Structures - Snatch Force Masurements

[DMC1542]

Goal: Measure the snatch force of the main parachute for the vehicle.

Description: There have been concerns raised about having a loadcell being the only mechanism by which the main parachute attaches to the rocket. With no redundancy in the current design, if the load cell fails or we experience higher loads than that which it is rated for, we risk failing to recover.

As a result, we are attempting to mitigate this risk. Brainstorming has generated the following options:

1. Ditch the load cell, use a bulkhead only. The advantage is that this is significantly more secure and we have demonstrated this will stay attached even under extreme forces; but the con is that we lose the ability to measure snatch force.
2. Use a bulkhead only, but utilize strain gauges. The advantage is that we maintain the safety aforementioned, but also have the ability to measure the deformation of the material via strain gauges from which we can derive the snatch force.
3. Use a load cell, but have a redundant force path to a traditional bulkhead that acts as a fail-safe. The con here is that there is a sizeable weight increase due to added recovery hardware, which goes against our goal of increasing TWR ratio.

Action Items:

1. Understand what loads cells and strain gauges are, and how they are utilized. Research other ways to measure snatch force
2. Reach out to Professor Rho (Materials Testing professor) who can help point us in the right direction.
3. More research based on Professor Rho's feedback
4. Draft design options, test them, and add the information to the CDR template.

[JakeHalpern]

Reassigning to Will Beckson, as he is the point of contact with Professor Rho.

[DMC1542]

Notes: Very difficult to understand the behavior of the bulkhead - so the data we would yield would be very limited in scope.

Action Item:

• Continue looking into Wheatstone bridge
• There's a strain gauge that goes inside bolts, which could be promising

New Due Date: November 25th