The Experts below are selected from a list of 1347 Experts worldwide ranked by ideXlab platform
Yuna Zhao - One of the best experts on this subject based on the ideXlab platform.
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Numerical study on the feasibility of offshore single blade installation by floating Crane Vessels
Marine Structures, 2019Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir MoanAbstract:Abstract Compared with jack-up Crane Vessels that are now widely used in offshore wind turbine installation, floating Crane Vessels are more flexible with respect to working water depth and are much faster in relocation. They are thus a promising alternative to install offshore wind turbine components, especially in intermediate and deep water. However, the wave-induced motions of the floating Vessels make the operations challenging. This study deals with a preliminary feasibility study on offshore single blade installation using floating Crane Vessels. Two typical floating Crane Vessels are considered, i.e., a mono-hull Vessel and a semi-submersible Vessel. They are assumed to be equipped with dynamic positioning systems that can well mitigate the slowly varying horizontal motions. Their overall performance during the blade installation is numerically evaluated by comparing their performance against a typical jack-up Crane Vessel. The Crane dynamics plays a less important role for blade installation by floating Vessels, compared to the jack-up Crane Vessel. The floating Vessels’ wave-induced motion greatly affects the blade motion. The semi-submersible Vessel causes a much smaller blade motion than the mono-hull Vessel. The results indicate that it is feasible to install offshore wind turbine blades by using floating Crane Vessels provided that the Vessel type is properly selected. From the operability point of view, semi-submersible Vessels are more feasible than mono-hull Vessels for offshore single blade installations.
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Explicit Structural Response-Based Methodology for Assessment of Operational Limits for Single Blade Installation for Offshore Wind Turbines
Lecture Notes in Civil Engineering, 2018Co-Authors: Amrit Shankar Verma, Yuna Zhao, Zhen Gao, Nils Petter VedvikAbstract:The growing requirements of large-sized offshore wind turbines require heavier components to be lifted to large heights using installation Vessels. This imposes a substantial risk of impact to the lifted components especially when floating Crane Vessels are used. Floating Crane Vessels are in general sensitive to wave-induced motion, causing substantial Crane tip responses and can lead to significant damage to the lifted blades. Currently, the planning for such weather sensitive operation does not include explicitly the risk of contact/impact or damage in the components to determine the operational limits. This is important for wind turbine blades owing to the fact that they are made of composite materials and are vulnerable to damage from contact/impact loads. The present paper proposes a novel methodology to determine response based operational limit for the blade installation by considering impact loads. Structural damage criteria for the lifted blade under accidental loads are linked with global response analysis of the installation system under stochastic wind and wave loads. A case study is also presented where a wind turbine blade lifted horizontally using jack-up Crane Vessel impacts the pre-assembled turbine tower with its tip region while being installed under mean wind speed of 10 m/s. It is found that under such conditions, it is safe to install blade from structural damage perspective as the characteristic responses obtained were low to develop any damage in the blade. The findings of the study can be used to derive limiting sea states for blade installation using floating Vessels, however a damage tolerance approach requiring residual strength analysis post impact is compulsory.
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Effect of Foundation Modeling of a Jack-Up Crane Vessel on the Dynamic Motion Response of an Offshore Wind Turbine Blade During Installation
ASME 2018 1st International Offshore Wind Technical Conference, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Zhen Gao, Torgeir MoanAbstract:Nowadays, there is an increasing demand for use of jack-up Crane Vessels to install offshore wind turbines. These Vessels usually have shallow soil penetration during offshore Crane operations because of the requirement of frequent repositioning. The soil-structure interaction should thus be properly modeled for evaluating the motion responses, especially at Crane tip at large lifting height. Excessive Crane tip motion affects the dynamic responses of the lifted components and subsequently affects the safety and efficiency of operations. The present study addresses the effects of soil behaviour modeling of a typical jack-up Crane Vessel on the dynamic motion responses of a wind turbine blade during installation using a fully coupled method. The coupled method account for wind loads on the blade and the Vessel hull, wave loads on the Vessel legs, soil-structure interaction, structural flexibility of the Vessel legs and Crane, and the mechanical wire couplings. Three models for the soil-leg interactions and two soil types are considered. The foundation modeling is found to have vital effects on the system dynamic motion responses. The characteristics of system motion differ under different types of soil. Compared to the combined linear spring and damper model, the simplified pinned and fixed foundations respectively lead to significant overestimation and underestimation of the motion responses of the blade during installation by jack-up Crane Vessels. To ensure safe and efficient offshore operations, detailed site specific soil properties should be used in numerical studies of offshore Crane operations using jack-up Crane Vessels.
