Tension leg platform （TLP） for offshore wind turbine support is a new type structure in wind energy utilization. The strong-interaction method is used in analyzing the coupled model, and the dynamic characteristics ...Tension leg platform （TLP） for offshore wind turbine support is a new type structure in wind energy utilization. The strong-interaction method is used in analyzing the coupled model, and the dynamic characteristics of the TLP for offshore wind turbine support are recognized. As shown by the calculated results： for the lower modes, the shapes are water＇s vibration, and the vibration of water induces the structure＇s swing; the mode shapes of the structure are complex, and can largely change among different members; the mode shapes of the platform are related to the tower＇s. The frequencies of the structure do not change much after adjusting the length of the tension cables and the depth of the platform; the TLP has good adaptability for the water depths and the environment loads. The change of the size and parameters of TLP can improve the dynamic characteristics, which can reduce the vibration of the TLP caused by the loads. Through the vibration analysis, the natural vibration frequencies of TLP can be distinguished from the frequencies of condition loads, and thus the resonance vibration can be avoided, therefore the offshore wind turbine can work normally in the complex conditions.展开更多
A new class of support structures, called Periodic Structures, is introduced in this paper as a viable means for isolating the vibration transmitted from the sea waves to offshore platform structures through its legs....A new class of support structures, called Periodic Structures, is introduced in this paper as a viable means for isolating the vibration transmitted from the sea waves to offshore platform structures through its legs. A passive approach to reduce transmitted vibration generated by waves is presented. The approach utilizes the property of periodic structural components that create stop and pass bands. The stop band regions can be tailored to correspond to regions of the frequency spectra that contain harmonics of the wave frequency, attenuating the response in those regions. A periodic structural component is comprised of a repeating array of cells, which are themselves an assembly of elements. The elements may have differing material properties as well as geometric variations. For the purpose of this research, only geometric and material variations are considered and each cell is assumed to be identical. A periodic leg is designed in order to reduce transmitted vibration of sea waves. The effectiveness of the periodicity on the vibration levels of platform will be demonstrated theoretically. The theory governing the operation of this class of periodic structures is introduced using the transfer matrix method. The unique filtering characteristics of periodic structures are demonstrated as functions of their design parameters for structures with geometrical and material discontinuities, and determine the propagation factor by using the spectral finite element analysis and the effectiveness of design on the leg structure by changing the ratio of step length and area interface between the materials is demonstrated in order to find the propagation factor and frequency response.展开更多
张力腿平台结构在外界环境载荷作用下的力学分析是张力腿平台设计研究的重点。利用ANSYS软件,采用拟静力分析的方法,对张力腿平台(Tension Leg Platform,TLP)在极端海况风、波、流载荷联合作用下的结构强度进行分析,并针对平台应力集中...张力腿平台结构在外界环境载荷作用下的力学分析是张力腿平台设计研究的重点。利用ANSYS软件,采用拟静力分析的方法,对张力腿平台(Tension Leg Platform,TLP)在极端海况风、波、流载荷联合作用下的结构强度进行分析,并针对平台应力集中区域通过添加支撑板的方法进行了局部改进,对改进后的平台再次进行了模拟验证。结果表明:平台立柱隔板的中央位置和立柱顶端变形量较大;平台顶部隔板、底部隔板与立柱联接的地方均出现应力集中;在平台应力集中区域添加支撑板的方法可以明显改善平台局部区域的应力分布,降低应力集中现象的危害。展开更多
文摘Tension leg platform （TLP） for offshore wind turbine support is a new type structure in wind energy utilization. The strong-interaction method is used in analyzing the coupled model, and the dynamic characteristics of the TLP for offshore wind turbine support are recognized. As shown by the calculated results： for the lower modes, the shapes are water＇s vibration, and the vibration of water induces the structure＇s swing; the mode shapes of the structure are complex, and can largely change among different members; the mode shapes of the platform are related to the tower＇s. The frequencies of the structure do not change much after adjusting the length of the tension cables and the depth of the platform; the TLP has good adaptability for the water depths and the environment loads. The change of the size and parameters of TLP can improve the dynamic characteristics, which can reduce the vibration of the TLP caused by the loads. Through the vibration analysis, the natural vibration frequencies of TLP can be distinguished from the frequencies of condition loads, and thus the resonance vibration can be avoided, therefore the offshore wind turbine can work normally in the complex conditions.
文摘A new class of support structures, called Periodic Structures, is introduced in this paper as a viable means for isolating the vibration transmitted from the sea waves to offshore platform structures through its legs. A passive approach to reduce transmitted vibration generated by waves is presented. The approach utilizes the property of periodic structural components that create stop and pass bands. The stop band regions can be tailored to correspond to regions of the frequency spectra that contain harmonics of the wave frequency, attenuating the response in those regions. A periodic structural component is comprised of a repeating array of cells, which are themselves an assembly of elements. The elements may have differing material properties as well as geometric variations. For the purpose of this research, only geometric and material variations are considered and each cell is assumed to be identical. A periodic leg is designed in order to reduce transmitted vibration of sea waves. The effectiveness of the periodicity on the vibration levels of platform will be demonstrated theoretically. The theory governing the operation of this class of periodic structures is introduced using the transfer matrix method. The unique filtering characteristics of periodic structures are demonstrated as functions of their design parameters for structures with geometrical and material discontinuities, and determine the propagation factor by using the spectral finite element analysis and the effectiveness of design on the leg structure by changing the ratio of step length and area interface between the materials is demonstrated in order to find the propagation factor and frequency response.
文摘张力腿平台结构在外界环境载荷作用下的力学分析是张力腿平台设计研究的重点。利用ANSYS软件,采用拟静力分析的方法,对张力腿平台(Tension Leg Platform,TLP)在极端海况风、波、流载荷联合作用下的结构强度进行分析,并针对平台应力集中区域通过添加支撑板的方法进行了局部改进,对改进后的平台再次进行了模拟验证。结果表明:平台立柱隔板的中央位置和立柱顶端变形量较大;平台顶部隔板、底部隔板与立柱联接的地方均出现应力集中;在平台应力集中区域添加支撑板的方法可以明显改善平台局部区域的应力分布,降低应力集中现象的危害。
