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

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

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

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.

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

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

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

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

Safety Factor Maximum Repeating Force: Sn’ = Sn*Cm*Cs*Cr*Cst N = 2 Sn’ = 96.7 ksi Sn’/N = 48.35 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

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

Cost Analysis Item Amount Price 1.325 “ OD x 1.209 “ ID 4130 Alloy Steel Tube 119.2’ (15 * 8’ pieces) 20.1” (1 * 2’ piece) $1319.50 $162.25 Shipping 1/8” ER80S-D2 TIG Filler Rods 15 lbs. $142.50 $41.33 Shipping Waste & Error Factor 15% $249.84   Total Cost $1915.42 4130 Not readily available locally – must be ordered online

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

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