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Numerical modeling and analysis of the dynamic motion response of an offshore wind turbine blade during installation by a jack-up Crane Vessel
Ocean Engineering, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir Moan, Eric Van BurenAbstract:Abstract Jack-up Crane Vessels are commonly used to install offshore wind turbine blades and other components. A jack-up Crane Vessel is subjected to wind and wave loads, which cause motion at Crane tip. Excessive motion at Crane tip can lead to failure of lifting operations. Therefore, the Crane tip motion should be properly assessed for jack-up Crane Vessels. In this study, a fully coupled model is developed for a typical elevated jack-up Crane Vessel, considering the hydrodynamic and aerodynamic loads on the Vessel, the soil-structure interaction, and the structural flexibility of the jack-up legs and Crane. The Vessel model developed is further coupled with the SIMO-Aero code to achieve a fully coupled aero-hydro-soil-elastic-mechanical code SIMO-RIFLEX-Aero for numerical modeling and dynamic analysis of offshore single blade installation using jack-up Crane Vessels. The SIMO-RIFLEX-Aero code is then applied to study the dynamic response of the DTU 10 MW wind turbine blade installed by a typical jack-up Crane Vessel under various wind and wave conditions. The results show that significant motion is induced at Crane tip, mainly due to wave loads. It is important to consider the structural flexibility of the jack-up legs and Crane when modeling the installation of offshore wind turbine blades.
Torgeir Moan - One of the best experts on this subject based on the ideXlab platform.
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Numerical study on the feasibility of offshore single blade installation by floating Crane Vessels
Marine Structures, 2019Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir MoanAbstract:Abstract Compared with jack-up Crane Vessels that are now widely used in offshore wind turbine installation, floating Crane Vessels are more flexible with respect to working water depth and are much faster in relocation. They are thus a promising alternative to install offshore wind turbine components, especially in intermediate and deep water. However, the wave-induced motions of the floating Vessels make the operations challenging. This study deals with a preliminary feasibility study on offshore single blade installation using floating Crane Vessels. Two typical floating Crane Vessels are considered, i.e., a mono-hull Vessel and a semi-submersible Vessel. They are assumed to be equipped with dynamic positioning systems that can well mitigate the slowly varying horizontal motions. Their overall performance during the blade installation is numerically evaluated by comparing their performance against a typical jack-up Crane Vessel. The Crane dynamics plays a less important role for blade installation by floating Vessels, compared to the jack-up Crane Vessel. The floating Vessels’ wave-induced motion greatly affects the blade motion. The semi-submersible Vessel causes a much smaller blade motion than the mono-hull Vessel. The results indicate that it is feasible to install offshore wind turbine blades by using floating Crane Vessels provided that the Vessel type is properly selected. From the operability point of view, semi-submersible Vessels are more feasible than mono-hull Vessels for offshore single blade installations.
