The fracture behavior of several short glass fiber reinforced thermoplastics has been studied. The fracture toughness of these materials may be related to local crack propagation mode, which is found to be highly rate...
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The fracture behavior of several short glass fiber reinforced thermoplastics has been studied. The fracture toughness of these materials may be related to local crack propagation mode, which is found to be highly rate dependent. At low test rates the crack growth in the reinforced polymers tend to follow a fiber avoidance mode, creating a greater area of new surfaces, which in conjunction with greater degree of interfacial debonding and fiber pullout friction leads to a higher fracture resistance. An increase in loading rate in general results in a more straight and flat crack path, as well as a lesser extent of fiber debonding and pullout. Therefore the fracture toughness is reduced although the frequency of fiber breakage is increased. The fracture behavior of these short fiber reinforced polymers appears to be dictated by the matrix properties when the loading rate is high.
From these calculations it is shown that if a deformation induced vacancy flux should occur as hypothesized, it will result in a Zn concentration differrence between the center of a dislocation cell and the dislocatio...
From these calculations it is shown that if a deformation induced vacancy flux should occur as hypothesized, it will result in a Zn concentration differrence between the center of a dislocation cell and the dislocation cell walls of at least 10 −3 atom fraction, or possibly more in cylically deformed CuZn alloy. The zinc concentration should decrease near the vacancy sinks and increase near the sources. Hence, if such concentration gradients can be shown to develop during steady state fatigue, they will provide evidence as to the dominant direction of vacancy flow during fatigue. Such measurements will also provide insight into the magnitude of the vacancy generation rate and should lend support to one of the theories mentioned in the introduction. Such measurements require concentration determinations at the sensitivity of 10 −4 over a spatial dimension approximately 1/10 of the cell size, or approximately 0.2 μm. A step counting energy dispersive x-ray technique such as available on modern electron microprobes with measurement of Cu and Zn peaks or the use of STEM with energy dispersive x-ray capability should provide the answers. We are in the process of developing collaborative efforts to carry out these experiments. These calculations also estimate the vacancy flux at the cell wall due to the creation of 1 ppm vacancies per second [7] during cyclic deformation as sufficient to generate one unit climb of every dislocation in the cell wall during 35 cycles under typical low cycle fatigue deformation conditions. The rapid dislocation rearrangement and recovery in the cell walls produced by this flux of vacancies lends additional credibility to the cell shuttling model.
作者：
PLATO, ARTIS I.GAMBREL, WILLIAM DAVIDArtis I. Plato:is Head of the Design Work Study/ Shipboard Manning/Human Factors Engineering Section
Systems Engineering and Analysis Branch Naval Ship Engineering Center (NAVSEC). He graduated from the City College of New York in 1956 receiving his Bachelor of Mechanical Engineering degree. Following this he started work at the New York Naval Shipyard in the Internal Combustion Engine and Cargo Elevator Section. During 1957 and 1958 he was called up for active duty with the U.S. Army Corps of Engineers and served in Europe with a Construction Engineer Battalion. After release from active duty he returned to the shipyard where he remained until 1961 when he transferred to the Naval Supply Research and Development Facility Bayonne New Jersey. Initially he was in charge of an Engineering Support Test Group and the drafting services for the whole Facility. Later he became a Project Engineer in the Food Services Facilities Branch with duties that included planning and designing new afloat and ashore messing facilities for the Navy. In 1966 he transferred to NAVSEC as a Project Engineer in the Design Work Study Section and in this capacity worked on selected projects and manning problems for new construction and also developed a computer program (Manpower Determination Model) that makes accurate crew predictions for feasibility studies. In 1969 he became Head of the Section. He has been active in the U.S. Army Reserve since his release from active duty and his duties have included command of an Engineer Company various Staff positions and his present assignment as Operations Officer for a Civil Affairs Group. He has completed the U. S. A rmy Corps of Engineers Career Course and the Civil Affairs Career Course and is presently enrolled in the U.S. Army Command and General Staff College non-resident course. Additionally he completed graduate studies at American University Washington D.C in 1972 receiving his MSTM degree in Technology of Management and is a member of ASE ASME CAA U. S. Naval Instit
The purpose of this paper is to discuss a system analysis technique called “Design Work Study”, that is used by the U.S. Navy for the development of improved ship control systems. The Design Work Study approach is o...
