Chassis inaccuracy investigation should use the direct method of creating accurate chassis model and running it in simulations

• it is not possible to do this without being onsite and measuring out the chassis

Conclusion: Composite solution FEA will continue, but incorporates a large SF as much as possible

• Chassis inaccuracy investigation will be an additional investigation after June 2 (when lockdown lifts) to validate the solution chosen.

  • Also provides geometrical constraints/requirements that is useful

We should also do destructive and validation testing of composites and composite joints on the solution found

• → this should be added onto the project timeline near the end, etc.

What are the real downsides of sheet metal compared to composite panels besides weight?
(Efforts of down selecting material choice for panel solution)

• Sheet metal is

  • easier to manufacture

    • we won’t have to manufacture it besides partially sizing it down

  • no testing required

  • more reliable

  • less work for us overall

Need to know more about weight:

• We can add more weight but do we care (i.e. will it surpass the weight limit?)

• S2021 Updated Masses of Sub-Team Assemblies - Mechanical - Confluence (atlassian.net)

• E.g. we can’t use steel sheet metal because it will break UCA = convincing reason

Aluminum may not be in our design space and there is an easy way to validate that:

• is it weldable, etc.

• Could have been a prescreening method before material selection and adding simulations

Order of priorities/working on things:

• Possibly steel, composites, maybe exclude aluminum

Note: Wouldn’t turn over every rock in the investigation

• also want to close out options as soon as possible before they rear their ugly heads down the line

Action Items

• Invalidate aluminum through welding or attachment research

• See if we can exclude composites

• Get updated masses of vehicles

• Mesh convergence studies

  • question mark of how accurate results are and if any results have converged

• Fixed faces of collision object to allow bowing of the collision object itself

• Contact between collision object and chassis to become frictionless

  • Would need additional ways to constrain Chassis' movement (to compile solution)

  • But there is a chance that it can improve

  • also gives gap between chassis tubes and collision object when (e.g.) the front chassis face bows in front of the collision object

  • if it was bonded - the front tubes of the chassis cannot deform in any way (infinite stiffness problems)

• Other ASC/legacy setup questioning contact mech advisors about

Material Selection Note:

• Choose a baseline material at the beginning and try to refine that material later on

• If there is a reason to change it, just need to check previous documentation