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Effect of Foundation Modeling of a Jack-Up Crane Vessel on the Dynamic Motion Response of an Offshore Wind Turbine Blade During Installation
ASME 2018 1st International Offshore Wind Technical Conference, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Zhen Gao, Torgeir MoanAbstract:Nowadays, there is an increasing demand for use of jack-up Crane Vessels to install offshore wind turbines. These Vessels usually have shallow soil penetration during offshore Crane operations because of the requirement of frequent repositioning. The soil-structure interaction should thus be properly modeled for evaluating the motion responses, especially at Crane tip at large lifting height. Excessive Crane tip motion affects the dynamic responses of the lifted components and subsequently affects the safety and efficiency of operations. The present study addresses the effects of soil behaviour modeling of a typical jack-up Crane Vessel on the dynamic motion responses of a wind turbine blade during installation using a fully coupled method. The coupled method account for wind loads on the blade and the Vessel hull, wave loads on the Vessel legs, soil-structure interaction, structural flexibility of the Vessel legs and Crane, and the mechanical wire couplings. Three models for the soil-leg interactions and two soil types are considered. The foundation modeling is found to have vital effects on the system dynamic motion responses. The characteristics of system motion differ under different types of soil. Compared to the combined linear spring and damper model, the simplified pinned and fixed foundations respectively lead to significant overestimation and underestimation of the motion responses of the blade during installation by jack-up Crane Vessels. To ensure safe and efficient offshore operations, detailed site specific soil properties should be used in numerical studies of offshore Crane operations using jack-up Crane Vessels.
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Numerical modeling and analysis of the dynamic motion response of an offshore wind turbine blade during installation by a jack-up Crane Vessel
Ocean Engineering, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir Moan, Eric Van BurenAbstract:Abstract Jack-up Crane Vessels are commonly used to install offshore wind turbine blades and other components. A jack-up Crane Vessel is subjected to wind and wave loads, which cause motion at Crane tip. Excessive motion at Crane tip can lead to failure of lifting operations. Therefore, the Crane tip motion should be properly assessed for jack-up Crane Vessels. In this study, a fully coupled model is developed for a typical elevated jack-up Crane Vessel, considering the hydrodynamic and aerodynamic loads on the Vessel, the soil-structure interaction, and the structural flexibility of the jack-up legs and Crane. The Vessel model developed is further coupled with the SIMO-Aero code to achieve a fully coupled aero-hydro-soil-elastic-mechanical code SIMO-RIFLEX-Aero for numerical modeling and dynamic analysis of offshore single blade installation using jack-up Crane Vessels. The SIMO-RIFLEX-Aero code is then applied to study the dynamic response of the DTU 10 MW wind turbine blade installed by a typical jack-up Crane Vessel under various wind and wave conditions. The results show that significant motion is induced at Crane tip, mainly due to wave loads. It is important to consider the structural flexibility of the jack-up legs and Crane when modeling the installation of offshore wind turbine blades.
Zhen Gao - One of the best experts on this subject based on the ideXlab platform.
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Numerical study on the feasibility of offshore single blade installation by floating Crane Vessels
Marine Structures, 2019Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir MoanAbstract:Abstract Compared with jack-up Crane Vessels that are now widely used in offshore wind turbine installation, floating Crane Vessels are more flexible with respect to working water depth and are much faster in relocation. They are thus a promising alternative to install offshore wind turbine components, especially in intermediate and deep water. However, the wave-induced motions of the floating Vessels make the operations challenging. This study deals with a preliminary feasibility study on offshore single blade installation using floating Crane Vessels. Two typical floating Crane Vessels are considered, i.e., a mono-hull Vessel and a semi-submersible Vessel. They are assumed to be equipped with dynamic positioning systems that can well mitigate the slowly varying horizontal motions. Their overall performance during the blade installation is numerically evaluated by comparing their performance against a typical jack-up Crane Vessel. The Crane dynamics plays a less important role for blade installation by floating Vessels, compared to the jack-up Crane Vessel. The floating Vessels’ wave-induced motion greatly affects the blade motion. The semi-submersible Vessel causes a much smaller blade motion than the mono-hull Vessel. The results indicate that it is feasible to install offshore wind turbine blades by using floating Crane Vessels provided that the Vessel type is properly selected. From the operability point of view, semi-submersible Vessels are more feasible than mono-hull Vessels for offshore single blade installations.
