1. Union College Mechanical Engineering
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 2003
Châlons en Champague
CompTest 2003

2. Agenda Grids Isogrids Advantages of Thermoplastics
Prototype Isogrid Project
Manufacturing
Experimental Evaluation
Results and Conclusions
30 January 2003
Châlons en Champague
CompTest 2003

3. Advantages of Grid Structures
Highly Efficient
Damage Tolerant
Redistribution around damage
Take Advantage of the Anisotropy of Composites
Potential in Composites for Fabrication Automation
30 January 2003
Châlons en Champague
CompTest 2003

4. Grid Types Quadri-Directional Tri-Directional Orthogrid Anglegrid
30 January 2003
Châlons en Champague
CompTest 2003

5. History of Isogrids British Vickers Wellington Bomber
McDonnell Douglas (1960)
Payload Fairings, Edwards AFB (mid 80s)
Aerospace Applications
30 January 2003
Châlons en Champague
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6. Thermoplastics Provide Significant Advantages
In Situ Processing
Effective Repair
Recycling
30 January 2003
Châlons en Champague
CompTest 2003

7. Prototype Study Manufacture Isogrid Test Analogs
Optimization of Isogrid Configuration
Manufacturing Automation
30 January 2003
Châlons en Champague
CompTest 2003

8. Isogrid Mold
30 January 2003
Châlons en Champague
CompTest 2003

9. Isogrid Lay-Up Pattern
30 January 2003
Châlons en Champague
CompTest 2003

10. Experimental Evaluation
Compare Composites to Aluminum and Steel
Develop Understanding of Impact of Lay-Up Pattern
Experimental Methods
3 Point Bend
30 January 2003
Châlons en Champague
CompTest 2003

11. Prototype Isogrid
30 January 2003
Châlons en Champague
CompTest 2003

12. Speckle Image Photogrammetry
30 January 2003
Châlons en Champague
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13. Analog Results
30 January 2003
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14. Performance Summary Flexural Rigidity D=Et3/[12(1-2)] Gl/Ny isogridST Al
solid St
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
1.71
37.5
10.2
220
Flexural Rigidity D=Et3/[12(1-2)]
30 January 2003
Châlons en Champague
CompTest 2003

15. Full Field Results
30 January 2003
Châlons en Champague
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16. Grid Comparisons
30 January 2003
Châlons en Champague
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17. Next Steps
30 January 2003
Châlons en Champague
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18. 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 2003
Châlons en Champague
CompTest 2003

19. Acknowledgements and QUESTIONS?
Students
Rebecca Terry, Matt Bamford, Paula Denemma, Jenny Moon, Matt Hilbert
Orgaizations
National Science Foundation
Automated Dynamics Corp.
NASA
30 January 2003
Châlons en Champague
CompTest 2003