References of "Rigo, Philippe"
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See detailPrediction of remaining fatigue life of welded joints in wind turbine support structures considering strain measurement and a joint distribution of oceanographic data
Mai, Anh Quang ULiege; Morato Dominguez, Pablo Gabriel ULiege; Rigo, Philippe ULiege

in Marine Structures (2019), 66

Reassessing the remaining fatigue life of the wind turbine support structures becomes more and more crucial for operation, maintenance, and life extension when they are reaching the end of their design ... [more ▼]

Reassessing the remaining fatigue life of the wind turbine support structures becomes more and more crucial for operation, maintenance, and life extension when they are reaching the end of their design service life. By using measured oceanographic and strain data, each year, remaining fatigue life can be updated to adapt the operation to real loading conditions. Previous works have not put attention to address the complexity of offshore loading combinations and as-constructed state of the structure in estimating structural responses for fatigue behaviour to stochastically predict the remaining fatigue life. The present paper links the oceanographic data to fatigue damage by using measured strain, and uses the Bayesian approach to update the joint distribution of the oceanographic data. Consequently, the failure probability of the support structure can be updated and so the predicted fatigue life. The year-to-year variation of the 10-min mean wind speed, the unrepresentativeness of measured strain, the measurement uncertainty, and corrosion are considered together with uncertainties in Miner′s rule and S–N curves. The present research shows that the real oceanographic data can be used to adjust the predicted remaining fatigue life and eventually give decision support for the wind turbine operation. [less ▲]

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See detailPOMDP based Maintenance Optimization of Offshore Wind Substructures including Monitoring
Morato Dominguez, Pablo Gabriel ULiege; Nielsen, Jannie S.; Mai, Anh Quang ULiege et al

in Proceedings of the 13th International Conference on Applications of Statistics and Probability in Civil Engineering (ICASP13) (2019, May 27)

Sequential decision making under uncertainty is a complex task limited normally by computational requirements. A novel methodology is proposed in this paper to identify the optimal maintenance strategy of ... [more ▼]

Sequential decision making under uncertainty is a complex task limited normally by computational requirements. A novel methodology is proposed in this paper to identify the optimal maintenance strategy of a structural component by using a point-based Partially Observable Markov Decision Process (POMDP). The framework integrates a dynamic bayesian network to track the deterioration over time with a POMDP model for the generation of a dynamic policy. The methodology is applied to an example quantifying whether a monitoring scheme is cost effective. This complex decision problem comprised of 200 damage states is solved accurately within 60 seconds of computational time. [less ▲]

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See detailReliability assessment of aging miter gates in the presence of corrosion and fatigue
Dang Van Thuong, ULiege; Mai, Anh Quang ULiege; Morato Dominguez, Pablo Gabriel ULiege et al

Poster (2019, February 18)

Aging Hydraulic steel structures, especially lock gates suffer from structural deterioration with fatigue and corrosion, resulting in a reduction of their resistance. A prolonged exposure to these hazards ... [more ▼]

Aging Hydraulic steel structures, especially lock gates suffer from structural deterioration with fatigue and corrosion, resulting in a reduction of their resistance. A prolonged exposure to these hazards results in a reduction of structural resistance which can lead to failure. This research presents an approach to compute the reliability of aging miter gates in the presence of corrosion and fatigue. First order reliability index method is used to calculate reliability of the structure. An example of an aging miter gate is used for demonstration. [less ▲]

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See detailPOMDP-Based Risk Maintenance Planning for Offshore Wind Substructures
Morato Dominguez, Pablo Gabriel ULiege; Nielsen, Jannie S.; Rigo, Philippe ULiege

Poster (2019, February 18)

This work presents a novel methodology to identify the optimal maintenance strategy for an offshore wind structural component, providing a flexible and reliable support to decision-making and balancing ... [more ▼]

This work presents a novel methodology to identify the optimal maintenance strategy for an offshore wind structural component, providing a flexible and reliable support to decision-making and balancing inspection, repair and failure costs. The methodology is tested for a tubular joint through a 60-states POMDP, obtaining the optimal maintenance policy in low computational time and in good agreement with common Risk-Based Inspection (RBI) methods. [less ▲]

