Meeting Agenda:

1. Review Deliverables

   1. FEA Setup Justification

   2. Mass Analysis

2. Assign Week 2 Deliverables

1.a Most collisions outside of ASC, explicit dynamic analysis makes the most sense

Matt said - the way the load was worded → “5G” instead of a speed. A lot of teams chose to do that instead of dynamics analysis. Therefore static analysis was the easiest was to pass ASC.

1.b Mass Analysis

• Didn’t get to dig into simulations

• maximum 3 vehicle collision scenarios; enough mass configurations (hopefully some are redundant)

• Timeline - busy and unable to deliver until Tuesday (19)

Action Items:

1. Read ASC Regs related to Structural FEA + Review the confluence pages for research related to setup justification + simulation setup.

2. New Goals have been set

Night of Tuesday, May 18 - Min finishes Mass Analysis Study

Tuesday/Wednesday May 18/19 - Review Mass Analysis Simulations with Tommy + Create small report for Mech Advisors (Leif, Matt, and Kevin + Catherine) to review and approve

Thursday, May 20 - Begin Stage 2 deliverables (assuming stress values are still not solved

Saturday, May 22 - Have mech-leads meeting to review progress and give training on Stage 2 deliverables

Night of Tuesday, May 25 - Finish Stage 2 deliverables

Tuesday/Wednesday May 25/26 - Review Stage 2 deliverables + Create small report for Mech Advisors (Leif, Matt, and Kevin + Catherine) to review and approve

May 31 - Complete Supplier Interfacing Logistics for approved solution

• 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

Meeting Agenda:

• Sync Up on each person’s progress and availability for the next week

• Mentioning about additional 1 or 2 weeks of timeline because of component design aspects and review

• Bring in more people to this project

  • get to help out with minor stuff, etc.

  • delegate mesh convergence - Ansys has mesh convergence tool - Ask Matt / Adam

Meeting Agenda:

• Sync Ups and Updates and Blockers

• New task - get more accurate masses of battery box and dynamics mounting 😮 since we have random 100 kg mass points everywhere. Those should be justified!!!

• Distribute work

Updates:

• Tommy - completed mass (got an approximation but could be improved)

  • mesh convergence studies on simulation was blocked (remote bay computers offline)

• Kimberly -

  • made progress

  • blocked by offline remote bay computers

• Min -

  • Mesh convergence tool doesn’t work on beam tools

  • Working on sheet metal into Chassis

  • blocked by bay computers

• Sheet metal placement (ASC Regs + Communicate with Interiors)

  • need to figure out occupant space and assembly interference

  • Component design of how the sheet metal would be installed onto the Chassis

    • Material Selection page by kimberly had some research about mounting parts

• Updated Master Assembly (Announcement into Chat)

• Updated Mass Assembly

Meeting Agenda:

1. Updates

2. Next Steps

3. Timeline Management

Updates:

• Tommy

  • Created an updated master assembly (again) lol

    • Updated Vehicle Assembly - Mechanical - Confluence (atlassian.net)

    • Some items aren’t up to date, but I still placed the dummy geometries inside to at least be able to visually see where things might interfere

  • Did more updated calculations on some mass items

    • the dynamics assembly masses in simulation no longer needs to be 100 kg.

      • Maybe lessen it to 50 kg and 70 kg respectively for example.

    • battery box is currently estimated to be ~60-65 kg + catamaran cover to be ~25 kg

    • Therefore we can reduce the point masses in simulations to more modest quantities

    • Create new task of accurate value for catamaran cover and battery box

  • Mesh Convergence Study on Tube Solution

    • as mesh size decreased, stresses increased and percent error increased

  • My confluence pages are messy

    • clean up → 1 page and not 2 jumping around

    • clean up updated project planning page

  • Tommy needs to start thinking about this project management and planning more

• Min

  • will be MIA for the next 2 weeks until after midterms

  • not much progress done on fea project this week

• Kimberly

  • Not too much work done this week

  • Looking to finalize and test out new collision object setup in ansys

  • hoping to get most of the work done this weekend and update confluence pages as progress is made

• Jens

  • spent a lot of time on design space

    • published Confluence page

    • looked through Regs - picked out potentially relevant ones + fasteners

      • fairly self-explanatory

  • finished all items except component design of sheet metal

• Aidan

  • will get started with helping Min

  • spend next week getting trained and familiarizing

  • after midterms, beginning helping with work shifts with Min on sheet metal solution task

New Tasks:

