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NEW TEAM ID : 15094OLD TEAM ID : 14182CAR NO : 79TOTAL SCORE : 583
1 SRI VENKATESWARA COLLEGE OF ENGINEERING CHENNAI-602117
2S.No Rule
Rulebook Reference
DesignCriteria Our Design
1 Vehicle Width B1.1.2 ≤ 1620 mm (64”) 1270 mm (50”)
2 Maximum Vehicle speed B2.7 ≤ 60 kmph 55 kmph
3 Secondary memberOuter diameterWall thickness
B7.3.1≥ 25.4 mm (1”)
≥ 0 .89 mm (0.035”)28.57 mm (1.125”)1.65 mm (0.065)
4 Primary memberBending stiffnessBending strength
B7.3.12 ≥ 2791.11 N/m≥ 387.38 Nm
3635.14 N/m
719 Nm
5 Clearance between driver helmet and RHOClearance between driver body & SIM
B7.2 ≥ 152 mm (6”)
≥ 76 mm (3”)
191.2 mm (7.52”)
104.7 mm (4.1”)
6 Length between supports of non straight tubes
B7.3.1 ≤ 711 mm (28”) 691.7 mm (27.23”)
7 RRH inclination with verticalWidth of RRH at 27”(686 mm) from seat bottom
B7.3.2 ≤ 20 °≥ 736 mm (29”)
5 °863 mm (34”)
8 Height of RHO from seat bottom B7.3.3 ≥ 1041.4 mm (41”) 1156.4mm (45.52”)
9 Height of SIM from seat bottom B7.3.5 203 mm (8”) to 356mm (14”)
262.41mm (10.33”)
10 Angle of FBMup with vertical B7.3.7 ≤ 45 ° 23 °
RULE BOOK COMPLIANCE
3Specifications Traxion 2014 Traxion 2015
Overall length 2176.89 mm (85.70”) 1981.20 mm (78”)
Overall width 1397 mm (55”) 1455.8 mm (58”)
Overall height 1549.53 mm (61”) 1631.46 mm (64.23”)
Wheel base 1371.6 mm (54”) 1422.4mm (56”)
Front Wheel track 1193.8 mm (47”) 1270mm (50”)
Rear Wheel track 1143 mm (45”) 1168.4 mm (46”)
CG location
922 mm (36.31”) from front axle
807.9 mm (31.81”) from front axle
762 mm (30”)from ground
558.8 mm (22”)from ground
Weight 370 Kg 250 kg (Estimated)
Max Speed 60 Kmph 55 Kmph
Ground Clearance 317.50 mm (12.5”) 355.6mm (14”)
Roll Cage Material AISI 1018 SAE 4130
SPECIFICATIONSOBJECTIVES:
Design and Build an ATV that
Is durable & reliable.
Maximizes driver comfort,
safety & ergonomics.
Conforms to SAE Baja Rule
Book.
Is cost effective.
PERFORMANCE TARGETS: Real Time accomplishment of
calculated design
Reduce Weight
Increase Power/Weight Ratio
Increase Acceleration
Reduce Stopping Distance High Stability
Roll Cage Member
Dimensions Bending StiffnessN/m
Bending StrengthNm
Weight / Unit Length
Weight Saved
AISI 1018(2014)
OD=25.4 mmt=3.048 mm
2763.1 387.38 1.65 Kg/m -
Primary MemberSAE 4130
OD=31.75mmt=1.65mm
3633.2 717.8 1.22 Kg/m 26%
Secondary MemberSAE 4130
OD=28.57mmt=1.65mm
2602.27 572 1.09 Kg/m 34%
4WHY SAE 4130 ?
DESIGN
1. Where are we today?
• Design, Material &
Components selected &
analyzed.
2. Roll-cage.
• Built a 1:1 scaled model.
3. Suspension, Steering & Brakes.
• Researched, Selected, Analyzed.
4. Power train.
• Researched, Selected.
5. Body & Electricals.
•Components selected.
6. Safety.
•Maximum priority.
7. Innovate &Improve.
•Our previous designs
WELDING SPECIFICATIONType: Tungsten Inert Gas WeldingInert Gas : Argon gasNo. of Welding Joints : 68TIG welding rod Diameter–3 mm
BODY PANELSFire wall & Belly pan:
Aluminum Sheet – 1 mm thick
Side & Top panels: PVC Sheet – 2 mm thick
5TRAXION 15
SIDE VIEW
3D VIEW
FRONT VIEW
TRAXION 14
SIDE VIEW FRONT VIEW
3D VIEW
3D VIEW
ROLL CAGE VIEWS
EARLIER DESIGN
ANALYSIS AND LESSONS LEARNT
Uniform cross sections were used which resulted in increased weight.Complicated design resulted in tedious Sheet metal work.
