Design Research

Owned by Angela Chao
Last updated: Oct 17, 2016 by Devon Copeland

Design Considerations: 

Torsional Stiffness:

  • Want to achieve maximum torsional stiffness
  • Decrease length of the beam, or increase the polar moment of inertia (increasing the diameter) of the material 
  • Get a balance between the weight and stiffness of the chassis 

Round Vs. Square: 

  • Round tubing handles torsional stresses better than square tubing
  • Square is easier to work with, align mounts, and jig up for welding 
  • Butt joints can be done on square tubing, and notching round tubing can be difficult 
  • Since the tubes for chassis will be professionally cut, notching does not present an issue 
  • Round tubing is therefore chosen 

Triangulation:

  • Triangulation of members is used to increase the torsional stiffness of the frame 
  • Each joint of the chassis should have at least three rods to complement the load path 
  • Thin walled tubing performs well in tension and compression, but poor in bending 
  • Triangulation helps mitigate this 

Mounts:

  • Suspension control arms 
  • Shocks
  • Battery box 
  • Rack and Rack Extension 
  • Lights
  • Ballast Box 
  • Steering Column 
  • Motor controllers
  • Gas and brake pedal 
  • Parking brake handle 
  • Internal panels for driver controls 
  • Towing hard point 
  • Seats 
  • Door hinges 
  • Smaller items: electrical conduits, etc. 

Mounting Considerations: 

  • Suspension should be attached to stiff portions of the chassis to help load distribution 
  • Control arm distance should be taken into consideration, and designed concurrently with the frame 
  • Have the mass towards the centre of the car to decrease the yaw inertia 
  • Driver comfort concerns with seats (seating angle, elbow space, head height, etc.) 
  • Roll hoops, front bulkhead, suspension, and battery box mounts are fixed points to be modelled around


Resources: 

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