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Response-Based Assessment of Operational Limits for Mating Blades on Monopile-Type Offshore Wind Turbines
MDPI AG, 2019Co-Authors: Amrit Shankar Verma, Zhen Gao, Zhiyu Jiang, Zhengru Ren, Nils Petter VedvikAbstract:Installation of wind-turbine blades on monopile-type offshore wind turbines is a demanding task. Typically, a jack-up Crane Vessel is used, and blades are individually lifted from the Vessel deck and docked with the preinstalled hub. During the process of mating, large relative motions are developed between the hub and root due to combined effects of wind-generated blade-root responses and wave-generated monopile vibrations. This can cause impact loads at the blade root and induce severe damages at the blade-root connection. Such events are highly likely to cause the failure of the mating task, while affecting the subsequent activities, and thus require competent planning. The purpose of this paper is to present a probabilistic response-based methodology for estimating the allowable sea states for planning a wind-turbine blade-mating task, considering impact risks with the hub as the hazardous event. A case study is presented where the installation system consisting of blade-lift and monopile system are modelled using multibody formulations. Time-domain analyses are carried out for various sea states, and impact velocities between root and hub are analyzed. Finally, an extreme value analysis using the Gumbel fitting of response parameters is performed and limiting sea state curves are obtained by comparing characteristic extreme responses with allowable values. It is found that the limiting sea states for blade-root mating tasks are low for aligned wind–wave conditions, and further increase with increased wind–wave misalignment. The results of the study also show that the parameter T p is essential for estimating limiting sea states given that this parameter significantly influences monopile vibrations during the blade-root mating task. Overall, the findings of the study can be used for a safer and more cost-effective mating of wind-turbine blades
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Explicit Structural Response-Based Methodology for Assessment of Operational Limits for Single Blade Installation for Offshore Wind Turbines
Lecture Notes in Civil Engineering, 2018Co-Authors: Amrit Shankar Verma, Yuna Zhao, Zhen Gao, Nils Petter VedvikAbstract:The growing requirements of large-sized offshore wind turbines require heavier components to be lifted to large heights using installation Vessels. This imposes a substantial risk of impact to the lifted components especially when floating Crane Vessels are used. Floating Crane Vessels are in general sensitive to wave-induced motion, causing substantial Crane tip responses and can lead to significant damage to the lifted blades. Currently, the planning for such weather sensitive operation does not include explicitly the risk of contact/impact or damage in the components to determine the operational limits. This is important for wind turbine blades owing to the fact that they are made of composite materials and are vulnerable to damage from contact/impact loads. The present paper proposes a novel methodology to determine response based operational limit for the blade installation by considering impact loads. Structural damage criteria for the lifted blade under accidental loads are linked with global response analysis of the installation system under stochastic wind and wave loads. A case study is also presented where a wind turbine blade lifted horizontally using jack-up Crane Vessel impacts the pre-assembled turbine tower with its tip region while being installed under mean wind speed of 10 m/s. It is found that under such conditions, it is safe to install blade from structural damage perspective as the characteristic responses obtained were low to develop any damage in the blade. The findings of the study can be used to derive limiting sea states for blade installation using floating Vessels, however a damage tolerance approach requiring residual strength analysis post impact is compulsory.
