Crimson Racing Wiki

Chassis System

Subteam: ChassisSubsystem: PedalsAssembly: Chassis SystemCars: CR22

Purpose

The assembly line covering the frame and its integral tabs and mounts.

Function

Groups the frame with the tab sets each subteam mounts to, the tube end caps, and the mounts carried directly on the frame. Design Philosophies and Processes: Inherited from the Frame subsystem design process: 1. Kinematics supplies the pickup points and an LLTD range; the intersection of the frame-stiffness curve with that range sets the torsional stiffness target (CR26E: 1651 lb-ft/deg design target, from an LLTD target of 41.6% within a 39.5-42.5% range). 2. Model in SolidWorks 1D beam element FEA: couple moment across the front axle, rear upright points fixed, actuation geometry as trusses, representative engine tubes, displacement measured at the front upper pickup points. 0.5 in mesh spacing after a convergence study. 3. Physically test on the torsional stiffness jig: solid dampers installed, rear spindles fixed, front spindles on a pivot beam, weights hung at known distance. Historical FEA error 2.94% (CR22), 10.23% (CR25), 19.60% (CR26E). 4. Analyse each suspension tab for bearing stress and bending at its critical load case. 5. Weld in CNC-milled 6061 jigs with dowel pins; heat treat suspension nodes; FARO the finished frame.

Reoccuring issues

None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.

Still to document

Nothing in CrimsonStorage covers these yet.