The Evaluation of the Damping Characteristics of a Hard Coating on Titanium
Engine failures due to fatigue have cost the Air Force an estimated $400 million dollars per year over the past two decades. Damping treatments capable of reducing the internal stresses of fan and turbine blades to levels where fatigue is less likely to occur have the potential for reduci...
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| Format: | Article |
| Language: | English |
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Wiley
2007-01-01
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| Series: | Shock and Vibration |
| Online Access: | http://dx.doi.org/10.1155/2007/260183 |
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| _version_ | 1849404382625398784 |
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| author | Christopher Blackwell Anthony Palazotto Tommy J. George Charles J. Cross |
| author_facet | Christopher Blackwell Anthony Palazotto Tommy J. George Charles J. Cross |
| author_sort | Christopher Blackwell |
| collection | DOAJ |
| description | Engine failures due to fatigue have cost the Air Force an estimated $400 million dollars per year over the past two decades. Damping treatments capable of reducing the internal stresses of fan and turbine blades to levels where fatigue is less likely to occur have the potential for reducing cost while enhancing reliability. This research evaluates the damping characteristics of magnesium aluminate spinel, MgO+Al2O3, (mag spinel) on titanium plates from an experimental point of view. The material and aspect ratio were chosen to approximate the low aspect ratio blades found in military gas turbine fans. In the past, work has generally been performed on cantilever supported beams, and thus the two-dimensional features of damping were lost. In this study plates were tested with a cantilevered boundary condition, using electrodynamic shaker excitation. The effective test area of each specimen was 4.5 in × 4.5 in. The nominal plate thickness was 0.125 in. Mag spinel was applied to both sides of the plate, at a thickness of 0.01 in, and damping tests were run at room temperature. The effect of the coating was evaluated at the 2nd bending mode (mode 3) and the chord wise bending mode (mode 4). A scanning laser vibrometer revealed the frequency and shape of each mode for the plates. Sine sweeps were used to characterize the damping of the coated and uncoated specimens for the modes tested. The coating increased damping nonlinearly for both modes tested in which the general outcome was similar to that found in beams. |
| format | Article |
| id | doaj-art-95306830cff34456b0f3c64a066d545f |
| institution | Kabale University |
| issn | 1070-9622 1875-9203 |
| language | English |
| publishDate | 2007-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Shock and Vibration |
| spelling | doaj-art-95306830cff34456b0f3c64a066d545f2025-08-20T03:37:01ZengWileyShock and Vibration1070-96221875-92032007-01-01141375110.1155/2007/260183The Evaluation of the Damping Characteristics of a Hard Coating on TitaniumChristopher Blackwell0Anthony Palazotto1Tommy J. George2Charles J. Cross3Department of Aeronautics and Astronautics: Air Force Institute of Technology, 2950 Hobson Way, Building 640, WPAFB, OH 45433-7765, USADepartment of Aeronautics and Astronautics: Air Force Institute of Technology, 2950 Hobson Way, Building 640, WPAFB, OH 45433-7765, USAAir Force Research Laboratory: Propulsion Directorate, 1950 Fifth Street, WPAFB, OH 45433, USAAir Force Research Laboratory: Propulsion Directorate, 1950 Fifth Street, WPAFB, OH 45433, USAEngine failures due to fatigue have cost the Air Force an estimated $400 million dollars per year over the past two decades. Damping treatments capable of reducing the internal stresses of fan and turbine blades to levels where fatigue is less likely to occur have the potential for reducing cost while enhancing reliability. This research evaluates the damping characteristics of magnesium aluminate spinel, MgO+Al2O3, (mag spinel) on titanium plates from an experimental point of view. The material and aspect ratio were chosen to approximate the low aspect ratio blades found in military gas turbine fans. In the past, work has generally been performed on cantilever supported beams, and thus the two-dimensional features of damping were lost. In this study plates were tested with a cantilevered boundary condition, using electrodynamic shaker excitation. The effective test area of each specimen was 4.5 in × 4.5 in. The nominal plate thickness was 0.125 in. Mag spinel was applied to both sides of the plate, at a thickness of 0.01 in, and damping tests were run at room temperature. The effect of the coating was evaluated at the 2nd bending mode (mode 3) and the chord wise bending mode (mode 4). A scanning laser vibrometer revealed the frequency and shape of each mode for the plates. Sine sweeps were used to characterize the damping of the coated and uncoated specimens for the modes tested. The coating increased damping nonlinearly for both modes tested in which the general outcome was similar to that found in beams.http://dx.doi.org/10.1155/2007/260183 |
| spellingShingle | Christopher Blackwell Anthony Palazotto Tommy J. George Charles J. Cross The Evaluation of the Damping Characteristics of a Hard Coating on Titanium Shock and Vibration |
| title | The Evaluation of the Damping Characteristics of a Hard Coating on Titanium |
| title_full | The Evaluation of the Damping Characteristics of a Hard Coating on Titanium |
| title_fullStr | The Evaluation of the Damping Characteristics of a Hard Coating on Titanium |
| title_full_unstemmed | The Evaluation of the Damping Characteristics of a Hard Coating on Titanium |
| title_short | The Evaluation of the Damping Characteristics of a Hard Coating on Titanium |
| title_sort | evaluation of the damping characteristics of a hard coating on titanium |
| url | http://dx.doi.org/10.1155/2007/260183 |
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