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See detailPoint-based POMDP Risk Based Inspection of Offshore Wind Substructures
Morato Dominguez, Pablo Gabriel ULiege; Nielsen, Jannie Sonderkær; Mai, Anh Quang ULiege et al

in Caspeele, Robby; Taerwe, Luck; Frangopol, Dan M. (Eds.) Life Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision (2019)

This article presents a novel methodology to select the optimal maintenance strategy of an offshore wind structural component, providing a flexible and reliable support to decision-making and balancing ... [more ▼]

This article presents a novel methodology to select the optimal maintenance strategy of an offshore wind structural component, providing a flexible and reliable support to decision-making and balancing inspection, repair and failure costs. The procedure to create a “Point-Based” Partially Observable Markov Decision Process (POMDP) is described and a calibrated fracture mechanics model is introduced to assess the deterioration of the structure. The methodology is then tested for a tubular joint through a 60-states POMDP, obtaining the optimal maintenance policy in low computational time and in good agreement with common Risk-Based Inspection (RBI) methods. [less ▲]

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See detailUsing SCADA in updating failure probability of a monopile support structure
Mai, Anh Quang ULiege; Weijtjens, Wout; Christof, Devriendt et al

in EAWE PhD Seminar 2018 Proceedings (2018, September 18)

Assessment of existing offshore wind turbine support structures is crucial for a condition-based inspection planning and life extension decision. This paper aims at utilizing SCADA as new information to ... [more ▼]

Assessment of existing offshore wind turbine support structures is crucial for a condition-based inspection planning and life extension decision. This paper aims at utilizing SCADA as new information to update failure probability of monopile support structures in fatigue failure mode. The SCADA was collected from a Belgian offshore wind farm. It is assumed that fatigue loading of the monopile support structure comes mainly from wind action. One-year data of measured strain is used together with the concurrently measured 10-minute wind speed to built the limit state function. Fatigue-critical strain history is derived from the data at three measuring locations on the same circumference. The 10-minute mean wind speed is considered as a random variable and used to calculate the fatigue damage. Fatigue damage is calculated using Miner's rule. The year-to-year variation of the 10-minute mean wind speed, the unrepresentativeness of the measured strain, and the measurement uncertainty are considered together with uncertainties in Miner's rule and the S-N curve. The Bayesian approach is used to update the 10-minute mean wind speed distribution considering measurement data. Consequently, the failure probability of the support structure can be updated. The results show that after three years of measurement, there is no significant differences in the calculated failure probability between cases where the updated 10-minute mean wind speed distribution and the design distribution are used. The load factor applied to the measured stress (e.g. stress concentration factor, corrosion effects, or interpolation factor for unmeasured locations) significantly affects the calculated failure probabilities. In conclusion, the wind measurement data can be used to predict failure probability of the monopile support structure given that a limited concurrently measured strain data is available. Further research is needed to combine the SCADA with inspection data (crack, corrosion) for optimising the inspection plan or a life extension purpose. [less ▲]

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See detailUpdating the failure probability of miter gates based on observation of water levels
Dang Van Thuong, ULiege; Mai, Anh Quang ULiege; Morato Dominguez, Pablo Gabriel ULiege et al

in Structural Integrity (2018, September 05)

Hydraulic steel structures, especially lock gates play a significant role in keeping navigation traffic uninterrupted. After a few decades of operation, many of the welded joints may suffer various ... [more ▼]

Hydraulic steel structures, especially lock gates play a significant role in keeping navigation traffic uninterrupted. After a few decades of operation, many of the welded joints may suffer various degrees of deterioration, primarily due to fatigue. To economically combining crack inspection with a scheduled maintenance of the movable parts of the gate, it is valuable to predict inspection time of the welded joints using the historical operations of the gate, i.e. the variation of water levels. Updating failure probability of welded joint is mature in the offshore industry, but it is rarely applied for inland navigation lock gates where the contribution to fatigue failure comes from the variation of water pressures during operation of the lock gates. The scope of this paper is to predict the inspection time of a welded joint using the observed water levels from the operational history. The updating of the failure probability is done for three inspection techniques, considering annual probability and repair decisions. The results show the effects of critical annual probability and the probability of detections (PODs) on the update failure probability for a welded joint. [less ▲]

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See detailQuick assessment of the punching resistance of an offshore wind turbine jacket impacted by a ship
Pire, Timothée ULiege; Hsieh, Jing-Ru; Le Sourne, Hervé ULiege et al

in Paik, Jeom Kee; Ehlers, Sören; Ringsberg, Jonas (Eds.) Proceedings of the 3rd International Conference on SHips and Offshore Structures ICSOS2018 (2018, September)

