Virtual BAJA SAEINDIA 2014

Team Name Piranha RacingTeam ID 14127

Maharashtra Institute of Technology, Pune

Wheel base 58”

Wheel Track 50”

Vehicle Height 1.58m

Height of C.G. 22”

Ground Clearance 13”

Roll Cage MaterialO.D.

Thickness

AISI 41301.125”0.095”

Total Length of Pipe 39.23m

Weld Length 3.45m

Roll Cage - Analysis

Front Impact Stress:

216.6MPa

Side Impact Pre Stress: 446.2MPa

Side Impact Post Stress:

365.1MPa

Roll Analysis Stress:

64.67MPa

Torsional Stress:

156.6MPa

Rear Impact Stress:

171.7MPa

CVT- Polaris P85 Belt CVT

Reduction Gear Drive:

Compound Planetary Differential

• Epicyclic gear train is used as differential with no speed reduction.

• Fixed – Ring gear• Input – Flange• Output 1 – Sun 1• Output 2 – Sun 2

ω(out) = ω(in) x 7

Reverse Gear Train

CVT Input

Differential

CVT ratio=R1/R2

0.78 3.84

Shaft • Self-designed • Material: 16Mn5Cr4

Dia=22 mm

Transmission

CVT OutputR2=115 mm

Engine InputR1=95 mm

• Gear Ratio = 7• Works as FNR

Kings KT 102 TractionDimension(mm): 22x8x10

Wheel

7.5511.03

13.6014.82

17.1120.22

24.7131.77

40.0060.00

0.000

0.400

0.800

1.200

1.600

ACCELERATION v/s ROAD SPEED

Engine(rpm)

Power(w)

GearRatio

Traction (N)

Air Drag(N)

Inertia(N)

Velocity(m/s)

Acceleration(m/s2)

Gradability

2000 3730.00 25.08857 1600 1.650798193 1045.436 7.55325 1.485838009 31.85770558

2400 4699.80 23.89388 1600 2.620807212 986.9174 9.517095 1.572957555 31.83547437

2800 5445.80 24.05753 1600 3.518841429 994.765 11.027745 1.55964594 31.81489748

3200 6117.20 24.47666 1600 4.439986821 1015.107 12.38733 1.527484809 31.79379581

3600 6714.00 25.08857 1600 5.348586146 1045.436 13.59585 1.482300934 31.77298626

3800 6863.20 25.90668 1600 5.588942363 1087.156 13.89798 1.425196698 31.76748219

3800 6863.20 21.04918 1300 8.466090207 859.0678 17.105206 1.451030902 25.05948271

3800 6863.20 17.81084 1100 11.82453922 733.2261 20.215244 1.422720129 20.76034664

3800 6863.20 14.57251 900 17.66381784 628.3579 24.70752 1.332578354 16.53003386

3800 6863.20 9.715004 600 39.74359014 510.3813 37.06128 1.009551889 10.08323425

3800 6863.20 8.095837 500 57.2307698 481.5426 44.473536 0.826031286 7.767741583

3800 6863.20 6.667602 411.792 104.1666667 460.4569 60 0.57035811 5.119730408

0200400600800

10001200140016001800

AIR DRAG (N)

TRACTION VS VELOCITY

INERTIA

ROLLING RE-SISTANCE

FORCES v/s VELOCITY0

5001000150020002500300035004000

ENGINE RPM v/s VELOCITY

ENGINE (RPM)

Transmission

Briggs & Stratton Model 20 Specifications:

Displacement 305 cm3

Bore x stroke 79.25 mm x 61.93 mm

Compression Ratio 8:1

Max. Power 7.5 kW @ 4000 rpm

Max. Torque 25.18 Nm @ 2200 rpm

PARAMETER FRONT REAR

Suspension TypeDouble

WishboneMcPherson

Strut

Natural Frequency 2.23 Hz 2.29 Hz

Stiffness 11.8 N/mm 32.38 N/mm

Damping Ratio 0.35 0.35

Wishbone Material AISI 4130 AISI 4130

Max. Suspension Travel 127 mm 74 mm

Transmissibility Ratio < 2.5

Spring MaterialSUP 7C

SteelSUP 7C

Steel

Toppling Speed (at min. turning radius)

20.3 kmph

Roll Gradient 5.19 deg/g

Sprung Mass 300 Kg

Un-sprung Mass 50 Kg

Pitch Frequency 1.79 Hz

Bounce Frequency 1.64 Hz

Camber Angle Variation -2.80 – 30

Suspension

CAMBERANGLE

VARIATION

SUSPENSION GRAPHS

FEA of Critical Components

Wheel Assembly

Wheel Assembly exploded

view

Steering

Ackerman Steering Geometry (Rack & Pinion System)

Wheel Base (L) 58”

Pivot to Pivot distance (t) 42”

Kingpin Inclination 7⁰

Caster Angle 3⁰

Camber Angle0 to 0.5 ⁰ ⁰

(+ve)

Toe Angle 0⁰

Scrub Radius 24 mm

Steering Arm Length 120 mm

Rack & Pinion

Steering Ratio 8:1

Rack Travel (lock to lock)

4.25”

Steering Wheel Diameter 14”

Extreme Turning Angle

Inside 35⁰

Outside 23.57⁰

Steer Angle Error (max) 2⁰

Minimum Turning Radius 2.77m

Characteristic Speed 77kmph

Parameter Value

Length of Tie Rod

12.97”

Assumed O.D. 15mm

Calculated I.D. 12.82mm

Material AISI 1026

0 10 20 30 40 50 60 7005

10152025303540

Yaw Gain v/s Velocity

Velocity (kmph)

Yaw Gain

0 10 20 30 40 50 60 7005

101520253035

Steer angle v/s Veloc-ity

Velocity (Kmph)

Steer Angle

10 20 30 40 50 600

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

Lateral Acceleration Gain v/s Velocity

Disc and Caliper assembly

Brakes

• Hydraulically actuated disc brakes on all wheels.• Two different pedal designs (offering left/right foot flexibility).• 200mm petal discs (SS304) with floating caliper.

