The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Joško Parunov - One of the best experts on this subject based on the ideXlab platform.
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residual ultimate strength assessment of double hull Oil Tanker after collision
Engineering Structures, 2017Co-Authors: Joško Parunov, Smiljko Rudan, Branka Bužančić PrimoracAbstract:The aim of the present study is the assessment of a residual ultimate strength of an Aframax-class double hull Oil Tanker damaged in collision. A contribution to the research of the problem is given in a systematic investigation of the influence of the rotation of neutral axis (NA), which is performed by imposing appropriate boundary conditions. Nonlinear finite element method (NFEM), using explicit dynamic integration method implemented in LS-Dyna, is employed. NFEM results are compared with the IACS CSR progressive collapse analysis (PCA) method. Residual strength diagrams are developed for a rapid residual ultimate longitudinal strength assessment in both sagging and hogging and accounting for correction factor because of the rotation of NA. Following this, developed diagrams are compared with previously published researches. The results of this study may be used by classification societies in a Rules development process, in the risk assessment studies of the maritime transportation and for a quick calculation of the hull girder residual strength of a damaged ship in the situation requiring emergency response action.
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structural reliability assessment of an Oil Tanker accidentally grounded in the adriatic sea
ASME 2017 36th International Conference on Ocean Offshore and Arctic Engineering (OMAE2017), 2017Co-Authors: Maro Corak, Joško Parunov, Guedes C SoaresAbstract:The aim of the paper is to present a methodology for the assessment of the structural reliability of an Oil Tanker damaged in a hypothetical grounding accident in the Adriatic Sea. The grounding accident affects the ultimate hull girder capacity in the damaged region, the still water bending moment (SWBM) distribution along the vessel as well as the vertical wave bending moments (VWBM). The extent of the damage on the ship’s hull after a grounding accident depends on several parameters such as ship`s speed, rock size, penetration depth, longitudinal and transversal location of stranding along the hull. These parameters are in the present study assumed as random variables, described by probability density functions. Based on defined statistical properties, random realizations of grounding parameters are simulated by Monte Carlo (MC) simulation. For each such random grounding scenario, the damage size is calculated by the surrogate model based on numerical grounding simulations. Residual ultimate strength and SWBM distribution are determined based on the size and location of the damage. VWBM is calculated for average sea state in the area with increased risk of grounding accident in the Adriatic Sea. Structural reliability analysis is employed to determine the safety index with respect to the ultimate hull girder failure for salvage period of 12 hours. As each grounding scenario results in different hull- girder reliability, histogram of safety indices is obtained representing new measures for the performance assessment of the damaged ship.
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ultimate hull girder strength based reliability of a double hull Oil Tanker after collision in the adriatic sea
Ships and Offshore Structures, 2017Co-Authors: Joško Parunov, Smiljko Rudan, Maro CorakAbstract:The aim of this paper is to present a methodology for the assessment of the structural reliability of an Oil Tanker damaged in a hypothetical collision accident in the Adriatic Sea. Monte Carlo sim...
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Statistics of still water bending moment of damaged Suezmax Oil Tanker
2015Co-Authors: Branka Bužančić Primorac, Vedran Slapničar, Ivan Munić, Vjekoslav Grubiš Ić, Maro Ćorak, Joško ParunovAbstract:The aim of the paper is to create statistical model of still water bending moment of Suezmax double hull Oil Tanker damaged in collision or grounding accident, by applying the same random variables assumption and concept already developed for an Aframax Oil Tanker. Monte Carlo simulation is employed to generate possible damage scenarios according to IMO Resolution MEPC.110(49) from 2003. For each damage case, maximum bending moments for whole ship and damaged area are calculated by hydrostatic software. Histograms of relative bending moments are then created and appropriate probability distribution fitted. The results are treated in a way to take into account correlation between damage location and maximum bending load. Comparison of the Aframax and Suezmax probability distribution parameters is also performed. The purpose of developed probabilistic models is application in structural reliability studies of damaged ship.
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residual strength of damaged Oil Tanker in the adriatic sea
NAV 2012 17th International Conference on Ships and Shipping Research, 2012Co-Authors: Zrinka Buric, Branka Bužančić Primorac, Joško ParunovAbstract:Accidental damages of ships can occur in any number of ways being the two most concerning ones the collision with other ships and hard grounding on seabed. When a ship is damaged, the operators need to decide on immediate repair actions by evaluating the effects of the damage on the safety of the ship by considering simultaneously effects of the damage in the hull girder ultimate bending moment and in the applied loads. Recent disaster of the Tanker „Prestige“ in 2002 close to the Spanish coast clearly showed that the ship in damaged condition can be broken and sink as the most unfavourable outcome of such accident with likely spillalge of a large amount of Oil onboard. The aim of the paper is to investigate if there is possibility of ultimate hull girder collapse of damaged Oil Tanker in the Adriatic Sea. Location and extent of the damage due to grounding or collision are defined according to the ABS document „Guide for Assessing Hull-Girder Residual Strength for Tankers“. Still water bending moments of damaged Oil Tanker are estimated using data from available references. Wave loads are calculated by seakeeping software applying 3D panel method. The most probable extreme values of the vertical wave bending moment during the towing period of damaged ship is calculated using available wave statistics for the Adriatic Sea. Ultimate vertical bending capacity of the intact and damaged ship are calculated by MARS software and compared with other similar studies. Finally, safety factors against collapse of damaged ship are determined and corresponding conclusions are drawn.
Maro Corak - One of the best experts on this subject based on the ideXlab platform.