• Updated masses for catamaran cover + battery box? (Tommy)

  • it looks like it is close to 100 kg and so we can’t confidently reduce the point mass in simulations

• Updated master assembly (Tommy)

  • reach out to DRI’s for updated CAD file and positioning

• Mesh convergence studies (Tommy)

  • do finer meshes

• Work on Component design of sheet metal mounting (Jens)

• Re-organizing and project planning (Tommy)

Meeting Agenda:

• Updates

• Next Steps

• confirming availability with min and aiden

• bi-weekly goals - wednesday + saturday

Updates:

• Jens

  • Some progress made at the bottom

  • Sheet Metal Reinforcement Design Space - Mechanical - Confluence (atlassian.net)

• Tommy

  • need to complete follow-up tasks

  • will use remote desktop at weirder times so high priority projects can be worked on

• Kimberly

  • still working on collision setup

    • testing out on ansys

  • will try to take measurement of chassis sometime this week

    • CAD file afterwards

    • simulation TBD

• Aidan

  • got familiar with project

  • useful to go through video series

• Min

  • had an incorrect CAD

    • starting all over

    • just on wrong side of tubes + interference check with other assemblies

  • should create a baseline CAD model to start FEA

    • will send out baseline CAD model after to stakeholders for them to inspect their own interferences with their subassemblies

    • Can finish CAD model by Wednesday

  • Simulation side of things

    • Aidan can start taking a look at internal contacts

    • maximum 5 hours

    • can finish by Wednesday

      • will receive CAD model thursday and work on it afterwards

Meeting Agenda:

• updates + some next steps

• troubleshooting simulations possibly

Meeting Notes

• Tommy

  • no updates

• Jens

  • incorporated feedback

  • do full detailed design

• Min

  • I was able to get that reinforcement-chassis contact working. I just need to update the model and run it now, should be done in the afternoon/evening before the structures meeting

• Kimberly

  • running into issues with front bar - frictionless contact

Task –

• detailed material selection?

Meeting Agenda

• Sync-ups with Min and Kimberly

• Next steps provided by Mech Advisors

Meeting Notes

• Kimberly

  • Context: Vehicle Collision Object Setup

  • Stuck on frictionless contact.

    • There are linear(will solve) and nonlinear contacts

    • nonlinear contacts are frictionless, rough, friction

    • only way to get frictionless to solve is to fix a bunch of chassis tubes

  • Mock-up model

    • using older version of chassis model

    • see if results get better or not → pursue or not

• Min’s notes from Mech Advisor FEA review meeting

  • notes from my meeting with the advisors, turns out they do not bite at all and we NEED to use them faaaarrrrr more often! lets bug them (especially Matt, Jason, Shalin as they're chassis specialists) more often!!!!!
    Another notable thing that came out was that this "replicate the bottom panel" mantra seems to be running close to the end of the road. It no longer really seems to be addressing the problems that we are running into.
    Matt suggested a more iterative approach where we take the VDR sims, strip the BP, see the stresses and add tubes to address the stresses. Repeating this in an iterative design manner should be able to more accurately address the overall problem we are facing
    More points can be found in the doc, these are just initial and large thoughts.
    I'm going to follow up with Jason as he expressed interest in coming in this weekend to have a nice FEA grind session in person and try to see if our sims are accurate

• Kevin

  • Reach out to Matt, Shalin, and Jason to help full-detail review FEA

    • check all definitions, conditions, etc.

    • do a fine comb-through through FEA

    • messenger + individually reach out

  • Have we looked at setups from Matt, Shalin, Jason’s FEA sim

    • substitute new chassis model into old fea project files (MS12, MS14)

    • worried that chassis setup may have changed overtime

  • It was strange that the sheet metal did not improve stresses when the bottom panel did

    • create a virtual sheet metal that bonds with all the tubes that the bottom panel did

    • meeting was more focused on uncertainty regarding the results were accurate

  • If locations of high stresses are not where you are beefing up, it will remain high

    • if an area has high stress, it should be reinforced or provided a load path to lower the stress

  • Rope in more mech advisors and multiple advisors

    • varied opinions

    • specialty of advisors

    • Dynamics - Kevin, Devon, Robin

    • Chassis - Shalin, Matt, Jason

    • Composites - Adrian, Adam, Matt, Jason, SJ

  • Setup multiple 1on1’s?

    • Regardless, show off the entire chassis model and expose everything

    • Or send FEA model and ask them to look through it

    • Want to avoid saying yes to everything, and instead fully examine every aspect.