海上风机基础在风浪作用下的动力分析与疲劳分析
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摘要
风能是一种清洁、安全、永续的可再生能源。相对于陆上风电,海上风电资源更丰富,前景更为广阔,但同时也处于更为复杂的海洋环境之中,海上风机基础结构在各种环境荷载(如风、波浪、海流等)作用下的安全性与稳定性,一直是研究领域中的重点与难点。因此,开展风机基础结构在主要环境荷载作用下的动力分析与疲劳分析对风机在服役期内的安全与使用有着非常重要的意义。
根据海床地质条件,选择三脚架桩式基础进行分析,主要研究内容包括：
1)对主要环境荷载进行分析计算。采用五阶Stokes波理论与Morison方程计算波流共同作用下斜桩与竖桩的波流荷载；对于动力分析,采用P-M波浪谱确定波面运动过程,进而确定波流荷载时程；根据风的特性采用滤波法模拟不同高度处的风荷载时程。
2)采用有限元分析软件ANSYS,建立支撑结构有限元模型,分别计算支撑结构在正常工况与极端工况时风、浪荷载作用下的动力响应,根据计算结果,确定结构承受的主导荷载,并以随机主导荷载叠加最大次要荷载的荷载组合方式组合风浪荷载,计算耦合荷载作用下结构的动力响应。结果表明,风机荷载为主导荷载,正常工况较极端风况结构响应更大,耦合荷载作用下支撑结构的响应主要反映了主导荷载—风荷载的随机特性。
3)采用基于S-N曲线和线性累积损伤准则的疲劳计算方法,对海上风机基础应力集中显著的关键位置的疲劳损伤进行了计算。采用广泛使用的热点应力法计算应力幅值,根据S-N曲线与疲劳设计因子计算出结构的疲劳损伤。
分别计算了结构在风机荷载与波浪荷载作用下的疲劳损伤度,再对二者进行叠加,进而求得结构位置在两种荷载作用下的疲劳损伤度。
Wind is a renewable energy which is clean, safe and permanent. Comparing to the land wind power, the offshore wind power has a more abundant resource and a vaster future. Meanwhile, the offshore wind turbine structures face a more complex ocean environment. They suffer kinds of stochastic loads which changes with time and space, such as wind, wave and current and so on. Therefore, the safety and stability of the structures under those loads are the difficulty and emphasis points.. So, it is so important to research the dynamical analysis under main environment loads and the fatigue analysis for the safety and operation in the service period.
According to the geological conditions of seabed at the site, the Tripod-Foundation is chosen for the wind farm. The paper mainly emphases on the following contents:
1) The main environment loads are calculated. It is used the nonlinear Stokes5wave theory and Morison equation for wave load. Time history curve of wave load is got by changing from P-M wave spectrum. Time history curve of wind load at different elevation is got by filter method.
2) Build support structure finite-element model in ANSYS, The dynamical analysis under wave and wind loads was made for the extreme and normal working conditions. We can ensure the main loads from results, then the coupling loads of stochastic mian loads with maximum miner loads are applied to analyze the dynamical responses of support structure for the extreme and normal states. The results show that the responses of structure for the normal state is bigger than that for the extreme state, and the response results mainly present the traits of wind load.
3) The method of S-N curve and Linear accumulative damage method are employed to calculate the fatigue damage for the place of stress concentration by hot pot stress method.
Fatigue damage under wind fatigue load and wave fatigue load is calculated respectively, and overplayed by damage coupling method, then got the total fatigue damage.