Pedal and Master

Cylinder assembly

Part Specifications

Master Cylinder M800 (Bosch) Bore 19.05 mm

Hose STD 3/16”

CaliperApache 150 &

Suzuki GS 2 POT

Bore 26 mm

DiscTVS Apache RTR

180 Rear Disk200 mm OD120 mm ID

Performance Parameters Value

Perception Distance 16.66 m

Total Braking Force 1024 N

Deceleration 8.812 m/s2

Stopping Distance (60kmph) 13.4 m

Max. Dynamic wt. Front Axle 2200 N

Min. Dynamic wt. Rear Axle 1233.61 N

% Weight transfer 34 %

Bias Ratio (Front : Rear) 16 : 9

Design Parameters

Value

Pedal Force 100 N

Leverage (Pedal Ratio)

6:1

Piston Ratio 3.75

Braking Torque (per wheel)

71.9 Nm

Proportioning valves

TMC

Innovation

EventDesired

Sensitivity

Pedal rotation for Max Accn

(X)

Ra

(KΩ)Ra=R1+Rp

Rb

(KΩ)C

(μF)R1 Rp 00 X0

Acceleration High 120 4.0 4.0 4.0 8.0 76 – 72 0.361

Endurance Medium 180 6.0 6.0 6.0 12.0 114 – 108 0.241

Maneuverability Low 240 8.0 8.0 8.0 16.0 152 – 144 0.180

Rack & Pinion

Accelerator Pedal

Electronic Throttle Control SystemMax. Pedal Travel=300

300

IC 7806

Ergonomics & Electrical

Hand Reach EnvelopeVision Cone

Reach Limit &

Visibility

Infrared Emitter Infrared Sensor

Safety

ABC Grade 0.5 kg Fire extinguisher

INFRARED EMITTER

Component Potential Failure Mode

Potential Causes/

Mechanism of Failure

Potential Effects of Failure

O S D RPN Recommended Action

• Gearbox Provides variable torque and speed to lower power train.

• Enables effective conversion of engine power according to variable loads

Surface Wear

Abrasive Wear

Foreign particles in lubricant

Lapped finish; radial scratch marks; grooves on contacting surfaces

1 6 7 42

Oil filters; high viscosity oils; gear enclosure; regular replacement of oil; increase in surface hardness

Corrosive Wear

Chemical action of active ingredients in lubricant

Fine uniform wear 1 6 7 42Proper selection of lubricant; regular check-up and replacement of oil

Initial Pitting

Tooth profile errors; surface irregularity; misalignment

Redistribution of loads due to progressive removal of high contact spots

1 7 4 28Precise machining and alignment;

Destructive Pitting

Loads > surface endurance strength of material

Complete destruction of tooth surface and premature breaking

3 8 3 72Design gears for wear strength > (static + dynamic) loads; increase surface hardness

ScoringOverheating due to excessive frictional heat

Alternate welding and shearing

2 6 4 48Adjusting surface parameters to reduce working temp.; proper air and lubricant circulation

Breakage

Fatigue Failure

Root stress > endurance limit of material

Fretting and breach marks; breakage of part or whole tooth

2 8 2 32Design for reduced stresses; polishing and shot-peening of root fillet

Overload Breakage

Sudden overloads > tensile strength of material

Stringy fibrous break (pulled or torn apart abruptly)

2 8 2 32Design with greater factor of safety, and higher value of service factor.

DFMEA

Project Plan & Team Distribution

Team

Dis

trib

ution

(25)

Steering 1BE, 2TE

Suspension 2TE

Transmission 2BE, 2TE

CAD/CAE 1BE

Brakes 1BE, 1TE

Electrical 2SE

Innovation 3SE

Cat-Con 1BE, 1SE

Marketing/Project Planning 2SE

Aesthetics/Ergonomics

2SE

Safety 2SE

Workshop Facilities & Technical Components

Facilities Technical Components Quantity Unit Cost (INR) Total Cost (INR)

Engine 1 20000 20000

Gear Box 1 20000 20000

CVT 1 80000 80000

Steering Rack 1 7000 7000

Hub 4 5000 20000

Knuckle 4 6000 24000

Brake Calliper 4 2500 10000

Brake Disc 4 500 2000

Shafts 2 2700 5400

Shock Absorbers 4 4500 18000

Battery 1 3000 3000

Kill Switches 2 2000 4000

Steering Column 1 1800 1800

Servo Motor 1 2800 2800

Grand Total = 218000

• Weight of Vehicle with Driver: 350 Kgs• Finance Budget: INR 3.5 Lakh

Design Validation

Camber Angle Variation v/s Wheel Travel Roll Centre Height v/s Wheel Travel

Half Car Model

Thanks

Vehicle completion Date:18 January 2014

Vehicle Inspection Date: 22 January 2014

Our Sponsor

M.I.T. Pune

CAE SUPPORT