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Effect of Foundation Modeling of a Jack-Up Crane Vessel on the Dynamic Motion Response of an Offshore Wind Turbine Blade During Installation
ASME 2018 1st International Offshore Wind Technical Conference, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Zhen Gao, Torgeir MoanAbstract:Nowadays, there is an increasing demand for use of jack-up Crane Vessels to install offshore wind turbines. These Vessels usually have shallow soil penetration during offshore Crane operations because of the requirement of frequent repositioning. The soil-structure interaction should thus be properly modeled for evaluating the motion responses, especially at Crane tip at large lifting height. Excessive Crane tip motion affects the dynamic responses of the lifted components and subsequently affects the safety and efficiency of operations. The present study addresses the effects of soil behaviour modeling of a typical jack-up Crane Vessel on the dynamic motion responses of a wind turbine blade during installation using a fully coupled method. The coupled method account for wind loads on the blade and the Vessel hull, wave loads on the Vessel legs, soil-structure interaction, structural flexibility of the Vessel legs and Crane, and the mechanical wire couplings. Three models for the soil-leg interactions and two soil types are considered. The foundation modeling is found to have vital effects on the system dynamic motion responses. The characteristics of system motion differ under different types of soil. Compared to the combined linear spring and damper model, the simplified pinned and fixed foundations respectively lead to significant overestimation and underestimation of the motion responses of the blade during installation by jack-up Crane Vessels. To ensure safe and efficient offshore operations, detailed site specific soil properties should be used in numerical studies of offshore Crane operations using jack-up Crane Vessels.
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Numerical modeling and analysis of the dynamic motion response of an offshore wind turbine blade during installation by a jack-up Crane Vessel
Ocean Engineering, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir Moan, Eric Van BurenAbstract:Abstract Jack-up Crane Vessels are commonly used to install offshore wind turbine blades and other components. A jack-up Crane Vessel is subjected to wind and wave loads, which cause motion at Crane tip. Excessive motion at Crane tip can lead to failure of lifting operations. Therefore, the Crane tip motion should be properly assessed for jack-up Crane Vessels. In this study, a fully coupled model is developed for a typical elevated jack-up Crane Vessel, considering the hydrodynamic and aerodynamic loads on the Vessel, the soil-structure interaction, and the structural flexibility of the jack-up legs and Crane. The Vessel model developed is further coupled with the SIMO-Aero code to achieve a fully coupled aero-hydro-soil-elastic-mechanical code SIMO-RIFLEX-Aero for numerical modeling and dynamic analysis of offshore single blade installation using jack-up Crane Vessels. The SIMO-RIFLEX-Aero code is then applied to study the dynamic response of the DTU 10 MW wind turbine blade installed by a typical jack-up Crane Vessel under various wind and wave conditions. The results show that significant motion is induced at Crane tip, mainly due to wave loads. It is important to consider the structural flexibility of the jack-up legs and Crane when modeling the installation of offshore wind turbine blades.
Shi Weifeng - One of the best experts on this subject based on the ideXlab platform.
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failure modes and effects analysis of large Crane Vessel s power system
Power system technology, 2010Co-Authors: Shi WeifengAbstract:In this paper,the detailed method of implementing failure modes and effects analysis (FMEA) for the large Crane Vessel’s power system (LCVPS) is introduced,and FMEA is developed from the level of system down to the level of equipment.The following are analyzed: the potential failure modes of various function modules (such as the power generation module,the power distribution module and the lifting module) in the LCVPS,as well as those of specific devices,which realize the corresponding functions in these modules.The causes,the local effects and the end effects of the potential failures are also discussed.Finally,by using the Matlab to perform modeling and failure simulation analysis for the LCVPS,the quantitative failure data are obtained,which is helpful in taking effective measures to remove failures as soon as possible and to enhance reliability of the system.
Zhengshun Cheng - One of the best experts on this subject based on the ideXlab platform.
