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J. D. Stachiw - One of the best experts on this subject based on the ideXlab platform.
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Structural performance of cylindrical Pressure Housings of different ceramic compositions under external Pressure loading. Part 3. Sintered reaction bonded silicon nitride ceramic. Final report
1994Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Ten 12-inch-OD by 18-inch-long reaction-bonded sintered silicon-nitride cylinders were fabricated, assembled, and Pressure tested to determine their suitability for use as external Pressure-resistant Housings for underwater applications. The material, designated PSX Si3N4, is made by CERCOM, Inc. (Vista, CA) by a proprietary process. The primary advantages of this material are high compressive strength, high elastic modulus, high fracture toughness, and low specific gravity. Pressure test results are presented along with strain gage data and cyclic fatigue life data. Conclusions regarding the suitability of the material for application to Pressure Housings for underwater applications are presented along with a comparison to WESGO's AL-600 96-percent alumina ceramic, which was chosen as the base of comparison for various advanced materials being evaluated under the same program. Recommendations for design implementation, nondestructive inspection, and further research are made. Ceramics, External Pressure Housing, Ocean engineering.
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Structural Performance of Cylindrical Housings of Different Ceramic Compositions Under External Pressure Loading. Part 3. Sintered Reaction Bonded Silicon Nitride Ceramic
1994Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Abstract : Ten 12-inch-OD by 18-inch-long reaction-bonded sintered silicon- nitride cylinders were fabricated, assembled, and Pressure tested to determine their suitability for use as external Pressure-resistant Housings for underwater applications. The material, designated PSX Si3N4, is made by CERCOM, Inc. (Vista, CA) by a proprietary process. The primary advantages of this material are high compressive strength, high elastic modulus, high fracture toughness, and low specific gravity. Pressure test results are presented along with strain gage data and cyclic fatigue life data. Conclusions regarding the suitability of the material for application to Pressure Housings for underwater applications are presented along with a comparison to WESGO's AL-600 96-percent alumina ceramic, which was chosen as the base of comparison for various advanced materials being evaluated under the same program. Recommendations for design implementation, nondestructive inspection, and further research are made. Ceramics, External Pressure Housing, Ocean engineering
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Evaluation of Alumina Ceramic Housings for Deep Submergence Service. Fifth Generation Housings. Part 1
1994Co-Authors: R. P. Johnson, R. R. Kurkchubasche, J. D. StachiwAbstract:Abstract : An unmanned undersea vehicle external Pressure Housing was designed for ocean depths of 20,000 feet (9,000 psi) using 96-percent alumina ceramic for the major hull components. The Pressure Housing assembly, with an outside diameter of 36 inches and an overall length of 91 inches, consists of two alumina cylindrical bays joined by a central stiffening titanium joint ring with forward and aft alumina hemispherical end closures. The exterior of the Housing is protected with a spectra fiber reinforced epoxy composite fairing. The alumina-ceramic components of the Housing assembly successfully withstood proof testing to 10,000 psi (1.1 times the design operating Pressure). The forward and aft head end closures also completed 500 cycles to 9,000 psi without catastrophic failure. The 26-inch diameter Housing assembly has a dry weight of 876 pounds and displaces 1,796 pounds when submerged in sea water, resulting in a net lift of 620 pounds. The net lift generated by the alumina ceramic Housing assembly is approximately three times greater than the net lift that would be achieved by an equivalent rib-stiffened titanium Housing assembly designed to the same operational requirements
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Effect of Different Axial Bearing Supports on the Fatigue Life of Ceramic Pressure Housings
1993Co-Authors: R. P. Johnson, R. R. Kurkchubasche, J. D. StachiwAbstract:Abstract : The fatigue life of underwater Pressure Housings composed of ceramic hull components assembled with epoxy-bonded metallic joint rings is dependent upon a number of parameters. The techniques used for bonding joint rings to the ceramic bearing surfaces is one such parameter that will affect the fatigue performance of Pressure Housings subjected to external Pressure cycles. This report summarizes recent research aimed at identifying metallic joint-ring bonding methods that improve the cyclic life of ceramic Pressure-Housing assemblies. Several joining methods based on using an interlayer of various gasket materials as an axial bearing support between the ceramic hull and the metallic joint ring have been shown to improve the structural performance of ceramic Pressure-Housing assemblies. Three of the most promising methods identified are a thin intermediate layer of epoxy between the bearing surfaces of the joint ring and the ceramic hull, a graphite fiber-reinforced thermoplastic composite gasket bonded to the bearing surface of the ceramic hull, and a ceramic ring bonded between the bearing surface of the metallic joint ring and the ceramic hull. Based on these findings, four alumina-ceramic cylinders were assembled using various axial bearing support techniques, Pressure cycled, and nondestructively evaluated to determine the extent of fatigue cracking that occurred during testing. While all four ceramic cylinders survived the external Pressure cycling intact, the use of a thin layer of epoxy adjacent to the bearing surface of the ceramic cylinder was found to induce the least amount of fatigue damage in the ceramic hull bearing surface region.
