BHARATIYA VIDYA BHAVANS SPCE RACING Reg ID 30469

BHARATIYA VIDYA BHAVAN’S SPCE RACING Reg. ID: 30469 Team Members • • • • • • Sameer Kolte (C) Parshva Shah Amol Alsundkar Chaitanya Joshi Prashant Ramteke Tushar Karande Shweta Patil Gaurav Munot Pratik Baldota Jaykishan Choksi Akshay Jain Priyank Gajiwala Aniket Ghatvisave Dhruv Phadke Omkar Deshpande Mukund Lahoti Sanskar Panse Nikhil Kotasthane Sagar Dalvi Siddhant Shah Sumant Kherudkar Presented By Sameer Kolte, Aniket Ghatvisave, Pratik Baldota, Parshva Shah, Priyank Gajiwala

Project Plan

Roll cage Design: Material and Cross Section Selection • Material Used: AISI 1018 Structural Steel Property Value Ultimate Tensile Strength 460 MPa Yield Strength 365 MPa Density 7850 kg/m 3 Young’s Modulus 2 x e 11 N/m 2 Poisson’s Ratio 0. 26 - 0. 3 Cross Section Moment of Inertia (mm 4) Distance of extreme fibre (mm) Section Modulus (mm 3) Area (mm 2) Circular OD 1” 3 mm Thick 12771 12. 5 1022 207 Circular OD 1. 25” 2 mm thick 20774 15. 875 1308. 5 187 • Bracing: Circular cross section, OD =1”, pipe thickness= 2 mm

Roll cage Design: Design Methodology • Objective: To provide minimal 3 -D space surrounding the driver and ensure safety. • Driver’s measurements: • RRH design:

Roll cage Design: Design Methodology • RHO, SIM, FBM design :

Roll cage Design: Finite Element Analysis Torsional Rigidity Torsional rigidity: 2500 Nm/deg Stress Induced: 288 MPa Flexural Rigidity Stress Induced: 107 MPa

Front Impact Roll cage Design: Finite Element Analysis Front Impact: Force=7 G=24034 N Stress Induced= 319 MPa Rear Impact Side Impact Rear Impact Force=5 G=17167 N Stress Induced= 123 MPa Side Impact Force=3 G=10300 N Stress Induced= 334 MPa

Roll cage Design: Human Ergonomics • Side Impact Member Height: 9”; Kept close to minimum for less driver exit time. • Steering Wheel Position: Fixed according to driver comfort. • Driver Head Clearance: 7. 5”; Kept greater than 6” as specified in rulebook. • RRH Inclination: 8 deg, fixed according to driver back leaning. • Width of chassis: Fixed such that there is clearance of 3” between any chassis member and driver body part.

Suspension, Steering and Brakes: Chosen Configuration Brakes: • Type: Hydraulic disc brakes • Honda Aviator disc • Pulsar 220 calipers • Maruti 800 Master cylinder Suspension: • Type: Double Wishbone unequal arm suspension (Front ) Double Wishbone, Twin outer ball joint suspension (Rear) • Coil Spring and Hydraulic damping Steering: • Type: Ackerman Steering • Maruti 800 rack and pinion assembly

Brake System • Human Foot force = 40 kgf+ 20 kgf(emergency) • Pedal Ratio = 4 • Use of proportionate valve to achieve front: rear brake biasing. • Calculated stopping distance: 3. 6 metres

Suspension Design: Kinematics • Bump/Rebound travel: Front 200/-100, rear 200/-80 (mm) ; Roll angle: 5 degrees Front 0. 6 deg/deg Rear • Camber variation: Front: Static 0. 85 Data deg/inch bump, roll Rear: Camber 1. 34 deg/inch bump, 0. 42 deg/deg 0 roll angle 0 deg Caster angle 7 deg 0 deg Toe angle 0 deg Kingpin angle 8 deg 6 deg Scrub Radius 90 mm 120 mm Caster Trail 23 mm 0 mm Roll centre height 400 mm 396 mm • Toe Variation: ZERO bump steer and Roll steer

Suspension design: Spring selection Objective: • To achieve desired ground clearance of 12” • To achieve ‘oversteer’ while cornering. Spring selection: • Rear springs: Maruti Zen Front struts Measured spring stiffness ‘k’ = 21 N/mm Precompressive force= 140 kgf • Front Springs: Inhouse designed springs Target spring stiffness ‘k’ = 21 N/mm

Wheel assembly components Hubs: • Front hub: Designed hubs Torsion and Bending Braking Torque= 235 Nm Bending force= 1800 N Max Induced stress= 71 MPa Factor of safety= 6. 5 • Rear hub: Maruti 800 front hubs

Steering sub system • Ackerman geometry • C-factor = 37 mm/rev • Rack travel = 45 mm • Wheel angles: Inner= 43 deg, Outer= 35 deg • Minimum Turning radius= 4 metres

Powertrain: Engine Specifications: • Briggs and stratton 10 bhp OHV engine • Torque: approx 18. 75 Nm at 2600 rpm • Power: 10 bhp at 3600 rpm Engine mounts: • Operating frequency range: 25 Hz to 70 Hz Engine Mounts Natural frequency= 460 Hz Maximum stress induced= 23 Mpa

Powertrain: Transmission Schematic: • Engine-> CVT-> Reduction gearbox • Continuously Variable Transmission 1. CVTech CVT Ratio= 3. 6: 1 to 0. 59: 1 2. Comet 780 series= 3. 75: 1 to 0. 6: 1 • Reduction gearbox Constant reduction = 10: 1 • Final ratio= 36: 1 to 5. 9: 1

Powertrain: Reduction Differential Input from CVT Output to driveshafts Total reduction: 11. 45

Design Failure Modes And Effects Analysis (DFMEA) Items Potential Failure Mode Potential Cause of Failure Potential Effect Of Failure Remedies to avert Failure Chassis Structural Front/Rear/Side Collision Driver Injury, Chassis deformation, Damage to engine/suspension. Incorporate bracing members, Nodal Structure, Use of Bumpers. Fatigue Resonance of engine frequency with chassis natural frequency. Failure of welded joints Use of rubber pad below engine, Incorporate bracing to increase natural frequency Suspension (A-Arms, Springs, Shock absorbers) Structural Bending, compression, Force due to anti dive; Torsional shear failure of spring, Buckling Permanent buckling of spring affects ground clearance; Wishbone failure Rear twin Ball joint suspension , High Factor of safety Transmission Mechanical Cyclic loading, Radial loads due to CVT, Torsional shear stress in shafts Gear failure, Shaft failure, Misalignment of shafts in gearbox Use of standard shafts and gears, Bearings capable of taking high radial loads Brakes Structural Brake fluid contamination, Bending of brake pedal, Bending of master cylinder rod Brake system failure Master cylinder cap, Brake Bleeding, High FOS for pedal, proper Master cylinder mounting

Safety • 5 point harness. • Battery placement: Away from rotating parts, Covered to prevent fuel spill on battery. • Front and rear bumpers to protect tie rod and toe link. • Master cylinder mount at height from base of chassis to prevent brake failure. • Resilient foam material on all pipes of cockpit. • Use of fire extinguisher. Summary Data Value Overall Length 90 inches Overall height 58 inches Track Width Front: 52 inches Rear : 50 inches Wheelbase 66 inches Gear Ratio 36: 1 to 5. 9: 1 Estimated Weight of vehicle Gross Weight : 350 kg Kerb Weight : 290 kg Estimated Weight of chassis 55 kg with all mounts and welds

3 -D view of car