@article{ author = {AlizadehKharkeshi, Behrad and Shafaghat, Rouzbeh and Alamian, Rezvan and AghajaniAfghan, Amir Hossei}, title = {Experimental & Analytical Hydrodynamic Behavior Investigation of an Onshore OWC-WEC Imposed to Caspian Sea Wave Conditions}, abstract ={In this paper, the effect of the draft depth (as a dimensionless number) and characteristics of the incident wave on free surface oscillation, velocity, and the output power of an OWC has been analytically and experimentally investigated. Therefore, the governing equations of hydrodynamic performance inside the oscillating water column chamber were first presented by assuming a mathematical model based on the potential flow theory. Then, a 1:10 single chamber OWC has been experimentally investigated in a wave tank, by considering the Caspian Sea wave characteristics. Comparing the obtained results showed that there is a good agreement between the theoretical solution and experimental test data. According to the results, increasing the frequency of the incident wave increases the free surface oscillation outside the chamber, while the results inside the OWC are different. In other words, under these conditions, free-surface oscillations inside the OWC and subsequently, the velocity and flow rate of the orifice decrease. So, the power generated will decrease too. Also, the effects of draft depth have been theoretically and experimentally analyzed for three depths and turned out that increasing the depth of drafts from 5 to 25 cm and frequency from 32 to 42 rpm causes a decrease in power generation.}, Keywords = {OWC Device,Wave Energy,Caspian Sea,Experimental Test,Wave Effect}, volume = {14}, Number = {0}, pages = {1-12}, publisher = {Iranian Association of Naval Architecture & Marine Engineering}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmt.ir/article-1-712-en.html}, eprint = {http://ijmt.ir/article-1-712-en.pdf}, journal = {International Journal of Maritime Technology}, issn = {2345-6000}, eissn = {2476-5333}, year = {2020} } @article{ author = {Sharifi, Seyed Mohammad Hossein and Edalat, Pedram and Najafi, Babak and Bolfakeh, Masou}, title = {Numerical Assessment of Tight-Fit Sleeve Clamp in the Repair Process of Cracked Submarine Pipelines}, abstract ={The present research addresses the crack arrest in the submarine pipeline under internal pressure, axial force, and bending moment. The main purpose of the research is to consider tight-fit sleeves as a solution to crack arrest. The stress intensity factor criteria are used to describe the crack behavior. It should be noted that the cracks examined here are inclined through-thickness cracks, which the ABAQUS commercial software used to simulate them. It's noteworthy that Mode I fracture is dealt with, and the other fracture modes are omitted. The results show that the tight-fit sleeves, preferentially arrest the inclined cracks; so that the amounts of the stress intensity factors decrease for all the cracks except for the circumferential cracks to the extent that they become closed. As a result, their growth stops in practice; however, it best reduces the stress intensity factors by up to 65.36% at the circumferential cracks, and their amounts remain non-negative. Tight-fit sleeves create a pressurized region around the inclined cracks. This causes  that inclined cracks remain closed.}, Keywords = {Crack arrest,Stress intensity factors,Inclined cracks,Tight-fit sleeve,Submarine pipelines}, volume = {14}, Number = {0}, pages = {13-20}, publisher = {Iranian Association of Naval Architecture & Marine Engineering}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmt.ir/article-1-692-en.html}, eprint = {http://ijmt.ir/article-1-692-en.pdf}, journal = {International Journal of Maritime Technology}, issn = {2345-6000}, eissn = {2476-5333}, year = {2020} } @article{ author = {Jafarzadeh, Sepideh and Khedmati, Mohammad Rez}, title = {Progressive Collapse Analysis of a Composite Ship Hull Girder under Vertical Bending using Finite Element Method}, abstract ={This paper presents the collapse behaviour of a composite ship hull girder under vertical bending. Finite element method is used to provide valuable information regarding moment-curvature relationships and progressive failure characteristics of the composite ship hull girder. The analysis is carried out using ANSYS 12.0 finite element software. The response of the structure to the incrementally-increased sagging and hogging bending moments has been implemented and studied. }, Keywords = {Composite ship hull girder, Vertical bending, Progressive failure, Ultimate strength, Finite Element Method (FEM)‎.