根据海床地质条件,选择三脚架桩式基础进行分析,主要研究内容包括：
1)对主要环境荷载进行分析计算。采用五阶Stokes波理论与Morison方程计算波流共同作用下斜桩与竖桩的波流荷载；对于动力分析,采用P-M波浪谱确定波面运动过程,进而确定波流荷载时程；根据风的特性采用滤波法模拟不同高度处的风荷载时程。
2)采用有限元分析软件ANSYS,建立支撑结构有限元模型,分别计算支撑结构在正常工况与极端工况时风、浪荷载作用下的动力响应,根据计算结果,确定结构承受的主导荷载,并以随机主导荷载叠加最大次要荷载的荷载组合方式组合风浪荷载,计算耦合荷载作用下结构的动力响应。结果表明,风机荷载为主导荷载,正常工况较极端风况结构响应更大,耦合荷载作用下支撑结构的响应主要反映了主导荷载—风荷载的随机特性。
3)采用基于S-N曲线和线性累积损伤准则的疲劳计算方法,对海上风机基础应力集中显著的关键位置的疲劳损伤进行了计算。采用广泛使用的热点应力法计算应力幅值,根据S-N曲线与疲劳设计因子计算出结构的疲劳损伤。
分别计算了结构在风机荷载与波浪荷载作用下的疲劳损伤度,再对二者进行叠加,进而求得结构位置在两种荷载作用下的疲劳损伤度。
Wind is a renewable energy which is clean, safe and permanent. Comparing to the land wind power, the offshore wind power has a more abundant resource and a vaster future. Meanwhile, the offshore wind turbine structures face a more complex ocean environment. They suffer kinds of stochastic loads which changes with time and space, such as wind, wave and current and so on. Therefore, the safety and stability of the structures under those loads are the difficulty and emphasis points.. So, it is so important to research the dynamical analysis under main environment loads and the fatigue analysis for the safety and operation in the service period.
According to the geological conditions of seabed at the site, the Tripod-Foundation is chosen for the wind farm. The paper mainly emphases on the following contents:
1) The main environment loads are calculated. It is used the nonlinear Stokes5wave theory and Morison equation for wave load. Time history curve of wave load is got by changing from P-M wave spectrum. Time history curve of wind load at different elevation is got by filter method.
2) Build support structure finite-element model in ANSYS, The dynamical analysis under wave and wind loads was made for the extreme and normal working conditions. We can ensure the main loads from results, then the coupling loads of stochastic mian loads with maximum miner loads are applied to analyze the dynamical responses of support structure for the extreme and normal states. The results show that the responses of structure for the normal state is bigger than that for the extreme state, and the response results mainly present the traits of wind load.
3) The method of S-N curve and Linear accumulative damage method are employed to calculate the fatigue damage for the place of stress concentration by hot pot stress method.
Fatigue damage under wind fatigue load and wave fatigue load is calculated respectively, and overplayed by damage coupling method, then got the total fatigue damage.
引文
[1]Global Wind Report Annual Market Update 2011 GEWC
[2]风光无限-中国风电发展报告2011.中国环境科学出版社,2011.6.
[3]宋础,刘汉中.海上风力发电场开发现状及发展趋势[J],太阳能,2006(2),p26-28
[4]邱大洪,薛鸿超.工程水文学(港口航道及海岸工程专业用)[M].北京：人民交通出版社,2004
[5]Sanjeev Malhotra, PE, GE(2009), Selection, Design and Construction of Offshore Wind Turbine Foundations, Wind Turbines, USA
[6]Bazeos, Hatzigeorgiou, Hondros Karamaneas H, Karabalis.seismic and stability analysis of a prototype wind turbine steel tower[J]. Eng Strct 2002;24:1015-25
[7]刘志强.海上风力发电支撑体系在环境荷载作用下动力响应分析[D].大连：大连理工大学,土木水利学院,2009.
[8]Berge B, Penzien J. Three-dimensional stochastic response of offshore towers to wave forces[C].the 6th Annual offshore Technology Conference, Houston:1974:173-190.
[9]王湘明,陈亮等.海上风力发电机组塔架海波荷载的分析[J].沈阳工业大学学报,2008,30(1)：42-45.
[10]Jan Van Der Tempel. Design of Support Structures for Offshore Wind Turbines[J],Offshore Engineering,Report,2006,OE.009.
[11]张蓓文,陆斌.欧洲海上风电场建设[J],上海电力,2007(2),p129-135
[12]莫为泽,冯宾春,邓杰.海上风电机组安装概述[J],水利水电技术,2009(9),p4-7
[13]张蓓文,HornsRev海上风电场探析[J],华东电力,2006(6),p86-89
[14]杨锋,邢占清,符平等.近海风机基础结构型式研究[J].水利水电技术,2009(9)：35-39.
[15]吴志良,王凤武.海上风电场风机基础型式及计算方法[J].水运工程,2008(10)：249-258.
