1. LUKE BLOCKER & BRANDT LAMONTE ADVISOR: HO-HOON LEE
SAE Baja Frame Team 1
LUKE BLOCKER & BRANDT LAMONTE
ADVISOR: HO-HOON LEE

2. Initial Design Factors
SAE Rules
Compliance with driver safety regulations
Drivetrain Team
Provide surface for motor mount
Room requirements for power train
Suspension Team
Provide strong enough mounting structure for Arms and Shocks
Steering Team
Provide clearance and mounting surface for Rack & Pinion steering

3. Initial Frame Design Basic Frame Geometry
Filled all foreseen needs at time of design
Not tested for strength

4. Assumptions Made for Force Calculation
Suspension
Angle of spring dampers equal to 30°
Angle of spring dampers held constant on impact
Spring dampers remain rigid on impact
Weight
Total weight of frame and mounted components equal to 225 lbs.
Total curb weight of 560 lbs.

5. Calculation of Forces Moment around front of frame
Summation of all Y forces to give reaction forces at wheels
Calculation of forces on frame from a rigid suspension

6. At-Rest Stress Analysis
Resting frame stress approximately 13 MPa
Minimal Stresses in front
Concentration of stress largely in rear
Rear hosts most of the mass, thus causing stress concentration

7. Addition of Cross Members
Early frame had many areas of stress concentration
In order to combat this, cross members were added to alleviate these stresses
Note stress concentration (red) at rear bend of roll cage

8. Effects of Cross Members
The addition of cross members in the roll cage provided stress relief in the critical area
This method was applied throughout the frame in order to maximize frame strength

9. Safety Factor Maximum Repeating Force: Sn’ = Sn*Cm*Cs*Cr*Cst N = 2
Sn’ = 96.7 ksi
Sn’/N = MPa
Sn’ = Sn*Cm*Cs*Cr*Cst N = 2
where:
Sn = Endurance Limit = 27.5 ksi
Cm = Material Factor = 1.0
Cst = Stress-Type Factor = .8
Cr = Reliability Factor = .75
Cs = Size Factor = .85

10. Material Selection 4130 Steel Alloy fits within our design window.
Provides ease of welding & good impact resistance
Yield stress of 460 MPa
Excellent Strength/Weight Ratio
Material of choice for SAE Baja

11. Cost Analysis
Item
Amount
Price
1.325 “ OD x “ ID 4130 Alloy Steel Tube
119.2’ (15 * 8’ pieces)
20.1” (1 * 2’ piece) $
$ Shipping
1/8” ER80S-D2 TIG Filler Rods
15 lbs.
$142.50
$41.33 Shipping
Waste & Error Factor
15%
$249.84
Total Cost $
4130 Not readily available locally – must be ordered online

12. Final Frame Design
Dimensions:
83” L
46.5” H
28” W

13. Frame Team 1 Luke Blocker & Brandt Lamonte
Solidworks 3D Model
Stress Analysis
Findings-Based Cross Members
Crash Test Analysis
Area for Component Mounting
Material Choice
Cost Analysis