Research, Design, Manufacturing of Formula Student Racecar

Team Members:

- Shreeraj Kurkure (4626)

Team Name:- Triumphant Racers

- Shreeraj Kurkure

1. VEHICLE DYNAMICS

Design Objectives Develop most efficient Suspension configuration. Reliable Steering geometry. Wheel Alignment – Better Traction. High Acceleration Performance. Identify relevant design parameters – Load Transfer. Real-time Simulation. Manufacturabilty & Simplicity. Driver Comfort. Maintain easy adjustability for further tuning. LAP Concept.

Design Requirements Minimum 60” wheel base

Unequal front & rear track widths Minimum 1” ground clearance Minimum 2” total suspension travel Template must pass through frame Spherical bearings must be in double shear Design must handle applied loading

Rate of camber angle change with respect to both body roll and wheel displacement

Design Goal

Design Features Double Wishbone with 4-wheel Independence. Unequal, Non-parallel Control Arms. Length Adjustablilty. - Threaded Chassis Mounts. Camber Adjustabilty. - Aluminium shims. Anti-Roll Bars. Push-rod actuated Dual-Shock Monotube Dampers at

Front. Pull-rod actuated Mono-Shock Monotube Damper at Rear. No REIB.

Design Methodology Considerations:-1. Car Total Mass = 300kg (with 68kg driver)2. Track Width (F/R) = 1260/1160 mm3. Wheelbase = 1680 mm4. Total Mass Distribution = 48% (Front) 52% (Rear)5. Natural Frequency = 2 (F)/2.2 (R) Hz6. Tire Rate = 90000N/m7. Tire Deformation at Max. Load Transfer = 6mm8. Rim Size = 13 inches9. Lateral Acceleration = 1.5g10. Total Mass CG Height = 275mm

Step-1: Determination of CG and Static Loading Unsprung Mass (Wheel Assembly+Tires+A-arms):- Front = 10.5kg per wheel Rear = 11.75kg per wheel Sprung Mass:- Suspension Assembly = 11.3kg Steering Assembly = 6kg Pedal Assembly = 8kg Engine+Gearbox+Drivetrain = 80kg Chassis+Seat+Bodyworks = 68kg Total Car Mass = 300kg (with 68kg driver)

Total Mass CG Co-ordinates:- From Front Axle = 873.6 mm From Rear Axle = 806.4 mm Height from ground = 275mm

Step-2: Front View Swing Arm Length and Roll Center Location

Roll Center height:- Front = 38.4mm above groundRear = 66mm above ground

Step-3 : Estimation of Rates

Motion Ratio(F/R) = 1.4/1.2 Ride Rate(F/R) = 19423.38N/m / 25317.5N/m Wheel Rate(F/R) = 24738.23N/m / 36331.34N/m Spring Rate(F/R) = 12637.186N/m / 24535.92N/m Roll Stiffness:- 1. Due to Tires(F/R) = 1426.57N/roll / 1056.31N/roll 2. Due to Springs(F/R) = 451 N/roll / 758 N/roll Max Body Roll Angle = 2.35degrees

Suspension Dynamics Analysis in OptimumK Software

Final Suspension Design

Manufacturing Control Arms

Push Rod Rocker

Sway Bar

Manufacturing Suspension System – Front Assembly

Geometry Testing & Perfomance Evaluation

Dynamic Camber Change Load Transfer along 3 axes Damper & ARB Effectiveness

Jounce & Rebound Body Roll Total Damping Offered

Future Testing PlansStrain gauge and accelerometer data logged during driving

Mychron 3 data logger with internal Accelerometer

Strain gauges