capabilities, outpacing development of new methodologies to make optimal use ofthese data. Hydrodynamic loading and fluid-structure interaction on offshore structures havelong been targeted with computer-intensive deterministic calculations, but these processes areinherently stochastic, for which no adequate methodologies exist to quantify structural loads andresponse. Here, random process theory, structural dynamics, hydrodynamics, and measured data interpretation will be combined to improve design methods for offshore structures and enable verification of deterministic hydrodynamic theories with full-scale measured data. New methodologies and associated numerical tools for prediction of fluid-structure interaction in both shallow and very deep waters are proposed. Example applications will be worked in detail relevant to load and response predictions for offshore wind turbines and marine risers. Marine risers are the vertical pipes carrying fluids between the sea-floor and sea-surface. The PI's doctoral research at Stanford integrated fluid-structure interaction, random vibrations and extreme value theory and included extensive comparison with measured data. He also has ten years of industry experience in advanced methods for design and construction of offshore structures where he saw the need for new ways to quantify environmental load and response of offshore structures.Intellectual Merit: This research increases the fundamental understanding of fluid-structureinteraction in both shallow and very deep waters, develops new engineering methods, and applies these new methods to develop new numerical tools for use in design and test of hydrodynamic theories. The wind turbine work combines statistical methods and stream function wave theory with a new dynamic numerical model to better predict wave loading on the structure and to better understand the complicated interaction between winds, waves, and the structure. The marine riser work addresses vortex-induced vibration (VIV), a fluid-structure interaction problem dominating design of long marine risers in high currents. A new random vibration methodology will be developed where statistical distributions built from measured data are used to quantitatively assess the effectiveness of hydrodynamic theories. The new methodology may find use in various structural vibration applications.Specific research goals include: (1) develop a new irregular wave simulation methodologyto predict ocean wave profiles and kinematics based on stream function theory; (2) developa new random process model to combine the new irregular wave methodology with irregularwind characterizations to predict extreme loading on offshore wind turbines; (3) critically comparethe results from (1) and (2) with full-scale measured data to verify the new methods; (4)develop a deterministic dynamic model of a marine riser in very deep water; (5) develop statisticaldistributions of riser accelerations from measured data; (6) use results of (4) and (5) toquantitatively assess the likelihood that hypothesized hydrodynamic theories explain observedacceleration data; and (7) other applications of the new methodology.Broader Impact: The proposed work will have direct impact on future design of offshore windturbines and marine risers by providing a better understanding of complex interactions betweena structure and its environment. Both of these areas are relevant to present and future worldenergy supplies. The project will also enhance cross-pollination of ideas between two differenttechnical cultures: European-dominated offshore wind energy and the US-dominated deep-wateroffshore oil production.Specific educational and broader impact goals include: (1) development of a new course in off-shore and near-shore structural dynamics and fluid-structure interaction including some resultsfrom this research; (2) outreach to science and technology students from historically underrepresented and financially challenged situations through the NSF-funded "GATES" program; (3) outreach to K-12 students and educators through the existing Sea Camp Program, which has hosted over 10,000 K-12 students and 1,000 K-12 teachers at TAMUG to date, and (4) education of promising graduate students in important emerging technical areas.

摘要：职业生涯：不规则的环境载荷和响应的海洋结构，CMS建议0448730 PI：斯威特曼，得克萨斯州A M -加尔维斯顿最近的计算机和传感器硬件的发展大大增加了现场的采集能力，超过了新的方法，使这些数据的最佳利用的发展。海洋结构物上的水动力载荷和流体-结构相互作用一直是计算机密集型确定性计算的目标，但这些过程本质上是随机的，因此没有足够的方法来量化结构载荷和响应。在这里，随机过程理论，结构动力学，流体动力学和测量数据解释将结合起来，以改善海上结构的设计方法，并使确定性流体动力学理论与全尺寸测量数据的验证。提出了预测浅水和超深沃茨中流体-结构相互作用的新方法和相关数值工具。将详细介绍与海上风力涡轮机和船用涡轮机的负载和响应预测相关的示例应用。海底管道是海底与海面之间输送流体的垂直管道。PI在斯坦福大学的博士研究综合了流体-结构相互作用、随机振动和极值理论，并包括与测量数据的广泛比较。他还在海洋结构物的先进设计和施工方法方面拥有十年的行业经验，他认为需要新的方法来量化海洋结构物的环境载荷和响应。这项研究增加了对浅水和超深水沃茨中流体-结构相互作用的基本理解，开发了新的工程方法，并将这些新方法应用于开发新的数值工具，用于流体动力学理论的设计和检验。风力涡轮机工作将统计方法和流函数波浪理论与新的动态数值模型相结合，以更好地预测结构上的波浪载荷，并更好地理解风、波浪和结构之间的复杂相互作用。海洋立管的工作解决涡激振动（VIV），一个流体-结构相互作用的问题，主导设计的长海洋立管在高电流。将开发一种新的随机振动方法，根据测量数据建立的统计分布用于定量评估流体动力学理论的有效性。具体的研究目标包括：（1）发展一种新的基于流函数理论的不规则波模拟方法来预测海洋波浪剖面和运动学，（2）发展一种新的随机过程模型，将新的不规则波模拟方法与不规则风特性联合收割机结合起来预测海上风力发电机的极端载荷，（3）发展一种新的基于流函数理论的不规则波模拟方法来预测海上风力发电机的极端载荷，（4）发展一种新的随机过程模型来预测海上风力发电机的极端载荷。（3）将（1）和（2）的计算结果与实船实测数据进行比较，以验证新方法的正确性：（4）建立深水立管的确定性动力学模型：（5）根据实测数据建立立管加速度的纵向分布;（6）使用（4）和（5）的结果来定量评估假设的流体动力学理论解释加速数据的可能性;以及（7）新方法的其他应用。通过更好地理解结构与环境之间的复杂相互作用，拟议的工作将对未来海上风力涡轮机和海洋涡轮机的设计产生直接影响。这两个领域都与当今和未来的世界能源供应相关。该项目还将促进两种不同技术文化之间的思想交叉授粉：欧洲主导的海上风能和美国主导的深水近海石油生产。具体的教育和更广泛的影响目标包括：（1）开发一个新的课程，在近海和近岸结构动力学和流体-结构相互作用，包括本研究的一些结果;（2）通过NSF资助的“GATES”计划，向历史上代表性不足和经济困难的科学和技术学生进行宣传;（3）通过现有的海上营地计划与K-12学生和教育工作者进行外联，该计划迄今已在TAMUG接待了10，000多名K-12学生和1，000名K-12教师，（4）在重要的新兴技术领域培养有前途的研究生。