This paper presents a new methodology developed to compute the energy dissipated by plastic deformation of offshore wind turbine jacket punched legs in a ship collision event. Punching may occur on both ... [more ▼]

This paper presents a new methodology developed to compute the energy dissipated by plastic deformation of offshore wind turbine jacket punched legs in a ship collision event. Punching may occur on both impacted and rear legs at the connection with compressed braces. Using semi-analytical expressions derived to assess the resistant force and the deformation energy of a punched leg and the internal axial force in each brace, the connections where punching is initiated are identified. Then, the punching deformation at each connection is computed and linked to the ship penetration through the jacket. The corresponding resistant force and dissipated energy is finally assessed and transmitted to the impact point. This methodology is successfully validated by comparison with nonlinear finite element simulations. [less ▲]

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See detailRisk Based Maintenance of Offshore Wind Substructures
Morato Dominguez, Pablo Gabriel ULiege; Rigo, Philippe ULiege

Conference (2018, June 29)

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See detailAdvances on the methodology for the Inland Waterways Classification for South America
Jaimurzina, Azhar; Rigo, Philippe ULiege

in PIANC CONGRESS 2018 (2018, May)

There is, therefore, a need for a common classification for South America which would result in a more efficient, transparent and sustainable use of inland water transport and logistics services, in ... [more ▼]

There is, therefore, a need for a common classification for South America which would result in a more efficient, transparent and sustainable use of inland water transport and logistics services, in general. Since October 2016, ECLAC and PIANC are working together in close collaboration with the experts from South American countries on a common classification for the inland waterways and the first results of this work will be presented in this paper. The paper will offer: • Overview of the inland waterways’ classifications in South America • Identification of the main parameters (i.e. metrics) for the harmonized South American classification • Proposals on the classification methodology • Guidelines and recommendations for further development and application. [less ▲]

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See detailProceedings of the 20th International Ship and Offshore Structures Congress Volume 2 (ISSC 2018)
Mirek, L. Kaminski; Rigo, Philippe ULiege

Book published by IOS Press - Volume 2 (2018)

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See detailProceedings of the 20th International Ship and Offshore Structures Congress Volume 1 (ISSC 2018)
Mirek, L. Kaminski; Rigo, Philippe ULiege

Book published by IOS Press - Volume 1 (2018)

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See detailAnalytical formulations to assess the energy dissipated at the base of an offshore wind turbine jacket impacted by a ship
Pire, Timothée ULiege; Le Sourne, Hervé ULiege; Echeverry Jaramillo, Sara ULiege et al

in Marine Structures (2018), 59

This paper presents some new analytical developments carried out to assess the energy dissipated plastically at the base of an offshore wind turbine jacket impacted by a ship. The jacket components ... [more ▼]

This paper presents some new analytical developments carried out to assess the energy dissipated plastically at the base of an offshore wind turbine jacket impacted by a ship. The jacket components involved in this mechanism are both the impacted leg and the rear leg, considered as clamped at the foundation level, as well as the horizontal bottom brace considered as rigidly fixed on the legs. The foundation system is assumed to be piles inserted into sleeves with cement grout. The base of the jacket is divided into four zones and a kinematically admissible displacement field is assumed for each of them. Based on plastic limit analysis, new analytical formulations are derived to assess the resistance and the dissipated energy for each considered area and therefore of the whole jacket base. To validate the method, full scale ship-jacket collisions are simulated both analytically and numerically and plastic energy dissipated at the base of the jacket is compared successfully with nonlinear finite element simulation results. [less ▲]

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See detailA discrete-event simulation approach to evaluate the effect of stochastic parameters on offshore wind farms assembly strategies
Tekle Muhabie, Y.; Rigo, Philippe ULiege; Cepeda, M. et al

in Ocean Engineering (2018), 149

The wind industry is facing new challenges due to the planned construction of thousands of offshore wind turbines all around the world. However, with their increasing distance from the shore, greater ... [more ▼]