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Evaluation of Nondestructive Inspection Techniques for Quality Control of Alumina-Ceramic Housing Components
1993Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Abstract : Alumina-ceramic Pressure Housings have been shown to be feasible and cost-effective alternatives to Housings made from more traditional materials such as steel, titanium, or aluminum. The high specific compressive strength, and high specific elastic modulus of alumina ceramic allow engineers to design Pressure Housings having weight-to-displacement ratios lower than 0.60 for a service depth of 20,000 feet while remaining neutrally buoyant. Titanium Housings designed to the same requirements have weight-to-displacement ratios in excess of 0.85. Although the difference may, at first glance, seem negligible, it accounts for a tripling of the Housing payload weight capacity when alumina ceramic is substituted for titanium. The transition of alumina-ceramic Pressure Housing components from the developmental stage to the operational environment brings on the requirement for the capability of nondestructively inspecting these components for gross fabrication flaws and for in-service damage which may have occurred. Various radiographic and ultrasonic inspection methods are evaluated and compared based on their ability to detect defects, determine defect location, and characterize defect size and shape in large alumina-ceramic components used for deep submergence Pressure Housing applications. Recommendations based on the findings of the study are made for the nondestructive inspection of alumina-ceramic components.
P. Obradovic - One of the best experts on this subject based on the ideXlab platform.
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Design Process for Pressure Housing of Power Systems
Journal of Engineering Design, 1998Co-Authors: Milosav Ognjanović, P. ObradovicAbstract:Summary The design process of any technical system is based on well-elaborated procedures which lead, step by step, from the idea to the final product. For highly specialized products, such as power systems, this procedure contains some specific details \[1]. There are certain unique operations and activities, with specific constraints, leading to the result of a design process. In this paper the design process of power systems is presented as a set of appropriate models which make possible the evolution of these systems by linked software procedures and reflect themselves on the design process too. Apart from that, they represent the example of transformation of the design process into a form suitable for realization by software systems.
R. R. Kurkchubasche - One of the best experts on this subject based on the ideXlab platform.
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Structural performance of cylindrical Pressure Housings of different ceramic compositions under external Pressure loading. Part 3. Sintered reaction bonded silicon nitride ceramic. Final report
1994Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Ten 12-inch-OD by 18-inch-long reaction-bonded sintered silicon-nitride cylinders were fabricated, assembled, and Pressure tested to determine their suitability for use as external Pressure-resistant Housings for underwater applications. The material, designated PSX Si3N4, is made by CERCOM, Inc. (Vista, CA) by a proprietary process. The primary advantages of this material are high compressive strength, high elastic modulus, high fracture toughness, and low specific gravity. Pressure test results are presented along with strain gage data and cyclic fatigue life data. Conclusions regarding the suitability of the material for application to Pressure Housings for underwater applications are presented along with a comparison to WESGO's AL-600 96-percent alumina ceramic, which was chosen as the base of comparison for various advanced materials being evaluated under the same program. Recommendations for design implementation, nondestructive inspection, and further research are made. Ceramics, External Pressure Housing, Ocean engineering.
