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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. Agenda. Grids Isogrids
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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 CompTest 2003
Agenda • Grids Isogrids • Advantages of Thermoplastics • Prototype Isogrid Project • Manufacturing • Experimental Evaluation • Results and Conclusions CompTest 2003
Advantages of Grid Structures • Highly Efficient • Damage Tolerant • Redistribution around damage • Take Advantage of the Anisotropy of Composites • Potential in Composites for Fabrication Automation CompTest 2003
Grid Types • Quadri-Directional • Tri-Directional • Orthogrid • Anglegrid CompTest 2003
History of Isogrids • British Vickers Wellington Bomber • McDonnell Douglas (1960) • Payload Fairings, Edwards AFB (mid 80s) • Aerospace Applications CompTest 2003
Thermoplastics Provide Significant Advantages • In Situ Processing • Effective Repair • Recycling CompTest 2003
Prototype Study • Manufacture Isogrid • Test Analogs • Optimization of Isogrid Configuration • Manufacturing Automation CompTest 2003
Isogrid Mold CompTest 2003
Isogrid Lay-Up Pattern CompTest 2003
Experimental Evaluation • Compare Composites to Aluminum and Steel • Develop Understanding of Impact of Lay-Up Pattern • Experimental Methods • 3 Point Bend CompTest 2003
Prototype Isogrid CompTest 2003
Speckle ImagePhotogrammetry CompTest 2003
Analog Results CompTest 2003
Performance Summary Flexural Rigidity D=Et3/[12(1-2)] CompTest 2003
Full Field Results CompTest 2003
Grid Comparisons CompTest 2003
Next Steps 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 CompTest 2003
Acknowledgements and QUESTIONS? • Students • Rebecca Terry, Matt Bamford, Paula Denemma, Jenny Moon, Matt Hilbert • Orgaizations • National Science Foundation • Automated Dynamics Corp. • NASA CompTest 2003