Parts Of Hull Research Articles

Impact of Dock Tanks Pumping Plan on Structural Loads of a Dock and a Ship

Abstract Positioning of a ship on a working platform above the waterline in order to repair and modernize the underwater hull parts requires changes from continuous support to point support. And as a result of such, the load of the ship structure is subject to changes as well. In extreme cases, the loads may exceed the allowable loads and cause damage to the hull structure. The paper presents the technical aspects of the ships docking process which may have an impact on safety. It also includes a discussion on procedures that reduce the risk of malfunction and failure.

Stability of the Structure of WE43 Cast Magnesium Alloy Welded Joints at Elevated Temperatures

The WE43 cast magnesium alloy is characterized by high development prospects due to its strength properties and maximum operating temperature of up to 250°C. It is used in the automotive and aircraft industries for engine, hull and gear parts. These are mainly individual or low-volume large-size casts, which in the casting process may display some defects in the form of misruns, shrinkage porosities and cracks. These defects are repaired with the application of welding technologies, which are also used to joint castings into structures and to repair castings after operation. The weld joint is an integral part of the structure. Therefore, it decides on the properties of the entire structure. It is important to get to know the microstructure and properties of magnesium alloy weld joints, and in particular those of the fusion weld. In this paper stability of the structure of WE43 cast magnesium alloy welded joint was researched.

The Comparative Evaluation of Amino Acid Profiles of the Dehulled and Hull Parts of Irvingia gabonensis Seeds

The Comparative Evaluation of Amino Acid Profiles of the Dehulled and Hull Parts of Irvingia gabonensis Seeds

무금형 다점 펀치를 사용한 선체외판의 분할 성형 가공 정보 계산 시스템 개발

As a forming method for curved hull plates more efficient than the flame bending, mechanical bending using multi point press forming and die-less forming is discussed in this paper. the mechanical forming is a flexible manufacturing system for automatically forming of hull parts. It is especially suited to varied curved parts. This paper discusses a multiple point pressing machine composed of a pair of reconfigurable punches in order to achieve the rapid forming of curved hull plates using division forming and presents how forming information is obtained from the given design surface. Although the mechanical forming can be efficient in the metal forming, spring back after pressing is a phenomenon which must be carefully considered when quantifying the process variables. If the spring back is not accurately controlled, the fabricated shell plate cannot meet assembly tolerance. This paper describes the principles to calculate the proper stroke of each punch at the divided areas. the strokes are determined by an iterative process of sequential pressing and spring back compensation from an unfolded flat shape to its given design surface. FEA(finite element analysis) is used to simulate the spring back of the plate and the IDA(iterative displacement adjustment) method adjusts the offset of pressing punches from the deformation results and the design surface. The shape deviations of two surfaces due to spring back are compensated by integrated system using FEA and IDA method. For the practical application, It is aimed to develop an integrated system that can automatically perform the compensation process and calculate strokes of punches of the double sides' reconfigurable multiple-press machine and some experimental results obtained with mechanical bending are presented.

Book Review of Sacred and Secular: Ancient Egyptian Ships and Boats, by Cheryl A. Ward

The Nile was the primary transport route of ancient Egypt, and watercraft played a key role at all levels of Egyptian society. Testifying to its importance are thousands of surviving boat images and models informing us about the appearance of Egyptian ships and boats, and texts telling us about shipbuilding materials, ship construction, names of hull parts, ship types, the uses of ships, tonnages, and voyages. Much of this material has been studied and published (B. Landström, Ships of the Pharaohs [New York 1970]; A. Göttlicher and W.

As-Built Product Modeling and Reverse Engineering in Shipbuilding Through Combined Digital Photogrammetry and CAD/CAM Technology

Ship repair, as a technological "lesser brother" of shipbuilding, still contains major elements of manual labor. In the past years, ship repair and the conversion of ships and offshore structures came to rely increasingly on modern computer-aided design and manufacturing (CAD and CAM) information systems for speedy generation of the required engineering information. An often-encountered problem is the lack of product information in electronic form or in any other form. Such information is needed for engineering of new parts for damaged or converted ships and platforms. In such cases one needs to build the virtual product model from the existing as-built object up to an engineering-detail level; hence, the terms "as-built modeling" and "reverse engineering." The paper presents the results of a multiyear project with the code name AMORES, which focuses on improving lead time and economic efficiency in ship and offshore platform repair and conversion in the Netherlands. Existing and newly developed photogrammetric measuring techniques were used to generate as-built models of double curved three-dimensional surfaces of ships and platforms. These were fed into standard CAD/CAM systems to engineer and manufacture new ship hull or platform parts to replace damaged areas. The main advantages of the new method are savings in lead time (measurements, engineering) and the replacing of costly manual labor by modern digital photogrammetry. The paper will focus on the new developments, the experienced difficulties, and the advantages of this new technique in ship repair.

Development of a computer-aided process planning system based on a knowledge base

Process planning for a hull structure defines the assembly sequence of the hull block. Although this activity is very important because the working strategy defines the production costs, to date it has been done manually. To raise the efficiency of this process, we developed a practical computer-aided process planning system. It has been developed using deliverables obtained from advanced computer integrated manufacturing system (CIM; ACIM) for shipbuilding projects sponsored by the Ship and Ocean Foundation (SOF). The system has a knowledge base which contains the know-how of skilled designers as well as design practices, and allows the assembly sequence of hull parts and intermediate products to be defined automatically. The system has been integrated with the shipyard CAD system MATES, and put to practical use.

Development of computer aided process planning system based on knowledge base

Practical computer aided process planning system has been developed by use of deliverables obtained from Advanced CIM (ACIM) for shipbuilding project sponsored by Ship and Ocean Foundation (SOF). The system has a knowledge-base which contains skilled designers' know-how as well as design practices and enables to define assembly sequence of hull parts and intermediate products automatically. The system has been integrated with shipyard CAD system MATES and put into practical use.

Structures Strength Verification Of 40,000 DWTDouble Hull Product Tanker.

The present work outlines structural strength verification procedures used for construction of double skin 40,000 DWT product tanker being built in Szczecin Shipyard S.A. The verification has been based on following computational procedures required by Lloyd's Register Classification Society and Owner's: 1. Procedure ' ShipRight Structural Design Assessment' [ 1 ]: • Analysis of hull cargo part strength using finite element method, • Local analysis of hull parts strength. • Analysis of cargo tanks strength under stresses caused by liquids sloshing in partially filled tanks ('ShipRight Sloshing Loads and Scantling Assessment' [2]). 2. Procedure 'ShipRight Fatigue Design Assessment' [3]. 1. General description of the hull. Principal dimensions of vessel are the following : Length over all 183.0 m Length between perpendiculars 172.4 m Breadth 32.2 m Height 17.6 m Draught 12.0m Speed 14.5 kn. Transactions on the Built Environment vol 24, © 1997 WIT Press, www.witpress.com, ISSN 1743-3509