• Journal of the Society of Naval Architects of Korea
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• v.46 no.6
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• pp.641-649
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• 2009

There were many simulation models that made for validation of industrial environment and estimate of efficiency to be constructed. And there will be more simulation models made for same reason, too. Already, there have been a lot of simulation models in industry field and scholar labs. To reuse these simulation models, it is necessary to find common properties and make the high abstract simulation model. Based on this idea, this study shows to define the high abstract simulation model to be able to specialize in need and to make the software framework for connecting the specific simulation model to the abstract model. And it is held up as the example that applying the simulation framework to the Ship Panel Block shop simulation model.

• Journal of the Korea Society for Simulation
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• v.21 no.1
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• pp.69-79
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• 2012

One of the goals of mass customization is to permit changes in the product to meet specific customer requirements without substantially impacting the cost or delivery schedule. In large assembly manufacturing industries, such as shipbuilding and commercial airplane production, customization takes place by changing components and/or modules, sometimes called interim products. Using shipbuilding as a case study, it is possible to study the impact of such changes using mass customization principles on the schedule. In large assembly manufacturing, mass customization changes would cause changes in engineering time and production time, based on the amount of change required by the customization. This work first proposes a structure for implementing mass customization in shipbuilding and then uses simulation of a simplified, theoretical shipbuilding process to evaluate the impacts of various levels of change on delivery performance.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.411-420
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• 2005

World leading company and research centers have invested much cost and effort into a PLM and digital manufacturing field to obtain their own competitiveness. We have been trying to apply a digital manufacturing, especially simulation to ship production process as a part of PLM implementation for a shipyard. A shipbuilding production system and processes have a complexity and a peculiarity different from other kinds of production systems. So, new analysis and modeling methodology is required to implement digital shipyard. which is a digital manufacturing system for a shipbuilding company. This paper suggests an analysis and simulation modeling methodologies for an implementation of a digital shipyard. New methodologies such as a database-merged simulation, a distributed simulation, a modular simulation with a model library and a 3-tire simulation framework are developed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.6
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• pp.589-601
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• 2016

The hybrid grid was adopted and numerical prediction analysis of propeller unsteady bearing force considering free surface was performed for mode and full-scale KCS hull-propeller-rudder system by employing RANS method and VOF model. In order to obtain the propeller velocity under self-propulsion point, firstly, the numerical simulation for self-propulsion test of full-scale ship is carried out. The results show that the scale effect of velocity at self-propulsion point and wake fraction is obvious. Then, the transient two-phase flow calculations are performed for model and full-scale KCS hull-propeller-rudder systems. According to the monitoring data, it is found that the propeller unsteady bearing force is fluctuating periodically over time and full-scale propeller's time-average value is smaller than model-scale's. The frequency spectrum curves are also provided after fast Fourier transform. By analyzing the frequency spectrum data, it is easy to summarize that each component of the propeller bearing force have the same fluctuation frequency and the peak in BFP is maximum. What's more, each component of full-scale bearing force's fluctuation value is bigger than model-scale's except the bending moment coefficient about the Y-axis.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.19-27
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• 2006

To survive in the current shipbuilding industry it is of vital importance for shipyards to achieve an optimal utilization of resources, make an achievable planning and ensure that this planning is kept. Possible problems should be eliminated before production starts and if unexpected disturbances occur in the actual production the right measures should be taken. Due to the dynamic nature of the production process, the continuous variation in products and the complexity of both, all this can hardly be achieved with conventional static planning and analysis systems. Simulation provides a solution here, since this enables the modelling and evaluation of the dynamic relations between product and production process. After a global introduction to production simulation in general and the application of simulation at the Flensburger shipyard, this paper presents a tool that has been developed to simulate the various complex assembly processes taking place at shipyards. Subsequently the simulation model for the subassembly production at Flensburger, in which this tool is applied, will be discussed.