[16]李静,孙亚胜.海上风力发电机组的基础形式[J].上海电力,2008(3)
[17]阮胜福.海上风电浮式基础动力响应研究[D].天津：天津大学建筑工程学院,2010.6.
[18]邓文旭.结构的脉动风荷载模拟方法探讨[J].安徽建筑,2007(4)
[19]刘锡良,周颖.风荷载的几种模拟方法[J].工业建筑,2005(5)
[20]楼文娟,孙炳楠.风与结构的耦合作用及风振响应分析[J].工程力学,2000(5)
[21]孙振.建筑结构风荷载的计算机模拟与分析[D].南京：南京航空航天大学,航空宇航学院,2007.
[22]李春祥,都敏,韩兵康.基于AR模型模拟超高层建筑的脉动风速时程[J].地震工程与工程振动,2008,28(3)
[23]李玉成,滕斌.波浪对海上建筑物的作用[M].北京：海洋出版社,2002
[24]刘英杰,自升式平台桩腿的受力分析[D].哈尔滨：哈尔滨工程大学,2004
[25]邹志利.水波理论及其应用[M].北京：科学出版社,2005
[26]竺艳蓉.海洋工程波浪力学.天津：天津大学出版社,1991
[27]俞聿修.随机波浪及其工程应用[M].大连：大连理工大学出版社,2003
[28]李晔,李红涛.海上风机支撑结构设计分析研究[A].第十三届中国科协会第十三分场-海洋工程装备发展论坛论文集[C].2011
[29]张宗峰,冯春健.基于ANSYS的单立柱海洋平台动力特性分析[A].第六届全国现代结构工程学术研讨会论文集[C].2006
[30]陈为飞.近海风机塔架风浪荷载分析[D].杭州：浙江大学建筑工程学院,2007.
[31]蔡安民.近海风力机风波联合作用下的荷载分析研究[D].汕头：汕头大学机械电子工程学院,2007.
[32]Wolfgang Fricke. Fatigue analysis of welded joints:state of development [J]. Marine Structures. 2003(16),P185-200
[33]周张义,李芾,黄运华.基于热点应力的焊缝疲劳强度评定研究[J].内燃机车,2008(7)
[34]DNV-OS-J101,Design of offshore wind turbine structure[M].2007
[35]Holger Huhn, Stefan Herion. Solution of Fatigue Problems for Support Structures of Offshore Wind Energy Converters[A]. Proceedings of the 16th International Offshore and Polar Engineering Conference[C].ISOPE-2006,San Francisco:P383-388.
[36]李红涛,李林斌.海上风机支撑结构设计分析[J],海洋工程,2011,29(4),p74-80
[37]Fugro-GEOS, Metocean Criteria for the Blyth Offshore Wind Form[R].1999
[38]Ferguson, MC, A Typical Design Solution for an Offshore Wind Energy Conversion System[R] Opti-OWECS Final report, Vol(4),1998.
[39]张淑茳,史冬岩.海洋工程结构的疲劳与断裂[M].哈尔滨：哈尔滨工程大学出版社,2005
[40]王浚璞,艾志久,李旭志等.基于SACS的海洋平台疲劳可靠度分析[J],石油矿场机械,2008,37(9),p24-27
[41]欧进萍,王光远.结构随机振动[M].北京：高等教育出版社,1998
[2]风光无限-中国风电发展报告2011.中国环境科学出版社,2011.6.
[3]宋础,刘汉中.海上风力发电场开发现状及发展趋势[J],太阳能,2006(2),p26-28
[4]邱大洪,薛鸿超.工程水文学(港口航道及海岸工程专业用)[M].北京：人民交通出版社,2004
[5]Sanjeev Malhotra, PE, GE(2009), Selection, Design and Construction of Offshore Wind Turbine Foundations, Wind Turbines, USA
[6]Bazeos, Hatzigeorgiou, Hondros Karamaneas H, Karabalis.seismic and stability analysis of a prototype wind turbine steel tower[J]. Eng Strct 2002;24:1015-25
[7]刘志强.海上风力发电支撑体系在环境荷载作用下动力响应分析[D].大连：大连理工大学,土木水利学院,2009.
[8]Berge B, Penzien J. Three-dimensional stochastic response of offshore towers to wave forces[C].the 6th Annual offshore Technology Conference, Houston:1974:173-190.