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Structural Performance of Cylindrical Housings of Different Ceramic Compositions Under External Pressure Loading. Part 3. Sintered Reaction Bonded Silicon Nitride Ceramic
1994Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Abstract : Ten 12-inch-OD by 18-inch-long reaction-bonded sintered silicon- nitride cylinders were fabricated, assembled, and Pressure tested to determine their suitability for use as external Pressure-resistant Housings for underwater applications. The material, designated PSX Si3N4, is made by CERCOM, Inc. (Vista, CA) by a proprietary process. The primary advantages of this material are high compressive strength, high elastic modulus, high fracture toughness, and low specific gravity. Pressure test results are presented along with strain gage data and cyclic fatigue life data. Conclusions regarding the suitability of the material for application to Pressure Housings for underwater applications are presented along with a comparison to WESGO's AL-600 96-percent alumina ceramic, which was chosen as the base of comparison for various advanced materials being evaluated under the same program. Recommendations for design implementation, nondestructive inspection, and further research are made. Ceramics, External Pressure Housing, Ocean engineering
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Evaluation of Alumina Ceramic Housings for Deep Submergence Service. Fifth Generation Housings. Part 1
1994Co-Authors: R. P. Johnson, R. R. Kurkchubasche, J. D. StachiwAbstract:Abstract : An unmanned undersea vehicle external Pressure Housing was designed for ocean depths of 20,000 feet (9,000 psi) using 96-percent alumina ceramic for the major hull components. The Pressure Housing assembly, with an outside diameter of 36 inches and an overall length of 91 inches, consists of two alumina cylindrical bays joined by a central stiffening titanium joint ring with forward and aft alumina hemispherical end closures. The exterior of the Housing is protected with a spectra fiber reinforced epoxy composite fairing. The alumina-ceramic components of the Housing assembly successfully withstood proof testing to 10,000 psi (1.1 times the design operating Pressure). The forward and aft head end closures also completed 500 cycles to 9,000 psi without catastrophic failure. The 26-inch diameter Housing assembly has a dry weight of 876 pounds and displaces 1,796 pounds when submerged in sea water, resulting in a net lift of 620 pounds. The net lift generated by the alumina ceramic Housing assembly is approximately three times greater than the net lift that would be achieved by an equivalent rib-stiffened titanium Housing assembly designed to the same operational requirements
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Effect of Different Axial Bearing Supports on the Fatigue Life of Ceramic Pressure Housings
1993Co-Authors: R. P. Johnson, R. R. Kurkchubasche, J. D. StachiwAbstract:Abstract : The fatigue life of underwater Pressure Housings composed of ceramic hull components assembled with epoxy-bonded metallic joint rings is dependent upon a number of parameters. The techniques used for bonding joint rings to the ceramic bearing surfaces is one such parameter that will affect the fatigue performance of Pressure Housings subjected to external Pressure cycles. This report summarizes recent research aimed at identifying metallic joint-ring bonding methods that improve the cyclic life of ceramic Pressure-Housing assemblies. Several joining methods based on using an interlayer of various gasket materials as an axial bearing support between the ceramic hull and the metallic joint ring have been shown to improve the structural performance of ceramic Pressure-Housing assemblies. Three of the most promising methods identified are a thin intermediate layer of epoxy between the bearing surfaces of the joint ring and the ceramic hull, a graphite fiber-reinforced thermoplastic composite gasket bonded to the bearing surface of the ceramic hull, and a ceramic ring bonded between the bearing surface of the metallic joint ring and the ceramic hull. Based on these findings, four alumina-ceramic cylinders were assembled using various axial bearing support techniques, Pressure cycled, and nondestructively evaluated to determine the extent of fatigue cracking that occurred during testing. While all four ceramic cylinders survived the external Pressure cycling intact, the use of a thin layer of epoxy adjacent to the bearing surface of the ceramic cylinder was found to induce the least amount of fatigue damage in the ceramic hull bearing surface region.
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Evaluation of Nondestructive Inspection Techniques for Quality Control of Alumina-Ceramic Housing Components
1993Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Abstract : Alumina-ceramic Pressure Housings have been shown to be feasible and cost-effective alternatives to Housings made from more traditional materials such as steel, titanium, or aluminum. The high specific compressive strength, and high specific elastic modulus of alumina ceramic allow engineers to design Pressure Housings having weight-to-displacement ratios lower than 0.60 for a service depth of 20,000 feet while remaining neutrally buoyant. Titanium Housings designed to the same requirements have weight-to-displacement ratios in excess of 0.85. Although the difference may, at first glance, seem negligible, it accounts for a tripling of the Housing payload weight capacity when alumina ceramic is substituted for titanium. The transition of alumina-ceramic Pressure Housing components from the developmental stage to the operational environment brings on the requirement for the capability of nondestructively inspecting these components for gross fabrication flaws and for in-service damage which may have occurred. Various radiographic and ultrasonic inspection methods are evaluated and compared based on their ability to detect defects, determine defect location, and characterize defect size and shape in large alumina-ceramic components used for deep submergence Pressure Housing applications. Recommendations based on the findings of the study are made for the nondestructive inspection of alumina-ceramic components.