The wind industry is facing new challenges due to the planned construction of thousands of offshore wind turbines all around the world. However, with their increasing distance from the shore, greater water depths, and increasing sizes of the plants, the industry has to face the challenge to develop sustainable installation procedures. Important limiting factors for offshore wind farm installation are the weather conditions and installation strategies. In this context, the focus of this research is the investigation of the most effective approach to installing offshore wind farms at sea, including the effects of weather conditions. This target is achieved through the implementation of a discrete-event simulation approach which includes the analysis of the environmental conditions, distance matrix, vessel characteristics, and assembly scenarios. The model maps the logistics chain in the offshore wind industry. A deterministic and a probabilistic metocean data method have been compared and cross validated. The results point to a good agreement between the two considered models, while highlighting the huge risks to the time and cost of the installation due to the stochastic nature of the weather. We suggest that simulations may improve and reduce these risks in the planning process of offshore wind farms. © 2017 Elsevier Ltd [less ▲]

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See detailInnovative Framework for Risk-Based Maintenance Optimization of Offshore Wind Substructures
Morato Dominguez, Pablo Gabriel ULiege; Nielsen, Jannie S.; Rigo, Philippe ULiege

Poster (2017, December 04)

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See detailAnalytical method to assess the crashworthiness of a Floating Offshore Wind Turbine (FOWT)
Echeverry Jaramillo, Sara ULiege; Le Sourne, Hervé; Rigo, Philippe ULiege

Poster (2017, December 04)

With the purpose of using more renewable energies and the decarbonisation of EU, some European countries are implementing floating wind farms, which are closer to traffic lanes. It is important to have a ... [more ▼]

With the purpose of using more renewable energies and the decarbonisation of EU, some European countries are implementing floating wind farms, which are closer to traffic lanes. It is important to have a complete scope of the structure’s response to a ship impact, in order to implement a risk assessment of the floating wind turbines. In this regard, finite elements solvers are widely used nowadays, which provide accurate results but are time-demanding, not suitable for an early design stage. A faster and reliable method is required in order to study a wide range of parameters: impact velocity, impact location, wind-wave-structure interaction, mooring system response and overall dynamics. This poster presents the methodology used to develop an analytical method to compute the crashworthiness of FOWT. [less ▲]

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See detailAssessment of the deformation by punching and at the baseof an offshore wind turbine jacket impacted by a ship
Pire, Timothée ULiege; Le Sourne, Hervé ULiege; Rigo, Philippe ULiege

Poster (2017, December 04)

Renewable energy production systems are expanding very fast to meet the actual energetic issues. Amongst them, offshore wind is a very promising technology as it provides a nearly constant and high ... [more ▼]

Renewable energy production systems are expanding very fast to meet the actual energetic issues. Amongst them, offshore wind is a very promising technology as it provides a nearly constant and high electricity power. However, this growing number of offshore wind turbines increases the collision risk with vessels that needs to be considered during the design phase. Finite elements are widely used and provide accurate results, but are time-demanding, especially when thousands collision scenarios are investigated in a full collision risk analysis. The authors developed analytical formulations in order to compute quickly the crashworthiness of an offshore wind turbine jacket. From numerical simulations, four deformation modes were identified. The methodology and the main developments performed for two of them, namely the punching and the deformation at the base of the jacket, are presented in this poster. These formulations are then integrated in a general algorithm that includes all four modes to compute the total jacket resistance. [less ▲]

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See detailShip collision analysis on Offshore Wind Turbines with monopile foundations
Bela, Andreea ULiege; Le Sourne, Hervé; Rigo, Philippe ULiege

Poster (2017, December 04)

Every year the offshore wind industry is expanding and new offshore wind farms are built in deeper waters and closer to the traffic lanes for commercial and passenger ships leading to possible collision ... [more ▼]

Every year the offshore wind industry is expanding and new offshore wind farms are built in deeper waters and closer to the traffic lanes for commercial and passenger ships leading to possible collision events. The consequences of such events can range from minor structural damage to collapse of the Offshore Wind Turbine (OWT), with probability of ship sinking, pollution and at worst, to loss of human lives. Therefore, a collision risk analysis becomes a necessity in the pre-design stage of an offshore wind farm in order to identify the collision scenarios having the greatest probabilities of occurrence but also the most dangerous ones. The objective of this research is to investigate numerically the influence of the impact velocity and wind loads on the OWT’s behaviour when subjected to ship impact. A 5 MW wind turbine was considered for this research and the striking ship was conservatively assumed to be rigid. The description of the Finite Element model is presented as well as the main results obtained. [less ▲]

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