[9]王湘明,陈亮等.海上风力发电机组塔架海波荷载的分析[J].沈阳工业大学学报,2008,30(1)：42-45.
[10]Jan Van Der Tempel. Design of Support Structures for Offshore Wind Turbines[J],Offshore Engineering,Report,2006,OE.009.
[11]张蓓文,陆斌.欧洲海上风电场建设[J],上海电力,2007(2),p129-135
[12]莫为泽,冯宾春,邓杰.海上风电机组安装概述[J],水利水电技术,2009(9),p4-7
[13]张蓓文,HornsRev海上风电场探析[J],华东电力,2006(6),p86-89
[14]杨锋,邢占清,符平等.近海风机基础结构型式研究[J].水利水电技术,2009(9)：35-39.
[15]吴志良,王凤武.海上风电场风机基础型式及计算方法[J].水运工程,2008(10)：249-258.
[16]李静,孙亚胜.海上风力发电机组的基础形式[J].上海电力,2008(3)
[17]阮胜福.海上风电浮式基础动力响应研究[D].天津：天津大学建筑工程学院,2010.6.
[18]邓文旭.结构的脉动风荷载模拟方法探讨[J].安徽建筑,2007(4)
[19]刘锡良,周颖.风荷载的几种模拟方法[J].工业建筑,2005(5)
[20]楼文娟,孙炳楠.风与结构的耦合作用及风振响应分析[J].工程力学,2000(5)
[21]孙振.建筑结构风荷载的计算机模拟与分析[D].南京：南京航空航天大学,航空宇航学院,2007.
[22]李春祥,都敏,韩兵康.基于AR模型模拟超高层建筑的脉动风速时程[J].地震工程与工程振动,2008,28(3)
[23]李玉成,滕斌.波浪对海上建筑物的作用[M].北京：海洋出版社,2002
[24]刘英杰,自升式平台桩腿的受力分析[D].哈尔滨：哈尔滨工程大学,2004
[25]邹志利.水波理论及其应用[M].北京：科学出版社,2005
[26]竺艳蓉.海洋工程波浪力学.天津：天津大学出版社,1991
[27]俞聿修.随机波浪及其工程应用[M].大连：大连理工大学出版社,2003
[28]李晔,李红涛.海上风机支撑结构设计分析研究[A].第十三届中国科协会第十三分场-海洋工程装备发展论坛论文集[C].2011
[29]张宗峰,冯春健.基于ANSYS的单立柱海洋平台动力特性分析[A].第六届全国现代结构工程学术研讨会论文集[C].2006
[30]陈为飞.近海风机塔架风浪荷载分析[D].杭州：浙江大学建筑工程学院,2007.
[31]蔡安民.近海风力机风波联合作用下的荷载分析研究[D].汕头：汕头大学机械电子工程学院,2007.
[32]Wolfgang Fricke. Fatigue analysis of welded joints:state of development [J]. Marine Structures. 2003(16),P185-200
[33]周张义,李芾,黄运华.基于热点应力的焊缝疲劳强度评定研究[J].内燃机车,2008(7)
[34]DNV-OS-J101,Design of offshore wind turbine structure[M].2007
[35]Holger Huhn, Stefan Herion. Solution of Fatigue Problems for Support Structures of Offshore Wind Energy Converters[A]. Proceedings of the 16th International Offshore and Polar Engineering Conference[C].ISOPE-2006,San Francisco:P383-388.
[36]李红涛,李林斌.海上风机支撑结构设计分析[J],海洋工程,2011,29(4),p74-80
[37]Fugro-GEOS, Metocean Criteria for the Blyth Offshore Wind Form[R].1999
[38]Ferguson, MC, A Typical Design Solution for an Offshore Wind Energy Conversion System[R] Opti-OWECS Final report, Vol(4),1998.
[39]张淑茳,史冬岩.海洋工程结构的疲劳与断裂[M].哈尔滨：哈尔滨工程大学出版社,2005
[40]王浚璞,艾志久,李旭志等.基于SACS的海洋平台疲劳可靠度分析[J],石油矿场机械,2008,37(9),p24-27
[41]欧进萍,王光远.结构随机振动[M].北京：高等教育出版社,1998