Frame

 

 

Features

Rigid tubular space frame design
Lightweight carbon fiber shear panels
Engine block integrated as structural member
CAD validated ergonomic design
Minimum clearance specifications met

 

Rule Analysis

Rule #
Rule
Analysis
3.3.1 The Primary Structure of the car must be constructed of either: Round, mild or alloy, steel tubing (minimum 0.1% carbon) of the minimum dimensions specified in the table at bottom of rule analysis. This table was strictly followed during all aspects of design of our frame.
3.9

The Frame must include both a Main Hoop and a Front Hoop as shown in Figure 1. When seated normally and restrained by the Driver’s Restraint System, the helmet of a 95th percentile male (anthropometrical data) and all of the team’s drivers must:
a. Be a minimum of 50.8 mm (2 inches) from the straight line drawn from the top of the main hoop to the top of the front hoop. (Figure 1a)
b. Be a minimum of 50.8 mm (2 inches) from the straight line drawn from the top of the main hoop to the lower end of the main hoop bracing if the bracing extends rearwards. (Figure 1b)

These will be measured with a 95th percentile male template (Figure 2).

"Percy" has been included in all design calculations. Our car has dimensions:

a. 2.5 inches

b. 2 inches

3.10 The Main Hoop must be constructed of a single piece of uncut, continuous, closed section steel tubing per Rule 3.3.1. The Main Hoop must extend from the lowest Frame Member on one side of the Frame, up, over and down the lowest Frame Member on the other side of the Frame. In the side view of the vehicle, the portion of the Main Roll Hoop that lies above its attachment point to the Major Structure of the Frame must be within 10 degrees (10°) of the vertical. In the front view of the vehicle, the vertical members of the Main Hoop must be at least 380 mm (15 inch) apart (inside dimension) at the location where the Main Hoop is attached to the Major Structure of the Frame. Our main hoop is a single piece of steel tubing satisfying rule 3.3.1. It follows the path from the bottom of one side of the frame to the bottom of the other. The angle of our main roll hoop to the vertical is 9°.
3.11 The Front Hoop must be constructed of closed section metal tubing per Rule 3.3.1. The Front Hoop must extend from the lowest Frame Member on one side of the Frame, up, over and down to the lowest Frame Member on the other side of the Frame. The top-most surface of the Front Hoop must be no lower than the top of the steering wheel in any angular position. The Front Hoop must be no more than 250 mms (9.8 inches) forward of the steering wheel.
This distance shall be measured horizontally, on the vehicle centerline, from the rear surface of the Front Hoop to the forward most surface of the steering wheel rim with the steering in the straight-ahead position. In side view, no part of the Front Hoop can be inclined at more than twenty degrees (20°) from the vertical.
Our front hoop is a single piece of steel tubing satisfying rule 3.3.1. It follows the path from the bottom of one side of the frame to the bottom of the other. Its top-most surface is designed to be at least 1/4 inches above the steering wheel and 2.5 inches in front of the steering wheel. The angle of our front hoop from the vertical is 0°.

 

Frame Specifications  
Frame Construction Tubular space frame with bolted aluminum headrest
Material 4130 steel round tubing .5" to 1.00" dia / 2024-t3 .031" thk Al sheet 
Joining method and material TIG welding ER70-S6 filler
Targets (Torsional Stiffness or other) 2000 ft*lbs/deg
Torsional stiffness and validation method 2150 ft*lb/deg CAE FEA model
Bare frame weight with brackets and paint 32 kg