R. P. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Structural performance of cylindrical Pressure Housings of different ceramic compositions under external Pressure loading. Part 3. Sintered reaction bonded silicon nitride ceramic. Final report
1994Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Ten 12-inch-OD by 18-inch-long reaction-bonded sintered silicon-nitride cylinders were fabricated, assembled, and Pressure tested to determine their suitability for use as external Pressure-resistant Housings for underwater applications. The material, designated PSX Si3N4, is made by CERCOM, Inc. (Vista, CA) by a proprietary process. The primary advantages of this material are high compressive strength, high elastic modulus, high fracture toughness, and low specific gravity. Pressure test results are presented along with strain gage data and cyclic fatigue life data. Conclusions regarding the suitability of the material for application to Pressure Housings for underwater applications are presented along with a comparison to WESGO's AL-600 96-percent alumina ceramic, which was chosen as the base of comparison for various advanced materials being evaluated under the same program. Recommendations for design implementation, nondestructive inspection, and further research are made. Ceramics, External Pressure Housing, Ocean engineering.
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Structural Performance of Cylindrical Housings of Different Ceramic Compositions Under External Pressure Loading. Part 3. Sintered Reaction Bonded Silicon Nitride Ceramic
1994Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Abstract : Ten 12-inch-OD by 18-inch-long reaction-bonded sintered silicon- nitride cylinders were fabricated, assembled, and Pressure tested to determine their suitability for use as external Pressure-resistant Housings for underwater applications. The material, designated PSX Si3N4, is made by CERCOM, Inc. (Vista, CA) by a proprietary process. The primary advantages of this material are high compressive strength, high elastic modulus, high fracture toughness, and low specific gravity. Pressure test results are presented along with strain gage data and cyclic fatigue life data. Conclusions regarding the suitability of the material for application to Pressure Housings for underwater applications are presented along with a comparison to WESGO's AL-600 96-percent alumina ceramic, which was chosen as the base of comparison for various advanced materials being evaluated under the same program. Recommendations for design implementation, nondestructive inspection, and further research are made. Ceramics, External Pressure Housing, Ocean engineering
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Evaluation of Alumina Ceramic Housings for Deep Submergence Service. Fifth Generation Housings. Part 1
1994Co-Authors: R. P. Johnson, R. R. Kurkchubasche, J. D. StachiwAbstract:Abstract : An unmanned undersea vehicle external Pressure Housing was designed for ocean depths of 20,000 feet (9,000 psi) using 96-percent alumina ceramic for the major hull components. The Pressure Housing assembly, with an outside diameter of 36 inches and an overall length of 91 inches, consists of two alumina cylindrical bays joined by a central stiffening titanium joint ring with forward and aft alumina hemispherical end closures. The exterior of the Housing is protected with a spectra fiber reinforced epoxy composite fairing. The alumina-ceramic components of the Housing assembly successfully withstood proof testing to 10,000 psi (1.1 times the design operating Pressure). The forward and aft head end closures also completed 500 cycles to 9,000 psi without catastrophic failure. The 26-inch diameter Housing assembly has a dry weight of 876 pounds and displaces 1,796 pounds when submerged in sea water, resulting in a net lift of 620 pounds. The net lift generated by the alumina ceramic Housing assembly is approximately three times greater than the net lift that would be achieved by an equivalent rib-stiffened titanium Housing assembly designed to the same operational requirements
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Effect of Different Axial Bearing Supports on the Fatigue Life of Ceramic Pressure Housings