作者：
SONENSHEIN, RADM. NATHANUSNThe author graduated from the U.S. Naval Academy in the Class of 1938. His work has included instruction in Naval Construction and Marine Engineering at the Massachusetts Institute of Technology leading to a Master of Science degree in 1944 and the Advanced Management Program at Harvard Graduate School of Business in 1964. As an Engineering Duty Officer (EDO)
he has served in various Navy commands including the Mare Island Naval Shipyard the former New York Naval Shipyard the USS Philippine Sea (CVA-47) during the Korean War as Chief Engineer and CINCPACFLT and COMSERVPAC Staffs as Fleet and Force Maintenance Officer. Within the Naval Ship Systems Command and its predecessor BUSHIPS his duties have included Director of the Facilities Division Head of the Hull Design Branch Director of the Ship Design Division Assistant Chief for Design Shipbuilding and Fleet Maintenance and as Commander Naval Ship Systems Command from 1969 until 1972. Other duties have included an assignment as the Project Manager for the Navy's Fast Deployment Logistic Ship Project from 1965 to 1967 Deputy Chief of Naval Material for Logistic Support from 1967 to 1969 and Chairman of the Naval Material Command Shipbuilding Council which commenced upon completion of his tour as Commander NAVSHIPS in 1972. On 4 September 1973 he was appointed Director of the Defense Energy Task Group (DETG) and subsequently on 15 November 1973 as Director of Energy for the Department of Defense. A former President of ASNE from 1970 to 1971 he is currently Vice-President of the American Society of Naval Architects and Marine Engineers. In addition he is a member of the honorary engineering society Sigma Xi and listed among those in Who's Who in America.
作者：
SONENSHEIN, N.U. S. NAVYTHE AUTHOR: is a graduate of the United States Naval Academy
Class of 1938. His graduate work has included instruction in Naval Construction and Marine Engineering at Massachusetts Institute of Technology leading to a Master of Science degree in 1944 and the Advanced Management Program at the Harvard Graduate School of Business in 1964. As an Engineering Duty Officer he has served in various Naval commands including the Mare Island Naval Shipyard the New York Naval Shipyard and as Fleet and Force Maintenance Officer on the staffs of Commander in Chief and Commander Service Force U.S. Pacific Fleet. Within the Naval Ship System Command formerly the Bureau of Ships his duties have included Director of the Facilities Division Head of the Hull Design Branch Director of the Ship Design Division and Assistant Chief of the Bureau of Ships for Design Shipbuilding and Fleet Maintenance. He is a member of Sigma Xi ASNE and SNAME. From October 1965 to 31 July 1967 he served as Project Manager Fast Deployment Logistic Ship Project. As of 1 August 1967 he has assumed the duties of Deputy Chief of Naval Material for Logistic Support.
作者：
WILSON, TBUSN (RET)COMMANDER T. B. WILSON
JR. USN (RET) served as an enlisted man aboard USS SPROSTON (DD 577) and other Destroyer Forces Atlantic Fleet ships prior to his entrance into the U.S. Naval Academy in 1944. After graduating in 1948 he served on PHIBPAC ships until 1951 when he entered Webb Institute of Naval Architecture. He graduated from Webb with a Bachelor of Science Degree in Marine Engineering and a Master of Science Degree in Naval Architecture in 1953. He has served as Planning and Design Officer for the Supervisor of Shipbuilding in Jacksonville Florida was Assistant Material Officer on the Staff
Commander Mine Forces U.S. Pacific Fleet and as Docking Officer and Ship Superintendent Long Beach Naval Shipyard. He then served in the Engineering Department of the USS RANDOLPH (CVS 15) after which he reported to the Bureau of Ships where he worked as Aircraft Carrier Project Officer in the Contract Design Division. He was Industrial Officer at the David Taylor Model Basin prior to assuming duties as Fleet Maintenance Officer Staff Commander in Chief U.S. Naval Forces Europe. Prior to retiring on 1 January 1969 he served as Repair Officer U.S. Naval Support Activity Saigon. Since retirement he has been Manager of System Engineering and Senior Member of the Technical Staff for the LHA Program at Litton's Advanced Marine Technology Group and is currently Manager Engineering Design with HARCO Engineering the design division of Harbor Boat Building Company Terminal Island California.
作者：
Brebrick, R.F.Faculty Member
Material Science Program College of Engineering Marquetre University Milwaukee Wis. United States
The liquidus line for a compound A m B n (c) which has a narrow homogeneity range and whose Gibbs free energy of formation varies insignificantly with composition is investigated. It is shown that any fit of a liquidu...
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