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Developing a prototype concurrent design tool for composite topside structures

NAVAL ENGINEERS JOURNAL 1997年第3期109卷 279-290页

作者： Dirlik, S Hambric, S Azarm, S Marquardt, M Hellman, A Bartlett, S Castelli, V Steve Dirlik:began his career at the Naval Surface Warfare Center Carderock Division in 1981 as an aerospace engineer co-op student. He completed his bachelor of science degree in aeropace and ocean engineering from Virginia Polytechnic Institute and State University in 1985 and his master of science degree in aerospace engineering from the University of Maryland in 1990. Mr. Dirlik recently completed a master of science program in applied physics at The Johns Hopins University and currently works in the Radar Cross Section and Target Physics Branch of the Signatures Directorate at the Naval Surface Warfare Center Corderoke Division. He has worked on Navy low observable programs since 1990. Stephen Hambric:is a research associate at the Applied Research Laboratory at The Pennsylvania State University. He received his B. S. and M.S. degree in mechanical engineering from Virginia Polytechnic Institute and State University and his D. Sc. in mechnical engineering from the George Washington University. He has worked on several computer aided multidiscikplinary design and optimization projects over the years including an automated propeller design system and a structural acoustic optimization capability. Dr. Shpour Azarm:is currently working as an associate professor with the Design and Manufacturing Group of the Department of Mechanical Engineering at the University of maryland at College Park. Dr Azarm's expertise is in the areas of optimization-based designed and concurrent design and optimization of multidisciplinary systems. He was a consultant at Black & Decker Corporation (summer 1996) and worked as a Navy senior summer faculty fellow (summer 1995) and a NASA summer faculty fellow (summer 1994). He was a visiting scientist at NASA Langley Research Center for Multidisciplinary Analysis and Applied Structural Optimzatiom at the University of Siegen in Germany (spring 1992) and the Design Institute of the Technical University of Denmark (summer 1990). Dr Azarm was an associate technical editor of the ASME Jour

A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent engineering of Layered Structures, provides designers with an immediate assessment of the impacts of their decisions on several disciplines which are important to the performance of a modern naval topside structure, including electromagnetic interference effects (EMI), radar cross section (RCS), structural integrity, cost, and weight. Preliminary analysis modules in each of these disciplines are integrated to operate from a common set of design variables and a common materials database. Performance in each discipline and an overall fitness function for the concept are then evaluated. A graphical user interface (GUI) is used to define requirements and to display the results from the technical analysis modules. Optimization techniques, including feasible sequential quadratic programming (FSQP) and exhaustive search are used to modify the design variables to satisfy all requirements simultaneously. The development of this tool, the technical modules, and their integration are discussed noting the decisions and compromises required to develop and integrate the modules into a prototype conceptual design tool.

关键词： Warships

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Hydroelastic considerations in ship panel design

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NAVAL ENGINEERS JOURNAL 1997年第5期109卷 61-66页

作者： McCormick, ME Bhattacharyya, R Mouring, SE Dr. Michael E. McCormick:is a research professor of civil engineering at The Johns Hopkins University. Before joining the Hopkins faculty in 1994 he was a professor of ocean engineering for twenty-five years at the U.S. Naval Academy. In addition he has held full-time faculty positions at Swarthmore College Trinity College (Hartford) and the Catholic University of America. He was also a hydrodynamicist at the David Taylor Model Basin for more than four years. Prof. McCormick received his undergraduate degree in mathematics and physics from AmericanUniversity a masters degree in applied mechanics and a Ph.D. in mechanical engineering from Catholic University a Ph.D. in civil engineering and a Sc.D. in engineering science from Trinity College in Dublin Ireland. He has over 100 publications including two books in the areas of ocean engineering wave mechanics and ocean wave energy conversion. He has also edited two books dealing with ocean engineering. In addition he is co-editor of both the journal Ocean Engineering and the Elsevier book series in ocean engineering. Dr. Rameswar Bhattacharyya:is professor of naval architecture at the U.S. Naval Academy where he has served for twenty-six years and adjunct professor of mechanical engineering at The Johns Hopkins University. Prior to joining the Naval Academy faculty he was a faculty member in the Department of Naval Architecture and Marine Engineering at the University of Michigan. His research experience includes ten years at both the Lubecker Flender-Werke and the Hamburg Ship Model Basin in Germany. His research has led to numerous publications including two books one in the area of ship dynamics and the other in the area of computer-aided ship design. Prof. Bhattacharyya received his undergraduate degree in naval architecture from the Indian Institute of Technology and his doctorate in engineering from the Technical University of Hanover Germany. In addition he holds an honorary doctorate from the University of Veracruz. With Prof. McCormick he co

Panels and all other structural components of surface ships and submarines vibrate when the vessel is underway. The vibratory motions are primarily excited by the power plant. At operational (design) speeds, panels vibrate in their fundamental modes and those associated with their higher harmonic frequencies. The panel motions have rather well-defined energy spectra, which depend on both the structural design, position of the panel and the rotational speed of the single or multiple power plants. The panel motions will interact with the vortices in the adjacent turbulent boundary layer. The interaction can result in either an increase in the frictional drag or a decrease. Because of this, the argument is made that the designs of the panels and their support systems should include considerations of this hydroelastic effect.

