The National Shipbuilding Research Program. Proceedings of the REAPS Technical Symposium. Paper No. 20: Application of the GIFTS-5 Minibased Graphics System for Ship Design and Analysis PDF Download

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 29

View

Book Description
Proceedings of the REAPS Technical Symposium. Paper No. 20: Application of the GIFTS-5 Minibased Graphics System for Ship Design and Analysis. The GIFTS finite element structural analysis system has been developed with the support of the Office of Naval Research, the U.S. Coast Guard, and members of the GIFTS Users Group (GUG). It is a graphics-oriented collection of programs, which operate on a standardized data base. The system is designed to fit in a relatively small core area, and is specifically suited to time sharing and mini-computer systems. It may be used as a stand-alone finite element package or as a pre- and postprocessor for other systems.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 9

View

Book Description
When the decision was made to proceed with the development of the Interactive Graphics version of the SPADES System, a list of requirements and goals was made. One of the major considerations was to have total interchangeability between the graphic and the batch mode of the System such that rework could be processed easily, whether the original work had been done through the 'CRT' or in batch. As much as we would like to think otherwise, experience has taught us that changes and revisions are an ever present way of life during the ship design and construction process. The requirement was also set that none of the SPADES management and control features would be compromised because of the graphic. In order for the graphic version to be a useful production tool, the user would have the capability of totally checking parts and/or burning tapes generated through the CRT without having to wait for a drafting machine drawing and/or computer printout. It was also decided that the user would have the capability of switching from one program to another directly from the tube without re-initializing any program at the central computer. The plans called for four CRTs to be on simultaneously, and for at least one batch SPADES program to be also running at the same time. This requirement caused the only major modification of the then existing SPADES System in order to allow different programs to read and write records from the same data base at the same time. By combining the use of virtual memory capability of the computer and judicious use of overlay, all the applicable programs have been linked together in one executable module.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12

View

Book Description
This session centered on the current capabilities of several commercially available graphics systems in parts nesting and computer aided shipyard drafting. Three representatives of graphics system vendors participated on a panel to answer questions from the audience concerning their products' capabilities and graphics systems in general. These representatives were Dr. Robert Cowen of Computervision Corporation. Robert N. Hickox of Adage, Inc. and Lou Melancon of Auto-Trol Corporation. In addition, a representative of the italian yard italcantieri S.p.A. was on hand to relate that yard's experience in the use of Adage equipment for interactive nesting. Of interactive nesting italcantieri, in response to questions from the floor, has seen a reduction in nesting labor as a result of using their system from between 20,00 to 24,000 man-hours per year. He further stated this effort represented the production of some 2500 nest tapes. On the topic of system reliability the vendors reported uptimes for their systems in excess of 95%. The cost of these systems was also questioned. Without a clear description of the application, number of users, etc. of such a system, the vendors were able to respond only that the costs ranged from around $100,000 for a single user drafting system on up. On the topic of computer aided design systems two members of the audience reported on the Navy's development efforts in this area. Two current applications cited in the Navy are a computer aided hull lines generation system employing interactive graphics and a graphics assisted ship's arrangements program.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 17

View

Book Description
The computer graphics technology is now developed far enough to be applicable in CAD systems for use in the shipbuilding industry. Computer graphics implies on-line access to the computer system, and will give the users a more direct contact with the computer assisted design process. Graphical presentation of the contents of the database will make the database more user-oriented.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 26

View

Book Description
The shipyards in this country have spent a sizable amount of money to modernize their methods of fabrication to increase construction. The shipbuilding industry is a labor intensive business based on small orders of ships that does not allow for total automation in the near term, if ever. One area of a shipyard that has minor or limited changes is the structural design office. The manual drafting of working drawings is basically the same as the methods used in the 1950's. A number of yards have restructured the working drawing to assembly type drawings. This is a major change assisting in the construction of the ship, but is still limited in scope. The present method does not allow for an orderly progression into the application of computers. The development of working drawings to assist construction is-poor and this stagnation has restricted the design office from converting drawings to computers. The problem stems from false economy values. The idea that a limited budget for the development of working drawings will increase the yard's profit margin is a false one. Every effort, or person hour, used in design should have a direct savings in production manhours. The goal of the designer's output should be a necessary and direct part of the construction program. Many design offices may not even realize that they are not only reducing costs, but are driving them up due to poor detailing. (A complete study of the working drawing process should be made objectively by design, production and planning people). This paper may give the basic outlines for consideration. Thomas P. Gallagher, Surface Ship Structures, Head, Research, Dynamic/Highedr Performance Craft Section, Phone 202-692-9107, Naval Ship Engineering Center.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 50