}, volume = {14}, Number = {0}, pages = {21-32}, publisher = {Iranian Association of Naval Architecture & Marine Engineering}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmt.ir/article-1-684-en.html}, eprint = {http://ijmt.ir/article-1-684-en.pdf}, journal = {International Journal of Maritime Technology}, issn = {2345-6000}, eissn = {2476-5333}, year = {2020} } @article{ author = {Zeinabi, Ali and Kohansal, Ahmadrez}, title = {Numerical modeling of sediment transport patterns under the effects of waves and tidal currents at Pars port complex inlet}, abstract ={This study aimed to investigate the sedimentation mechanism at Pars port complex inlet (petrochemical and services ports in Iran) under the effects of wind-waves and tidal currents and to provide solutions to reduce sedimentation by changing the port plan. For this purpose, at first, the modeling of changes in water level and tidal currents in the area was conducted. The results for the currents and waves were evaluated and validated using the measured field data. The one-dimensional sediment transport potential was calculated by about 33,000 cubic meters per year. The analysis of two-dimensional sediment transport phenomena within the ports and inlets showed that tidal currents patterns that are parallel to the coast and the waves in the region are the most important factors in sedimentation. Accordingly, to minimize sedimentation and to investigate the effect of the geometric shape of the port, three configurations were proposed for ports, and the patterns of sedimentation were evaluated in the new arrangements.}, Keywords = {Sediment Transport,Waves,Tidal Currents,Geometry Shape of Ports,Pars Ports}, volume = {14}, Number = {0}, pages = {33-40}, publisher = {Iranian Association of Naval Architecture & Marine Engineering}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmt.ir/article-1-701-en.html}, eprint = {http://ijmt.ir/article-1-701-en.pdf}, journal = {International Journal of Maritime Technology}, issn = {2345-6000}, eissn = {2476-5333}, year = {2020} } @article{ author = {Sharifi, Seyed Mohammad Hossein and Pirali, Nima and Najafi, Babak}, title = {Investigation of Available Configurations for Flexible Risers in Shallow Water}, abstract ={Flexible risers have been used widely in recent years for floating structure in shallow and deep water. Flexible risers have various configurations and each configuration has its specific charectresitics that helps the riser to solve the problems that exist in shallow and deep water. Selecting and designing the best configuration for flexible risers in shallow water, like deep water, present many challenges, some of these challenges can be addressed: high vessel displacement compared to the water depth, minimum riser clearance with the seabed or sea surface or the vessel keel, bending radius limitation and etc. The aim of this paper is to investigate the traditional configurations like lazy wave and pliant wave and to compare them with a new configuration like weight added wave for the riser with 15 inches internal diameter in 45m water depth connected to a turret moored floating storage unit. It is concluded that the traditional configuration can not solve the sea surface clearance problem when the riser is empty condition, in this condition the weight of riser is decreased and the buoyancy force is become higher than riser weight and lift the riser up and the riser become flooded on the sea surface. To preventing the riser from flooding on the sea surface it’s needed to use configuration with added mass. Also concluded that using added mass in touch down zone (TDZ) reduces the tension in PLEM connection point about 89% . Also concluded that the minimum bending radius for weight added wave configuration is increased about 29% in compared with traditional configurations. }, Keywords = {Flexible riser,Configurations,Shallow water,FSU}, volume = {14}, Number = {0}, pages = {41-50}, publisher = {Iranian Association of Naval Architecture & Marine Engineering}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmt.ir/article-1-686-en.html}, eprint = {http://ijmt.ir/article-1-686-en.pdf}, journal = {International Journal of Maritime Technology}, issn = {2345-6000}, eissn = {2476-5333}, year = {2020} } @article{ author = {Arabshahy, Erfan and Kasaeyan, Mohammad and Shabakhty, Naser}, title = {Evaluation of environmental parameters in Floatover installation in mating stage using Design of Experiment methods}, abstract ={This paper appraises the environmental parameters affecting the Floatover installation method. While this method demands extensive logistics, hardware, and planning from the first stage till the last, Environmental parameters are the main sources of creating external forces. Comprehension of the environmental features and their influence plays a significant role. In this paper, the application of the Design of experiments (DoE) in the offshore installation is examined. This methodology involves the mathematical procedures of designing experiments that allow a precise and effective evaluation of response features using the least number of analyses. By using response surface methodology and Taguchi design, which are methods of DoE, the significance of each parameter is assessed and a function is developed that holds the response with respect to the input environmental parameters. The magnitude of the impact forces acting on the leg mating unit is chosen as the response. Hydrodynamic time domain analysis based on these methods was done. This study was performed for a semi heavy weight topside and a typical T-shaped barge with six degrees of freedom for the Persian Gulf region.}, Keywords = {Floatover, Offshore Installation,Design of Experiments,Response Surface Methodology, Taguchi Method, Leg Mating Unit}, volume = {14}, Number = {0}, pages = {51-61}, publisher = {Iranian Association of Naval Architecture & Marine Engineering}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmt.ir/article-1-713-en.html}, eprint = {http://ijmt.ir/article-1-713-en.pdf}, journal = {International Journal of Maritime Technology}, issn = {2345-6000}, eissn = {2476-5333}, year = {2020} }