关键词： Naval architecture

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Finite Element Analysis of a Dissimilar Mixed Mode Bimaterial Interfacial Fracture Specimen

Finite Element Analysis of a Dissimilar Mixed Mode Bimateria...

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ASME 1996 International Mechanical engineering Congress and Exposition, IMECE 1996

作者： Zhang, Jinmiao Lu, Gui-Ying Kenner, Vernal H. Soboyejo, Wolé Department of Materials Science and Engineering The Ohio State University 2041 College Road ColumbusOH43210 United States Aerospace Engineering Applied Mechanics and Aviation The Ohio State University 155 West Woodruff Avenue ColumbusOH43210 United States

ISBN: (纸本)9780791815229

A finite element model of a dissimilar mixed mode bimaterial interfacial was generated using the commercial FEMAP software and analyzed using ABAQUS. Finite element techniques were used to estimate the strain energy release rates of interfacial cracks in a copper/moulding compound system. The finite element results are shown to be in good agreement with theoretical predictions of the strain energy release rate obtained from an analytical linear elastic fracture mechanics model. The finite element techniques were also used to estimate the loading conditions that are required to avoid contact between the crack surfaces under monotonic loading. © 1996 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： ABAQUS

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Fabrication of SiN films at low temperature by RF biased coaxial-line microwave plasma CVD

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS 1996年第11期79卷 58-65页

作者： Morita, Y Kato, I Nakajima, T School of Science and Engineering Waseda University Tokyo Japan Received a B.S. in 1992 from the Department of Electronics and Communication Waseda University. He is now enrolled in the Ph.D. program at the same university. He has been involved in research on microwave plasma CVD. He is a member of the Japanese Society of Applied Physics. Received the B.S. and Ph.D. degrees from the Department of Electronics and Communication Waseda University in 1967 and 1973 respectively. In 1973 he joined the faculty of Waseda University becoming an associate professor in 1978. He was Visiting Professor at Manitoba University Canada in 1979–1981. He has supervised research and participated in joint research with die Canadian National Research Council. He became a professor at Waseda University in 1993. He has been involved in research on microwave plasma CVD photonics lasers electronic materials evaluation technologies photonic materials opto-quantum electronics and semiconductor dun films. He is a member of die IEE of Japan die Japan Society of Applied Physics die TV Society die Japanese Vacuum Society and IEEE. Received die B.S. from die Department of Electronics and Communication Waseda University in 1994. He is now enrolled in die master's program at die same university. He has been involved in research on microwave plasma CVD. He is a member of die Japan Society of Applied Physics.

This paper discusses the influence of ion bombardment on the characteristics of SiN films. In this study, the double-tube coaxial-line microwave plasma CVD system, which is suitable for the investigation of ion bombardment, is used to deposit SiN films. The ion bombardment energy is varied by varying the RF bias at constant ion density, As the RF bias is increased, the film density increases and the hydrogen concentration decreases, but the dangling bond density increases. The increase in the film density and decrease of hydrogen concentration are caused by the increase in film surface temperature, while the increase of the dangling bond density is caused by bond breakage due to the N+ ion implantation. When the substrate temperature is 200 degrees C and the RF bias is -175 V, the film density is 3 g/cm(3) and the hydrogen concentration is 9 at.% because of the film surface heating effect of ion bombardment acid also due to substrate heating. Substrate heating at 200 degrees C suppresses the increase in the dangling bond density. It is also demonstrated that the film surface temperature is about 200 degrees C when RF bias is -70 similar to-80 V and the substrate is unheated by any heater.