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Numerical study on the feasibility of offshore single blade installation by floating Crane Vessels
Marine Structures, 2019Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir MoanAbstract:Abstract Compared with jack-up Crane Vessels that are now widely used in offshore wind turbine installation, floating Crane Vessels are more flexible with respect to working water depth and are much faster in relocation. They are thus a promising alternative to install offshore wind turbine components, especially in intermediate and deep water. However, the wave-induced motions of the floating Vessels make the operations challenging. This study deals with a preliminary feasibility study on offshore single blade installation using floating Crane Vessels. Two typical floating Crane Vessels are considered, i.e., a mono-hull Vessel and a semi-submersible Vessel. They are assumed to be equipped with dynamic positioning systems that can well mitigate the slowly varying horizontal motions. Their overall performance during the blade installation is numerically evaluated by comparing their performance against a typical jack-up Crane Vessel. The Crane dynamics plays a less important role for blade installation by floating Vessels, compared to the jack-up Crane Vessel. The floating Vessels’ wave-induced motion greatly affects the blade motion. The semi-submersible Vessel causes a much smaller blade motion than the mono-hull Vessel. The results indicate that it is feasible to install offshore wind turbine blades by using floating Crane Vessels provided that the Vessel type is properly selected. From the operability point of view, semi-submersible Vessels are more feasible than mono-hull Vessels for offshore single blade installations.
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Effect of Foundation Modeling of a Jack-Up Crane Vessel on the Dynamic Motion Response of an Offshore Wind Turbine Blade During Installation
ASME 2018 1st International Offshore Wind Technical Conference, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Zhen Gao, Torgeir MoanAbstract:Nowadays, there is an increasing demand for use of jack-up Crane Vessels to install offshore wind turbines. These Vessels usually have shallow soil penetration during offshore Crane operations because of the requirement of frequent repositioning. The soil-structure interaction should thus be properly modeled for evaluating the motion responses, especially at Crane tip at large lifting height. Excessive Crane tip motion affects the dynamic responses of the lifted components and subsequently affects the safety and efficiency of operations. The present study addresses the effects of soil behaviour modeling of a typical jack-up Crane Vessel on the dynamic motion responses of a wind turbine blade during installation using a fully coupled method. The coupled method account for wind loads on the blade and the Vessel hull, wave loads on the Vessel legs, soil-structure interaction, structural flexibility of the Vessel legs and Crane, and the mechanical wire couplings. Three models for the soil-leg interactions and two soil types are considered. The foundation modeling is found to have vital effects on the system dynamic motion responses. The characteristics of system motion differ under different types of soil. Compared to the combined linear spring and damper model, the simplified pinned and fixed foundations respectively lead to significant overestimation and underestimation of the motion responses of the blade during installation by jack-up Crane Vessels. To ensure safe and efficient offshore operations, detailed site specific soil properties should be used in numerical studies of offshore Crane operations using jack-up Crane Vessels.
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Numerical modeling and analysis of the dynamic motion response of an offshore wind turbine blade during installation by a jack-up Crane Vessel
Ocean Engineering, 2018Co-Authors: Yuna Zhao, Zhengshun Cheng, Peter Christian Sandvik, Zhen Gao, Torgeir Moan, Eric Van BurenAbstract:Abstract Jack-up Crane Vessels are commonly used to install offshore wind turbine blades and other components. A jack-up Crane Vessel is subjected to wind and wave loads, which cause motion at Crane tip. Excessive motion at Crane tip can lead to failure of lifting operations. Therefore, the Crane tip motion should be properly assessed for jack-up Crane Vessels. In this study, a fully coupled model is developed for a typical elevated jack-up Crane Vessel, considering the hydrodynamic and aerodynamic loads on the Vessel, the soil-structure interaction, and the structural flexibility of the jack-up legs and Crane. The Vessel model developed is further coupled with the SIMO-Aero code to achieve a fully coupled aero-hydro-soil-elastic-mechanical code SIMO-RIFLEX-Aero for numerical modeling and dynamic analysis of offshore single blade installation using jack-up Crane Vessels. The SIMO-RIFLEX-Aero code is then applied to study the dynamic response of the DTU 10 MW wind turbine blade installed by a typical jack-up Crane Vessel under various wind and wave conditions. The results show that significant motion is induced at Crane tip, mainly due to wave loads. It is important to consider the structural flexibility of the jack-up legs and Crane when modeling the installation of offshore wind turbine blades.