ABSTRACT Nextel™ 312/Blackglas™ composite densification via repeated cycles of infiltration TM wi... more ABSTRACT Nextel™ 312/Blackglas™ composite densification via repeated cycles of infiltration TM with the Blackglas precursor materials and pyrolysis were studied. Nicalon™/Blackglas composite specimens with graphite foil as simulated delaminations in various layer locations were evaluated. Results show unique capabilities of nondestructive X-ray microtomographic and ultrasonic evaluation in characterizing processing- and failure-related microstructures.
Capabilities and limitations of X-ray computed microtomography (CT) in characterizing relevant co... more Capabilities and limitations of X-ray computed microtomography (CT) in characterizing relevant composite material issues as identified during manufacturing processes were investigated. Damage in engine subcomponents was evaluated and compared with damage detected in pedigreed coupon type specimens. The system used is a newly developed state-of-the-art X-ray computed tomography system capable of providing digital radiography, computed tomography, and computed laminography. CT
Scaling up the Single Transducer Thickness-Independent Ultrasonic Imaging Method for Accurate Cha... more Scaling up the Single Transducer Thickness-Independent Ultrasonic Imaging Method for Accurate Characterization of Microstructural Gradients in Monolithic and Composite Tubular Structures. Don J Roth, Dorothy V Carney ...
Health Monitoring of Structural and Biological Systems 2009, 2009
Rotor health monitoring and on-line damage detection have been increasingly gaining interest to m... more Rotor health monitoring and on-line damage detection have been increasingly gaining interest to manufacturers of aircraft engines, primarily to increase safety of operation and lower the high maintenance costs. But health monitoring in the presence of scatter in the loading conditions, crack size, disk geometry, and material property is rather challenging. However, detection factors that cause fractures and hidden internal
Smart Sensor Phenomena, Technology, Networks, and Systems Integration 2013, 2013
ABSTRACT Safety and maintenance cost are among the major features that engine manufacturers striv... more ABSTRACT Safety and maintenance cost are among the major features that engine manufacturers strive for in their design approach to produce efficient and successful products. However, this design success is subject to manufacturing highly reliable rotating components that typically undergo high rotational loading conditions that subject them to various types of failure initiation mechanisms. To counter such design concerns; health monitoring of these components is becoming a necessity, yet, this attribute remains somewhat challenging to implement. This is mostly due to the fact that presence of scattered loading conditions, crack sizes, component geometry and material property hinders the simplicity of imposing such applications. Therefore, exploitation of suitable techniques to monitor the health of these rotating components is ongoing and investigating other means of inspections such as non-destructive approaches to pre-detect hidden flaws and mini cracks is also being considered. These approaches or techniques extend more to assess materials’ discontinuities and other defects that have matured to the level where a failure is likely. This paper is pertained to presenting data collected from a spin experiment of a turbine like rotor disk tested at a range of rotational speeds up to 12000 rpm. It further includes an analytical modeling of the rotor vibration response that is characterized by a combination of numerical and experimental data. The data include blade tip clearance, tip timing measurements and shaft displacements. The tests are conducted at the NASA Glenn Research Center’s Rotordynamics Laboratory, a high precision spin rig. The results are evaluated and scrutinized to explore their relevance towards the development of a crack detection system and a supplemental physics based fault prediction analytical model.
... George Baaklini NASA Glenn Research Center 2 IOOO Brookpark Road Cleveland, OH 44 I35 ... Thu... more ... George Baaklini NASA Glenn Research Center 2 IOOO Brookpark Road Cleveland, OH 44 I35 ... Thus, thermal and bending fatigue may be responsible for the reductions in coupon strength and presence of damage as determined through NDE. ...
Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; General, 1994
ABSTRACT Nextel™ 312/Blackglas™ composite densification via repeated cycles of infiltration TM wi... more ABSTRACT Nextel™ 312/Blackglas™ composite densification via repeated cycles of infiltration TM with the Blackglas precursor materials and pyrolysis were studied. Nicalon™/Blackglas composite specimens with graphite foil as simulated delaminations in various layer locations were evaluated. Results show unique capabilities of nondestructive X-ray microtomographic and ultrasonic evaluation in characterizing processing- and failure-related microstructures.
Capabilities and limitations of X-ray computed microtomography (CT) in characterizing relevant co... more Capabilities and limitations of X-ray computed microtomography (CT) in characterizing relevant composite material issues as identified during manufacturing processes were investigated. Damage in engine subcomponents was evaluated and compared with damage detected in pedigreed coupon type specimens. The system used is a newly developed state-of-the-art X-ray computed tomography system capable of providing digital radiography, computed tomography, and computed laminography. CT
Scaling up the Single Transducer Thickness-Independent Ultrasonic Imaging Method for Accurate Cha... more Scaling up the Single Transducer Thickness-Independent Ultrasonic Imaging Method for Accurate Characterization of Microstructural Gradients in Monolithic and Composite Tubular Structures. Don J Roth, Dorothy V Carney ...
Health Monitoring of Structural and Biological Systems 2009, 2009
Rotor health monitoring and on-line damage detection have been increasingly gaining interest to m... more Rotor health monitoring and on-line damage detection have been increasingly gaining interest to manufacturers of aircraft engines, primarily to increase safety of operation and lower the high maintenance costs. But health monitoring in the presence of scatter in the loading conditions, crack size, disk geometry, and material property is rather challenging. However, detection factors that cause fractures and hidden internal
Smart Sensor Phenomena, Technology, Networks, and Systems Integration 2013, 2013
ABSTRACT Safety and maintenance cost are among the major features that engine manufacturers striv... more ABSTRACT Safety and maintenance cost are among the major features that engine manufacturers strive for in their design approach to produce efficient and successful products. However, this design success is subject to manufacturing highly reliable rotating components that typically undergo high rotational loading conditions that subject them to various types of failure initiation mechanisms. To counter such design concerns; health monitoring of these components is becoming a necessity, yet, this attribute remains somewhat challenging to implement. This is mostly due to the fact that presence of scattered loading conditions, crack sizes, component geometry and material property hinders the simplicity of imposing such applications. Therefore, exploitation of suitable techniques to monitor the health of these rotating components is ongoing and investigating other means of inspections such as non-destructive approaches to pre-detect hidden flaws and mini cracks is also being considered. These approaches or techniques extend more to assess materials’ discontinuities and other defects that have matured to the level where a failure is likely. This paper is pertained to presenting data collected from a spin experiment of a turbine like rotor disk tested at a range of rotational speeds up to 12000 rpm. It further includes an analytical modeling of the rotor vibration response that is characterized by a combination of numerical and experimental data. The data include blade tip clearance, tip timing measurements and shaft displacements. The tests are conducted at the NASA Glenn Research Center’s Rotordynamics Laboratory, a high precision spin rig. The results are evaluated and scrutinized to explore their relevance towards the development of a crack detection system and a supplemental physics based fault prediction analytical model.
... George Baaklini NASA Glenn Research Center 2 IOOO Brookpark Road Cleveland, OH 44 I35 ... Thu... more ... George Baaklini NASA Glenn Research Center 2 IOOO Brookpark Road Cleveland, OH 44 I35 ... Thus, thermal and bending fatigue may be responsible for the reductions in coupon strength and presence of damage as determined through NDE. ...
Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; General, 1994
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