关键词： microwave plasma CVD SiN film RF bias ion bombardment effect film surface hearing effect

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DEFORMATION-BEHAVIOR AND FAILURE MECHANISMS IN PARTICULATE-REINFORCED 6061-AL METAL-MATRIX COMPOSITES

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materials science AND engineering A-STRUCTURAL materials PROPERTIES MICROSTRUCTURE AND PROCESSING 1995年第1-2期202卷 63-75页

作者： KAPOOR, R VECCHIO, KS Materials Science Group Department of Applied Mechanics and Engineering Sciences University of California San Diego CA 92093 USA

The deformation behavior and failure mechanisms in 6061 Al alloy matrix particulate composites were examined via uniaxial tension and compression tests. The dependence of the deformation behavior on the matrix properties was studied by varying the heat treatment conditions (T4 and T6) of the matrix. The influence of the heat treatment condition on the deformation behavior of the composite was observed to be stronger than the influence of particle shape, size and volume fraction. In both tension and compression testing, composites in the T4 condition experience a larger degree of work-hardening as compared to the materials in the T6 condition. When subject to uniaxial tension, the deformation and failure behavior is strongly dependent on the relative strengths of the particles and matrix, and on the work-hardening behavior of the matrix, which is influenced by heat treatment condition. In compression, the particles merely act as obstacles to the flow of the matrix, whereas in tension they influence the failure mechanism of the composite.

关键词： DEFORMATION FAILURE MECHANISMS METAL-MATRIX COMPOSITES

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A DUALITY PRINCIPLE AND CORRESPONDENCE RELATIONS IN ELASTICITY

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INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES 1995年第3-4期32卷 467-472页

作者： NEMATNASSER, S NI, L Center of Excellence for Advanced Materials Department of Applied Mechanics and Engineering Science University of California San Diego La Jolla CA 92093 U.S.A.

The equilibrium equations for elasticity problems with field variables depending on two rectangular Cartesian coordinates, x(1) and x(2), reduce to sigma(j1,1), + sigma(j2,2) = 0, j = 1, 2, 3. These equations are satisfied if a vector potential phi is introduced for the stress components sigma(ij), such that sigma(j1) = partial derivative phi(j)/partial derivative x(2), and sigma(j2) = -partial derivative phi(j)/partial derivative x(1). In terms of the six-dimensional vector field eta = [u,phi](T), the basic elasticity equations reduce to partial derivative/partial derivative x(2)[u,phi](T) = N partial derivative/partial derivative x(1)[u,phi](T), where u is the displacement field and N is called the fundamental elasticity matrix, given by the elastic moduli of the solid. This formulation removes the distinction between the displacement vector field u, and the stress potential vector field phi. Indeed, these two vector fields are, in many respects, each other's dual, in the sense that the solution to a class of ''displacement problems'' also provides the solution of the corresponding dual ''force problems''. This duality principle is examined in terms of the known solutions of an edge dislocation and a concentrated line force. Then several correspondence relations are also pointed out and discussed. It is shown that the displacement (stress potential) field of a displacement (stress) boundary-value problem can be reduced to the corresponding stress potential (displacement) field by a simple parameter manipulation.

关键词： Elasticity

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Dai et al. Reply:

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Physical Review Letters 1995年第14期74卷 2837-2837页

作者： Chi-An Dai Benita J. Dair Kevin H. Dai Christopher K. Ober Edward J. Kramer Chung-Yuen Hui Lynn W. Jelinski Department of Materials Science and Engineering and theMaterials Science Center Cornell UniversityIthaca New York 14853 Department of Theoretical and Applied Mechanics andthe Materials Science Center Cornell UniversityIthaca New York 14853 Biotechnology Program and the College of EngineeringCornell University Ithaca New York 14853

A reply to the Comment by Jaan Noolandi and An-Chang Shi.

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Thermal Fatigue of MoSi 2 Particulate and Short Fiber Composites

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MRS Online Proceedings Library 1994年第1期350卷 189-194页

作者： M. T. Kush J. W. Holmes R. Gibala Department of Materials Science and Engineering The University of Michigan Ann Arbor USA Department of Mechanical Engineering and Applied Mechanics The University of Michigan Ann Arbor USA

Induction heating of disk shaped specimens was used to compare and contrast the thermal fatigue behavior of MoSi2 and MoSi2-based composites. Specimens were subjected to 5 s heating and cooling cycles between temperature limits of 700°C and 1200°C. The monolithic material and a MoSi2- 10 vol% TiC composite exhibited poor thermal shock resistance and could not be thermally cycled according to this temperature-time profile. A 30 vol% TiC composite exhibited much better thermal shock and thermal fatigue resistance as compared to the monolithic material, but exhibited undesirable oxidation. MoSi2-10 and 30 vol% SiC particulate composites exhibited excellent thermal shock and thermal fatigue resistance compared to that of the monolithic material. A MoSi2-10 vol% SiC whisker composite did not show improved thermal fatigue resistance due to the initial processing defects present in the material. The monolithic material and the 10 vol% TiC composite were also subjected to 30 s heating and cooling cycles between temperature limits of 700°C and 1200°C. Both of these materials exhibited better thermal fatigue resistance at this temperature-time profile, but the 10 vol% TiC composite also exhibited undesirable oxidation. The fatigue results are discussed with reference to the initial microstructure of the specimens and the stress-strain history of the specimens which was obtained by a thermoelastic finite element analysis.

