30 january 2003 châlons en champague comptest 2003 investigation of the state of strain at the...
TRANSCRIPT
30 January 2003Châlons en Champague
CompTest 2003
Investigation of the State of Strain at the Nodal Intersections of
Thermoplastic Isogrids using Speckle Image Photogrammetry
R.B. Bucinell
Union College Mechanical Engineering
Schenectady, NY, USA
Session 10: Applications of Optical Techniques
30 January 2003Châlons en Champague
CompTest 2003
Agenda
• Grids Isogrids
• Advantages of Thermoplastics
• Prototype Isogrid Project–Manufacturing– Experimental Evaluation
• Results and Conclusions
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Advantages of Grid Structures
• Highly Efficient• Damage Tolerant– Redistribution around damage
• Take Advantage of the Anisotropy of Composites
• Potential in Composites for Fabrication Automation
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Grid Types
• Quadri-Directional
• Tri-Directional
• Orthogrid
• Anglegrid
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History of Isogrids
• British Vickers Wellington Bomber
• McDonnell Douglas (1960)
• Payload Fairings, Edwards AFB (mid 80s)
• Aerospace Applications
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Thermoplastics Provide Significant Advantages
• In Situ Processing
• Effective Repair
• Recycling
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Prototype Study
• Manufacture Isogrid
• Test Analogs
• Optimization of Isogrid Configuration
• Manufacturing Automation
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Isogrid Mold
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Isogrid Lay-Up Pattern
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Experimental Evaluation
• Compare Composites to Aluminum and Steel
• Develop Understanding of Impact of Lay-Up Pattern
• Experimental Methods– 3 Point Bend
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Prototype Isogrid
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Speckle ImagePhotogrammetry
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Analog Results
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Performance Summary
Gl/Nyisogrid
ALisogrid
STisogrid
Alsolid
Stsolid
Mass (g) 2000 2391 6712 4336 12078
Slope (MN/m) 5.013 5.538 13.43 7.589 24.59
Mass Ratio 1 1.196 3.356 2.168 6.039
Stiffness Multiplication
1 1.71 37.5 10.2 220
Flexural Rigidity D=Et3/[12(1-2)]
30 January 2003Châlons en Champague
CompTest 2003
Full Field Results
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Grid Comparisons
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Next Steps
30 January 2003Châlons en Champague
CompTest 2003
Summary
• Thermoplastic Isogrids have Unique capabilities
• Composite Isogrid Outperforms Al and Steel Isogrid
• Speckle Image Photogrammetry verifies effectiveness of node strategy
• Future Work Includes Analysis and Manufacturing Automation
30 January 2003Châlons en Champague
CompTest 2003
Acknowledgements and QUESTIONS?
• Students– Rebecca Terry, Matt Bamford, Paula
Denemma, Jenny Moon, Matt Hilbert
• Orgaizations– National Science Foundation– Automated Dynamics Corp.– NASA