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structural reliability assessment of an Oil Tanker accidentally grounded in the adriatic sea
ASME 2017 36th International Conference on Ocean Offshore and Arctic Engineering (OMAE2017), 2017Co-Authors: Maro Corak, Joško Parunov, Guedes C SoaresAbstract:The aim of the paper is to present a methodology for the assessment of the structural reliability of an Oil Tanker damaged in a hypothetical grounding accident in the Adriatic Sea. The grounding accident affects the ultimate hull girder capacity in the damaged region, the still water bending moment (SWBM) distribution along the vessel as well as the vertical wave bending moments (VWBM). The extent of the damage on the ship’s hull after a grounding accident depends on several parameters such as ship`s speed, rock size, penetration depth, longitudinal and transversal location of stranding along the hull. These parameters are in the present study assumed as random variables, described by probability density functions. Based on defined statistical properties, random realizations of grounding parameters are simulated by Monte Carlo (MC) simulation. For each such random grounding scenario, the damage size is calculated by the surrogate model based on numerical grounding simulations. Residual ultimate strength and SWBM distribution are determined based on the size and location of the damage. VWBM is calculated for average sea state in the area with increased risk of grounding accident in the Adriatic Sea. Structural reliability analysis is employed to determine the safety index with respect to the ultimate hull girder failure for salvage period of 12 hours. As each grounding scenario results in different hull- girder reliability, histogram of safety indices is obtained representing new measures for the performance assessment of the damaged ship.
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ultimate hull girder strength based reliability of a double hull Oil Tanker after collision in the adriatic sea
Ships and Offshore Structures, 2017Co-Authors: Joško Parunov, Smiljko Rudan, Maro CorakAbstract:The aim of this paper is to present a methodology for the assessment of the structural reliability of an Oil Tanker damaged in a hypothetical collision accident in the Adriatic Sea. Monte Carlo sim...
C. Guedes Soares - One of the best experts on this subject based on the ideXlab platform.
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Fatigue damage assessment of corroded Oil Tanker details based on global and local stress approaches
International Journal of Fatigue, 2012Co-Authors: K. Tran Nguyen, Yordan Garbatov, C. Guedes SoaresAbstract:Abstract Fatigue damage assessment of double hull Oil Tanker structural details is performed, based on global and local structural finite element models. The wave-induced vertical and horizontal bending moments, as well as local pressure loads are accounted for in the fatigue damage calculations. Local stress analyses are considered based on the notch stress approach. Time-dependent stresses as a function of corrosion deterioration are analyzed based on nonlinear corrosion wastage during the design life of ship. The effective notch stress approach is applied for analyzing the stress distributions and the fatigue damage of the welded joint at two hotspots. The hotspots are located between the flat bar stiffener of a transverse web frame and the flange of a longitudinal stiffener at the side shell of a Tanker ship hull. The details under consideration are modeled separately in a fine mesh employing the sub model techniques. Finally the fatigue damage assessment accounting for corrosion deterioration of the considered hotspots is analyzed.
Jinhwa Song - One of the best experts on this subject based on the ideXlab platform.
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alternative approaches to the crude Oil Tanker routing and scheduling problem with split pickup and split delivery
European Journal of Operational Research, 2015Co-Authors: Frank Hennig, Bjorn Nygreen, Kevin C Furman, Jinhwa SongAbstract:Abstract The crude Oil Tanker routing and scheduling problem with split pickup and split delivery is a maritime transportation task where an industrial operator needs to ship different types of crude Oil from production sites to Oil refineries. The different crude Oils are supplied and demanded in many ports in certain time windows. Pickup and delivery quantities are known in advance but no pairing of pickup and delivery needs to be predefined and can be decided together with shipment quantities during optimization. Pickup and delivery quantities may be split arbitrarily among the ships in the fleet. We compare two alternative path flow model approaches to investigate their degree of applicability in a column generation setup. For this purpose we apply route pregeneration prior to optimization. The first approach uses continuous decision variables for pickup and delivery to decide on shipment quantities. In the considerably shorter second formulation cargo quantities are discretized and included into the paths. The second approach is capable to solve larger instances and is more efficient in terms of computational performance, however solution quality may decrease due to the discretization.
Guedes C Soares - One of the best experts on this subject based on the ideXlab platform.
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structural reliability assessment of an Oil Tanker accidentally grounded in the adriatic sea
ASME 2017 36th International Conference on Ocean Offshore and Arctic Engineering (OMAE2017), 2017Co-Authors: Maro Corak, Joško Parunov, Guedes C SoaresAbstract:The aim of the paper is to present a methodology for the assessment of the structural reliability of an Oil Tanker damaged in a hypothetical grounding accident in the Adriatic Sea. The grounding accident affects the ultimate hull girder capacity in the damaged region, the still water bending moment (SWBM) distribution along the vessel as well as the vertical wave bending moments (VWBM). The extent of the damage on the ship’s hull after a grounding accident depends on several parameters such as ship`s speed, rock size, penetration depth, longitudinal and transversal location of stranding along the hull. These parameters are in the present study assumed as random variables, described by probability density functions. Based on defined statistical properties, random realizations of grounding parameters are simulated by Monte Carlo (MC) simulation. For each such random grounding scenario, the damage size is calculated by the surrogate model based on numerical grounding simulations. Residual ultimate strength and SWBM distribution are determined based on the size and location of the damage. VWBM is calculated for average sea state in the area with increased risk of grounding accident in the Adriatic Sea. Structural reliability analysis is employed to determine the safety index with respect to the ultimate hull girder failure for salvage period of 12 hours. As each grounding scenario results in different hull- girder reliability, histogram of safety indices is obtained representing new measures for the performance assessment of the damaged ship.