• Ocean Systems Engineering
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• v.13 no.4
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• pp.367-384
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• 2023

Herein, we present the design and development of an efficient finite element analysis model for thermal plate forming in shipbuilding. Double curvature shells in the ship building industries are primarily formed through the thermal forming technique. Thermal forming involves heating of steel plates using heat sources like oxy-acetylene gas torch, laser, and induction heating, etc. The differential expansion and contraction across the plate thickness cause plastic deformation and bending of plates. Thermal forming is a complex forming technique as the plastic deformation and bending depends on many factors such as peak temperature, heating and cooling rate, depth of heated zone and many other secondary factors. In this work, we develop an efficient finite element analysis model for the thermo-mechanical analysis of thermal forming. Different simulations are reported to study the effect of various parameters affecting the process. Temperature dependent properties are used in the analysis and the finite element analysis model is used to identify the critical flame velocity to avoid recrystallization of plate material. A spring connected plate is modeled for structural analysis using spring elements and that helps in identifying the resultant shapes of various thermal forming patterns. Finally, detailed simulation results are reported to establish the efficacy, applicability and efficiency of the designed and developed finite element analysis model.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.2
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• pp.116-123
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• 2018

These days, geographic information system has released in everyday life and industries. However, the shipyard only uses it to manage the layout of the yard. In this study, we apply the Geographic Information System to shipbuilding block logistics simulation to analyse the behavior of bogies and forklifts carrying blocks and materials in the shipyard. The shipyard manages daily block logistics plans at the execution planning stage. However, since it is a daily plan, it is difficult to respond to an unexpected situation immediately, and application to judge a certain value or higher value is insufficient. Therefore, a simulation model was created using the shape and attribute information inherent in the geographic information system to verify and improve the block logistics of the mid-and long-term yards. Through this simulation model, we will analyse loads on the workplace, stockyard, and road, and contribute to overall logistics improvement from the point of view of resource planning. In addition, the results of the simulation are reflected in the planning, to help support various decisions.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.1
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• pp.69-84
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• 2018

In order to analyze the characteristics of propeller exciting force, the hybrid grid is adopted and the numerical prediction of KCS ship model is performed for hull-propeller-rudder system by Reynolds-Averaged Navier Stokes (RANS) method and volume of fluid (VOF) model. Firstly, the numerical simulation of hydrodynamics for bare hull at oblique state is carried out. The results show that with the increasing of the drift angle, the coefficients of resistance, side force and yaw moment are constantly increasing, and the bigger the drift angle, the worse the overall uniformity of propeller disk. Then, propeller bearing force for hull-propeller-rudder system in oblique flow is calculated. It is found that the propeller thrust and torque fluctuation coefficient peak in drift angle are greater than that in straight line navigation, and the negative drift angle is greater than the positive. The fluctuation peak variation law of coefficient of side force and bending moment are different due to various causes.

• Korean Journal of Computational Design and Engineering
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• v.13 no.1
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• pp.27-35
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• 2008

Digital Virtual Manufacturing is a technology facilitating effective product developments and agile productions via digital models representing the physical and logical schema and the behavior of real manufacturing systems. A digital virtual factory as a well-designed and integrated environment is essential for successful applications of this technology. In this research, we construct a sophisticated digital virtual factory for the section steel shop in a Korean shipbuilding company by 3-D CAD and virtual manufacturing simulation. The NIST-AMRF CIM hierarchical model and workflow analysis using IDEF methodology are also applied. This digital virtual factory can be applied for diverse engineering activities in design, manufacturing and control of the real factory, and improvements in quality of engineering and savings in time from design to production in shipbuilding are possible.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.96-100
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• 2008

In this paper, a experimental and theoretical study is carried out on the hydroelastic vibration for a rectangular bottom and side plate of tank. It is assumed that the tank wall is clamped along the plate edges. The fluid velocity potential is used for the simulation of fluid domain and to obtain the added mass due to plate vibration. It is assumed that the fluid is imcompressible and inviscid. Assumed mode method is utilized to the plate model and hydrodynamic force is obtained by the proposed approach. The coupled natural frequencies are obtained from the relationship between kinetic energies of a wall including fluid and the potential energy of the wall. The theoretical result is compared with the three-dimensional finite element method. In order to verify the result, modal test was carried out for bottom/side plate of tank model by using impact hammer. It was found the fundamental natural frequency of bottom plate is lower than that of side plate of tank and theoretical result was in good agreement with that of commercial three-dimensional finite element program.