Astronaut’s coat hanger [Fall 2021]

Course: Engineering Design I

Task: To create an acrylic coat hanger for an astronaut’s surface suit (40 lb) in a Mars Habitat

Challenge/constraints:

  • Minimize mass

  • Satisfy geometric conditions (hanger is flush against mounting plates, and not touching forbidden/red zones or pinned in restricted/green zones.

Tools: SolidWorks (CAD and FEA), laser cutters (Rabbit Laser)

Material: 1/4 “ acrylic

 

Process

1)

Initial sketches (accounting for forbidden and restricted zones)

2)

Hand calculations:

  • Performed simple stress analysis to assess most likely failure modes (compression/buckling, axial stress, bending, etc.)

  • Used a Factor of Safety (FoS) of 2.5 to solve for minimum width dimensions

3)

Created CAD model to dimension in SolidWorks

4)

Performed complex stress analysis using FEA to find the points and values of highest stress, maximum displacement, and FoS to compare with hand calculations.

5)

Prototyped using laser cutter (Rabbit Laser, RDWorks) with part with final mass = 13.3 g

6)

Tested on rig; success!