Senior Design Team 3

1. Senior Design Team 3 Ron Capalbo, Brittany Russo, Matthew Holt, Elizabeth Keighley Sponsored By: NASA ESMD Senior Design Program & Concept Selection & Design Details Final Machine Design • WANTS/NEEDS/CONSTRAINTS: • Cost is a constraint; the prototype tester must cost less than or equal to $5,000. • Size – Must fit on a bench top • Repeatability- Repeatable, consistent results under the same parameters were required. • Simplistic Operation- The tester must be operator independent • Manufacturability- The tester should be able to be reproduced in a timely manner. A modifiable tumbler was the concept chosen for this project because of its simplistic design and great modifiability. All components for assembly were able to be commercially ordered. The unique feature that separates the original tester from our design is the incorporation of interchangeable drums with varying internal geometries to achieve specific mechanisms. • Team 3’s Scope: To design and fabricate a fixture that can apply impact & mechanism randomness in a sand & aggregate-challenged environment to representative materials that provides repeatable, qualitative,& quantitative results. PROBLEM DEFINTION VIRTUAL To REAL-LIFE Final Drum Designs Different drums were designed to target each of the defined mechanisms as well as randomness. Two of these drums were built within the scope of Senior Design. PERFORMANCE GOALS • The Randomizer Drum • Geometry: Drum with 3 Different Sized Internal Baffles • Allows the Material to Experience Differing Levels of All Mechanisms BENCHMARKING VALIDATION TESTING Original Space Suit Dust Tester @ JSC in Houston, TX • The Impact Drum • Two Main Categories of Testing Were Performed: • 1. HAND TESTS: A bucket filled with sand was placed on a force sensor plate. Various test fabrics attached to known weights were dropped into the sand. By doing this, we understood what kinds of force values were needed for different levels of damage. • 2. TUMBLER TESTING • Mass of the material, speed of the drum, and size of sand particles was altered during testing. By showing that the same damage occurred after like trials, the repeatability of our device was validated. • Geometry: 2 Parallel Planes Adhered to Walls of Drum • Carries the sample to the top of the drum, and then drops it creating impact Damage Scale: 1=Low, 5=Moderate, 10=High • Other Testers Researched Included: • Mechanical Boot Tester • RoTap Sieve Shaker (UD Geological Dept.) • Bearing Testers • Abrasion Testers Future Drum Design Ideas: These preliminary designs will be handed to ILC for future development & fabrication. Nearly the entire lunar surface is covered in regolith. Regolith is highly detrimental to the spacesuit & therefore very problematic for an astronaut. • The Abrasion Drum • Geometry: circumscribed square within drum • Allows sample to slide down each wall, maximizing friction force • The Penetration Drum • Ridged inner ring all the way around drum • Creates vibratory cutting