View

Book Description
Given the very minimum input of length, beam, draft, prismatic and midship section coefficients, LCE, LCF, and a deck at edge definition; HULGEN computes all of the initial parameters and control curves required to produce a body plan. This body plan is not the one desired, but provides a starting point for any variations the user wants to make. The SHIP HULL FORM GENERATOR (HULGEN) uses a piecewise polynomial development and representation of an early stage design ship's body plan. It was originally written for refresh. graphics scopes with light pens. Those earlier versions of the program, although done for light pen picks, operated in a way that made conversion to storage tube graphics very practical. The displays were changed very little and the interactive light pen picks were converted to keyboard entry menus. The user now types a menu option and/or data to proceed. HULGEN was developed specifically for the early stage design problem of developing many optional hulls rapidly. At this point in the design it is important to be able to determine whether the desired hull form can be developed from the gross dimensions and form coefficients available. Hull form generation is distinguished from hull lines fairing in that the output is a visually smooth body plan which meets the desired ship dimensional parameters. The various control curves and resulting body plan are mathematically smooth but not fair in the traditional sense.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 33

View

Book Description
The use of computers has made a tremendous impact on the ship design and the ship building processes in recent years. Designers utilize special programs to optimize their design according to economic and performance requirements. for a certain type of vessel in a certain type of service. From this iterative process, the optimum parameters are obtained and the preliminary design carried out.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

View

Book Description
The paper discusses a number of facets of Computer-Aided Ship Design and Construction (CASDAC) in which the writer has been involved. A brief history of computers in the Navy is given, some notes on the CASDAC project, the flavor of two recent programs, Navy planning and philosophy in detail design. and construction, some notes on the Computer-Aided Piping Design and Construction (CAPDAC) project, and finally some notes on the increasingly important role of computer science. The U.S. Navy has a long history in the use of computers in shipbuilding. In May 1944 the first computer came into operation at Harvard, the Automatic Sequence Controlled Calculator -- the Harvard Mark I. This was designed and constructed by Professor Howard Aiken -- at that time a Commander in the United States Navy. It was the Bureau of Ships which first sponsored the operation of this calculator and some of the first problems attacked originated from the Bureau. In 1952, the Applied Mathematics Laboratory was established at the now David W. Taylor Naval Ship Research and Development Center (DTNSRDC) to initiate computer service to the Navy. For this installation the Univac's 6th computer was installed in 1953. Early work included shaft vibrations, shell stiffening, propeller design, underwater sound intensities, pipe stress analysis, and nuclear reactor design. Within a year, this computer was operating around the clock. By 1958, clients included personnel from the naval shipyards processing programs associated with their ship construction program. By 1960 naval shipyards possessed their own computers and programs were in operation for tank capacity tables, hull deflection, voltage drop, shock mounts, sound isolation, mast calculations, weights and moments, propulsion shaft bearing reactions, pipe bend calculations and pipe stress analysis.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

View

Book Description
In the mid 1960's the Computer Aided Ship Design and Construction project office, located in the Naval Ship Engineering Center, was chartered to apply computer aiding techniques to all phases of the naval shipbuilding process. After the aerospace industry's success in developing a productive wiring data system and an in-depth NAVSEC sponsored study at three designated naval shipyards of the cabling/wiring flow process during installation design, it was determined that a similar system should be developed for naval ship design and production. Because there are significant differences between wiring an aircraft and wiring a ship, a direct conversion from one application to the other was ruled out. In 1965 the Westinghouse Electric Corporation was selected to develop a system of computer programs for processing the flow of electrical and electronic cabling/wiring information used in ship construction. This system was to address the entire process of installation design of equipment on board any Navy ship. This included, such functions as cable routing, hanger selection, penetration design, planning and estimating supporting documents and the equivalent of all the necessary wiring plans. The C/W System is now being implemented at Norfolk and Long Beach and is scheduled for implementation in the other naval shipyards. This system is the first of what the author hopes will be a large number of computer aided ship design and construction programs to be developed and implemented by the Naval Sea Systems Command. It is expected that by applying these systems deliberately and diligently in an integrated shipyard modernization program, the total benefits of electronic data processing can be obtained, thus producing a better ship faster and at a lower cost.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 27

View

Book Description
Several types of surface interpolation techniques exist which are defined over triangular or rectangular surface patches. They all have proven their usefulness in Computer Aided Design. This paper describes a first approach to a programming system that combines triangular and rectangular interpolation methods and applies them to a typical design problem in shipbuilding, the representation Of a ship hull. The system is designed such that it requires only those data which are available from a common shiplines graph and produces the output in the most general form, i.e. as a set of points (X, Y, Z(X, Y)) for the single patches. This output will then be processed in a post-processor fashion by some particular graphical or production device.