IMPROVEMENTS PLANNED
Use separate cross sections for Primary and Secondary member which will reduce the weight.Avoid Unnecessary Bends which will make the Sheet Metal work easy.Reduce the number of weld jointsRestrict the maximum number of tube intersections at one node.
S.No Type Force (N)
Displacement (mm)
Von Misses Stress (MPa)
F.O.S
1 Front impact 14518 (4g) 1.36 220.37 2.97 2 Rear Impact 14518 (4g) 11.08 289.96 2.21 3 Side Impact 10889 (3g) 5.17 292.20 2.20 4 Front Bump 5444 (1.5g) 2.25 291.54 2.20 5 Rear Bump 5444 (1.5g) 9.38 356.046 1.666 Roll over 14518 (4g) 6.45 260.53 2.46 7 Torsional 10889 (3g) 5.64 324.33 1.98 8 Longitudinal
torsion 3629 3.02 148.55 4.32
9 Drop test 8202 7.37 305.35 2.10
10 BucklingAnalysis
Member Length (mm) Buckling Load (KN)Longest Member 700 17.41Shortest Member 200 208.16
ROLL CAGE ANALYSIS RESULTS 6
ModalAnalysis
Mode Frequency (Hz)
Von Misses Stress (MPa)
Deflection (mm)
F.O.S
Free-free 07 61.09 405.8 14 1.58Pre-stressed 04 55.69 489.5 11.11 1.31
FINITE ELEMENT ANALYSIS USING ANSYS
7ANSYS RESULTS
8ERGONOMICS ANALYSIS USING CATIA (Manikin)ERGONOMICS
POSTURE OF 95% PERCENTILE MALE1.Head Room : 203.2 mm (8”)2.Side Clearance : 101.6 mm (4”)3.Sitting Length : 928 mm (36.5”)4.Arm Angle : 22.13°5.Forearm Angle : 82.87°6.Hand Angle : 22.7°7.Backrest Angle : 10°8.Seat Pan Angle : 5°9.Thigh Angle : 7.83°10.Knee Angle : 162.17°11.Leg Angle : 38.7°12.Foot Angle : 100.21°
• Ease of ingress and egress due to low side impact member height
• Steering wheel and support remain away from driver’s knees.
• Hands closer to the Body.• Optimum space provided around the
driver.• Adjustable Seat.• Clear vision to the driver.
KINEMATICS
Motion Ratio 0.85 0.85
Wheel Static Deflection 76.2 mm (3”) 63.5 mm (2.5”)
Spring Static Deflection 64.77 mm (2.55”) 53.9 mm (2.12”)
Wheel Travel 254 mm (10”) 254 mm (10”) Roll Centre Height 457.2 mm (18” ) 584.2 mm (23”)
Roll Stiffness 102.48 Nm/deg 150 Nm/deg
Pitch Centre Height 228.6 mm (9”) - Anti Dive 40% 0
Maximum Track Change 50.8 mm (2”) 0
Maximum Base Change 0 16 mm (0.62”)
9SUSPENSIONParameter Front
SuspensionRear
Suspension
Dimensions DOUBLE WISHBONE
TRAILING ARM
Lower Arm Length 330.2 mm (13”)530mm (20.86”)
Upper Arm Length 279.4 mm (11”) Spring Angle 70o 80o
KINETICS
Spring Rate 13.90 N/mm (80 lb/inch)
20.33 N/mm(117 lb/inch)
Wheel Rate 10.04 N/mm(57.8 lb/inch)
14.69 N/mm (84.53 lb/inch)
Ride Natural Frequency 1.8 Hz 1.98 Hz
Wheel Natural Frequency 6.21 Hz 7.91 Hz
Combined Rate 6.60 N/mm(33.56 lb/inch)
6.60 N/mm(49.07 lb/inch)
SUSPENSION : FOX 2.0 ShocksExtended length = 617.982mm (24.3”)Maximum Deflection = 215.9mm (8.5”)
WHEEL GEOMETRY
Camber 3o (Negative)
Castor 3o (Positive)
Steering Axis Inclination 7o
Toe In 2o
Castor Trail 14.4 mm (0.56”)
Negative Scrub 10 mm (0.39”)
TraXion 15
10SUSPENSION SIMULATION USING ADAMS CAR
COMPONENTS TO BE MANUFACTURED : Wishbone Arms and Trailing Arm
-76.2 -50-25.4 0
25.450.8
76.2101.6 127
152.4177.8
010203040506070 Wheel Rate ( N/mm)
Castor Moment Arm (mm)
Scrub Radius (mm)
Wheel Travel (mm)
0100200300400500600700
Rol
l Cen
tre H
eigh
t (m
m)
Wheel Travel (mm)
EARLIER DESIGN
ANALYSIS AND LESSONS LEARNT
Low Motion Ratio resulted in excess loading on the shock absorber and wishbone arm and reduced the Wheel Rate.Usage of long brackets resulted in suspension mount failure.Wheel travel was higher than the ground clearance. Hence caused Roll cage collision with the ground during maximum wheel travel .
