Designing the Future DDG 51 Class Computer Aided Design

Author(s):  
Joanne J. Ouillette

Abstract The DDG 51 Class of AEGIS guided missile destroyers is the Navy’s premier surface combatant. Named for famed World War II hero. Admiral Arleigh Burke, these ships represent state-of-the-art technology. This 504 foot, 8,300 ton destroyer has been designed with improved seakeeping and survivability characteristics and carries the sophisticated AEGIS Weapon System. Derived from the Greek word meaning “shield”, AEGIS ships are the “shield of the fleet”. The Navy has commissioned the first two ships of the class. They have performed beyond expectation in rigorous at-sea trials designed to fully test combat capability. The DDG 51 Class ships are replacing retiring fleet assets. In a decreasing Department of Defense (DoD) budget environment, however, acquisition costs must be reduced to continue to build capable warships. The Navy’s Destroyer Program Office is pursuing the implementation of Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) technology to reduce costs without reducing ship’s capability. Under Navy direction, the ship construction yards, Bath Iron Works and Ingalls Shipbuilding, are aggressively pursuing the transition to CAD-based design, construction, and life cycle support This effort also involves General Electric, the Combat System Engineering Agent. Building a three dimensional (3D) computer model of the ship prior to construction will facilitate the identification and resolution of interferences and interface problems that would otherwise go undetected until actual ship construction. This 3D database contains geometry and design data to support system design. Accurate construction drawings, fabrication sketches, and Numerical Control (NC) data can be extracted directly from the database to support construction at each shipyard. At completion of construction, a model representing the “as built” configuration will be provided as a lifetime support tool for each ship’s projected 40 year life. The transition to CAD-based design and construction has applied fundamental concepts of the DoD’s Computer Aided Acquisition and Logistic Support (CALS) initiative. In addition to creating a 3D database representing ship design, the shipyards have developed a neutral file translator to exchange this data between Computervision and Calma CAD systems in operation at Bath Iron Works and Ingalls Shipbuilding respectively. This object oriented transfer capability ensures data is shared rather than duplicated. The CALS concepts of concurrent engineering and computer aided engineering analysis are being applied to design an upgrade to the ship that features the addition of a helicopter hanger. The CAD models are used as an electronic baseline from which to assess proposed modifications. Optimizing the design before the first piece of steel is cut will reduce construction costs and improve the quality of the ship.

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.


Author(s):  
L Q Tang ◽  
D N Moreton

The timing scroll is an important feeding mechanism on packaging lines. As packaging line speeds have increased and the shape of containers has become more diverse, the techniques used for the design and manufacture of such timing scrolls have become critical for successful packaging line performance. Since 1980, various techniques have evolved to improve scroll design, manufacture and the associated line performance. In recent years, as CAD (computer aided design), CAM (computer aided manufacture) and CNC (computer numerical control) techniques have evolved, scroll design and manufacturing techniques began to be linked with computer techniques. In this paper, a scroll design and manufacturing package is presented which can be run on a minicomputer, such as a μ-VAX on an IBM PC clone. This scroll package can produce a timing scroll for any type of container with a correct pocket shape and good dynamic characteristic. Tests using carefully chosen containers have been made using this package and the results indicate that the scrolls obtained by this package have the correct pocket shape and good line performance. However, the design of a good pick-up geometry for some container shapes remains a problem.


2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771038 ◽  
Author(s):  
Isad Saric ◽  
Adil Muminovic ◽  
Mirsad Colic ◽  
Senad Rahimic

This article presents architecture of integrated intelligent computer-aided design system for designing mechanical power-transmitting mechanisms (IICADkmps). The system has been developed in C# program environment with the aim of automatising the design process. This article presents a modern, automated approach to design. Developed kmps modules for calculation of geometrical and design characteristics of mechanical power-transmitting mechanisms are described. Three-dimensional geometrical parameter modelling of mechanical power-transmitting mechanisms was performed in the computer-aided design/computer-aided manufacturing/computer-aided engineering system CATIA V5. The connection between kmps calculation modules and CATIA V5 modelling system was established through initial three-dimensional models – templates. The outputs from the developed IICADkmps system generated final three-dimensional virtual models of mechanical power-transmitting mechanisms. Testing of the developed IICADkmps system was performed on friction, belt, cogged (spur and bevel gears) and chain transmitting mechanisms. Also, connection of the developed IICADkmps system with a device for rapid prototyping and computer numerical control machines was made for the purpose of additional testing and verification of practical use. Physical prototypes of designed characteristic elements of mechanical power-transmitting mechanisms were manufactured. The selected test three-dimensional virtual prototypes, obtained as an output from the developed IICADkmps system, were manufactured on the device for rapid prototyping (three-dimensional colour printer Spectrum Z510) and computer numerical control machines. Finally, at the end of the article, conclusions and suggested possible directions of further research, based on theoretical and practical research results, are presented.


2020 ◽  
Vol 3 (2) ◽  
pp. 31-32
Author(s):  
Paul Brian S. Mendez ◽  
Rizalie N.E. Mibato

Dentistry has evolved from its origin to the present day, becoming almost entirely digitized and supervised. The digitalized dental laboratory saves time due to computer-aided design and computer-aided manufacture (CAD/CAM) technology, which will capture and display clients' tooth or teeth and gums on a 3D image on a computer screen sent to the lab.  It enables a dental lab technician to work faster and get the perfect design of the digital dental restoration. The main advantage of digitalization includes faster and improved efficiency on the turn-around time of devices, like crowns and bridges, and improved accuracy of procedures and manufactured gadgets. Digitalization Dental Laboratory (DDL) is the first to offer a digital dental lab in the city of Bacolod. The service allows laboratories to design the prosthesis digitally from in-house CAD software and email the design data provider or download the data file into a proprietary web host or server. The lab will cater to the digital needs of dental patients of the Multi-Specialty Dental Center (a sister company of DDL) and other dental clients.


Author(s):  
Antor Mahamudul Hashan ◽  
Abdullah Haidari ◽  
Srishti Saha ◽  
Titas Paul

Due to the rapid development of technology, the use of numerically controlled machines in the industry is increasing. The main idea behind this paper is computer-aided design (CAD) based low-cost computer numerical control 2D drawing robot that can accurately draw complex circuits, diagrams, logos, etc. The system is created using open-source hardware and software, which makes it available at a low cost. The open-source LibreCAD application has been used for computer-aided design. Geometric data of a CAD model is converted to coordinate points using the python-based F-Engrave application. This system uses the Arduino UNO board as a signal generator of the universal g-code sender without compromising the performance. The proposed drawing robot is designed as a low-cost robot for educational purposes and aims to increase the student's interest in robotics and computer-aided design (CAD) skills to the next level. The drawing robot structure has been developed, and it meets the requirements of low cost with satisfactory experimental results.


Author(s):  
Tahir Abbas Jauhar ◽  
Soonhung Han ◽  
Soonjo Kwon

Abstract Computer-aided design, engineering, and manufacturing (CAx) have improved product design and development. The associativity of revised design in native files for downstream applications, assembly design, finite element analysis, and numerical control (NC) manufacturing has been supported by homogeneous CAx systems. However, heterogeneous CAx environments have issues when neutral models are revised and re-imported because the required identification information is missing. This results in a problem of the associativity of neutral models. In this study, different computer-aided design (CAD) applications have been analyzed with respect to their capabilities for import and export of neutral models with identification information. A tool has been selected to demonstrate the key findings. Moreover, future directions have been discussed to solve associativity issues in design re-import based on neutral models.


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