1993Co-Authors: R. P. Johnson, R. R. Kurkchubasche, J. D. StachiwAbstract:Abstract : The fatigue life of underwater Pressure Housings composed of ceramic hull components assembled with epoxy-bonded metallic joint rings is dependent upon a number of parameters. The techniques used for bonding joint rings to the ceramic bearing surfaces is one such parameter that will affect the fatigue performance of Pressure Housings subjected to external Pressure cycles. This report summarizes recent research aimed at identifying metallic joint-ring bonding methods that improve the cyclic life of ceramic Pressure-Housing assemblies. Several joining methods based on using an interlayer of various gasket materials as an axial bearing support between the ceramic hull and the metallic joint ring have been shown to improve the structural performance of ceramic Pressure-Housing assemblies. Three of the most promising methods identified are a thin intermediate layer of epoxy between the bearing surfaces of the joint ring and the ceramic hull, a graphite fiber-reinforced thermoplastic composite gasket bonded to the bearing surface of the ceramic hull, and a ceramic ring bonded between the bearing surface of the metallic joint ring and the ceramic hull. Based on these findings, four alumina-ceramic cylinders were assembled using various axial bearing support techniques, Pressure cycled, and nondestructively evaluated to determine the extent of fatigue cracking that occurred during testing. While all four ceramic cylinders survived the external Pressure cycling intact, the use of a thin layer of epoxy adjacent to the bearing surface of the ceramic cylinder was found to induce the least amount of fatigue damage in the ceramic hull bearing surface region.
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Evaluation of Nondestructive Inspection Techniques for Quality Control of Alumina-Ceramic Housing Components
1993Co-Authors: R. R. Kurkchubasche, R. P. Johnson, J. D. StachiwAbstract:Abstract : Alumina-ceramic Pressure Housings have been shown to be feasible and cost-effective alternatives to Housings made from more traditional materials such as steel, titanium, or aluminum. The high specific compressive strength, and high specific elastic modulus of alumina ceramic allow engineers to design Pressure Housings having weight-to-displacement ratios lower than 0.60 for a service depth of 20,000 feet while remaining neutrally buoyant. Titanium Housings designed to the same requirements have weight-to-displacement ratios in excess of 0.85. Although the difference may, at first glance, seem negligible, it accounts for a tripling of the Housing payload weight capacity when alumina ceramic is substituted for titanium. The transition of alumina-ceramic Pressure Housing components from the developmental stage to the operational environment brings on the requirement for the capability of nondestructively inspecting these components for gross fabrication flaws and for in-service damage which may have occurred. Various radiographic and ultrasonic inspection methods are evaluated and compared based on their ability to detect defects, determine defect location, and characterize defect size and shape in large alumina-ceramic components used for deep submergence Pressure Housing applications. Recommendations based on the findings of the study are made for the nondestructive inspection of alumina-ceramic components.
Tim J. Noyes - One of the best experts on this subject based on the ideXlab platform.
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DEEPi: A miniaturized, robust, and economical camera and computer system for deep-sea exploration
Deep Sea Research Part I: Oceanographic Research Papers, 2019Co-Authors: Brennan T. Phillips, Stephen Licht, Karla S. Haiat, Jake Bonney, Josh Allder, Nicholas Chaloux, Russell Shomberg, Tim J. NoyesAbstract:Abstract Cameras are essential components to almost every underwater vehicle including ROV’s, AUV’s, manned submersibles, ocean observatories, and baited remote underwater video systems (BRUVs). Deep-sea cameras are traditionally expensive components, and are almost exclusively fabricated as one-atmosphere Pressure Housings made of aluminum, stainless steel or titanium, combined with custom-made optical viewports. In autonomous recording systems such as BRUVs and biologging animal tags, camera size and form factor directly influences the physical design of the entire system and limits the operational endurance. In this paper, we describe a novel design for DEEPi, a deep-sea imaging and control system based on the Raspberry Pi family of single-board computers. The DEEPi camera is an extremely compact remote head unit (∼16 ml volume), can operate to depths of at least 5500m, and uses a photopolymer 3D-printed shell partially filled with epoxy as a Pressure Housing. A flat polished borosilicate glass disc serves as the optical viewport, and protects the lens assembly from Pressure and water intrusion. The control computer is completely potted in epoxy, and is accessible through a wifi connection. The DEEPi system is described in detail, along with example imagery from deep-sea deployments to depths of up to 1096m.