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Atom Probe Microscopy and its Future

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MRS Online Proceedings Library 1994年第1期332卷 587-598页

作者： T. F. Kelly P. P. Camus D. J. Larson L. M. Holzman Materials Science Program University of Wisconsin Madison USA Department of Materials Science and Engineering University of Wisconsin Madison USA Applied Superconductivity Center University of Wisconsin Madison USA

Much of the current activity and excitement in materials science involves processing and understanding materials at the atomic scale. Accordingly, it is necessary for materials scientists to control and characterize materials at the atomic level. There are only a few microscopies that are capable of providing information about the structure of materials at the atomic level: the atom probe field ion microscope, the high resolution transmission electron microscope, and the scanning tunneling microscope. The three-dimensional atom probe (3DAP) determines the 3D location and elemental identity of each atom in a sample. It is the only technique that provides 3D information at the atomic scale. The origin and underlying concepts behind the 3DAP are described. Several examples of actual images from existing 3DAPs are shown with emphasis on nanometer-scale analysis. Current limitations of the technique and expected future developments in this form of microscopy are described. It is our opinion that 3D atomic-scale imaging will be an indispensable tool in materials science in the coming decades.

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LASER CLADDING REFURBISHMENT OF CATAPULT TROUGH COVERS

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NAVAL ENGINEERS JOURNAL 1993年第6期105卷 69-75页

作者： DENNEY, PE LOWRY, RW Paul E. Denney:has been involved with high-powered laser materials processing for over eight years. Mr. Denney received both his BS and MS degrees in metallurgy from MIT in 1980. He was employed for one year by CF&I Steel of Pueblo Colo. before joining the Naval Research Laboratory in Washington D.C. where he was involved with failure analyses and laser materials processing. From 1985 to 1988 Mr. Denney conducted laser materials processing at the Westinghouse Research and Development Center in Pittsburgh Pa. Since 1988 he has been at the Applied Research Laboratory at Pennsylvania State University (ARL Penn State) where he has assisted in the development of the laser metalworking technology transfer facility (in Johnstown Pa.) and the laser processing group within the ARL Penn State Manufacturing Science Department. Mr. Denney directs laser and other advanced thermal processing programs for the Navy Army and many private industrial sponsors. Robert W. Lowry:graduated from Virginia Polytechnic and State University with BS and MS degrees in metallurgical engineering in 1967. He has worked at the Naval Surface Warfare Center for 30 years and has been involved with laser process technology since 1979. Mr. Lowry has worked in fragmentation studies failure analysis materials testing and been associated with such Navy programs as Vertical Launch Standard Missile Guided Projectile and the In-Service Manufacturing Technology Advisory Group (MTAG) Metals Subcommittee. He has submitted two patent applications in laser processing and is current manager of NSWC's high power laser facility. Current emphasis is on laser welding for missile structures. Mr. Lowry has recently been selected as a participant in the Navy Science Advisory Program (NSAP) as a technical advisor at CinCLantFlt Norfolk for fleet maintenance.

A laser cladding process has been developed and is now in production for the cladding of new aircraft carrier catapult components. The Service Life Extension program (SLEP) Office of Naval Sea Systems Command (NavSea) suggested that this process be utilized for the refurbishment of catapult tracks. Early experiments were conducted by the Naval Surface Warfare Center in conjunction with the IIT Research Institute. The program was then transitioned to the applied Research Laboratory, Pennsylvania State University (ARL Penn State) under the sponsorship of the Naval Air Systems Command (NavAir)/Navy MANTECH program, thus providing an effective solution to a NavSea/NavAir interface hardware problem. ARL Penn State was responsible for the production and evaluation of six laser clad aircraft carrier catapult tracks as part of a program sponsored and funded by NavAir Code 5512. Six catapult tracks that had been taken out of service because of excessive wear were laser clad at the Westinghouse Electric Research and Development Center (Now ''science and Technology Center'') for ARL Penn State. The composition of the clads was Inconel 625, Stellite 6/Stainless Steel 304, and Ferrelium 255. The tracks were machined and installed on the USS Constellation. Wear measurements were taken for the laser clad tracks and standard tracks ahead and behind the clad tracks. After 7,161 launches, the tracks were removed and returned to ARL Penn State for evaluation. The evaluation indicated that impact damage was observed on one track. No additional defects related to operations were found. Wear data indicated that the wear rate for it was 25%-50% less than non-clad. The results indicated that rejectable tracks (and one piece trough covers) could be successfully laser clad for extended operating life at acceptable costs. With emphasis for the future on a more affordable Navy, the need for viable refurbishment processes will be necessary for extending life and performance for the 21st century

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