IMPROVEMENTS PLANNED
Increase the Motion Ratio.Usage of Short brackets.Ground Clearance is kept higher than Wheel Travel.
11STEERING
Force Analysis Value
Aligning Torque -1.544 Nm
Overturning Moment 21.524 Nm
All dimensions are in metre
TURNING CIRCLE RADIUS AND WHEEL LOCK ANGLES STEERING GEAR BOX
1.Type : Rack and Pinion
(Tata Nano Steering Gearbox)
2. Mechanism : Ackermann Mechanism
3.Steering Wheel Diameter = 317.5 mm (12.5”)
4.No of Steering Wheel Rotation
(Left Lock to Right Lock) = 3
5.Rack Travel = 101.6 mm (4”)
6.Steering Ratio = 18.62
7.Movement Ratio = 29.45
8.Rack Load = 3239.6 N (330.2 Kg)
9.Driver Effort = 55 N (5.6Kg)
10.Steering Arm Length = 164 mm (6.45”)
11.Steering Arm Angle (α) = 55°
EARLIER DESIGN
ANALYSIS AND LESSONS LEARNTLonger Steering arm reduced the lock angle which increased the Turning Circle Radius.
IMPROVEMENTS PLANNEDReduce the Steering arm length to increase wheel lock angle which reduces the Turning Circle Radius.Lower Roll Centre at Front than Rear reduces the over steer tendency.
12STEERING SIMULATION USING ADAMS CAR
COMPONENTS TO BE MANUFACTURED : Front Knuckle and Wheel Hub Material: SAE 4130 C=0.28-0.33% , Density=7.872 e-6 Kg/mm^3
-76.2-63.5 -50
-38.1-25.4
-12.7 012.7
25.438.1
50.863.5
76.288.9
101.6114.3 127
139.7152.4
165.1177.8
-10
-8
-6
-4
-2
0
2
4
6
8
Camber Angle(°)
Toe Angle(°)
Wheel Travel (mm)
Wheel Travel VS Camber & Toe angle
EARLIER DESIGN
ANALYSIS AND LESSONS LEARNT Slipping of Brakes at Front due to inadequate applied
Braking Force.
IMPROVEMENTS PLANNED Lower the C.G height. Reduces the Braking Force
required at Front.
Increase the Leverage at Pedal lever to increase
applied Braking Force.
13BRAKES Type : Disc brakes on all four wheels.
Brake Layout: Diagonal Split
Deceleration : 5.886 m/s^2
Stopping Distance : 22.0495 m (at 55 Km/hr).
Dynamic Load Front : 264.815 Kg
Rear : 165.185 Kg
Braking Force Required:
• Front Axle : 1558.7 N
• Rear Axle : 619.11 N
Braking torque : 1352.18 Nm
COMPONENTS SELECTED
1. Master Cylinder = Bosch (Ø 24 mm) (Maruti Omni)
2. Disc Diameter = 200 mm
3. Caliper = Yamaha R15 (Single Piston Ø 30 mm,
Floating Type)
Pedal Force = 250 N (Minimum Load applied by 95
Percentile Male)
Leverage in Pedal Lever = 6.96
14BRAKES SIMULATION USING MATLAB
15POWER TRAINENGINE Briggs & Stratton Engine.
• Engine Displacement : 305 cc.
• Max. Power : 10 hp @ 3800 rpm.
• Max. Torque : 18.6 Nm @ 2600rpm.
VEHICLE PERFORMANCE
Top Speed 55 Kmph
Gear Ratio CVT – 3:1 to 0.43 : 1
Gear Box – 16 : 1
Overall Gear Ratio 48 : 1 to 6.9 : 1
Power/Weight 40 HP / Tonne
Tractive Effort Max – 1464 NMin – 295.49 N
Acceleration Max - 3.79 m/s^2Min – 0.34 m/s^2
Gradability Max –41.9%Min – 3.43%
Maximum Grade – 22°
Drawbar Pull Max – 1403.43 NMin – 125.28
Dynamic Load Wf (Kg) Wr (Kg)
Acceleration(3.79 m/s^2) 104.74 264.75
Hill Climbing (22.74°) 103.7
266.8
TRANSMISSION
Continuous Variable Transmission (CVTech) + Gear Box (Mahindra Alfa)
REAR
22”x8”-12”
FRONT
22”x7”-12”
Tire Stiffness
213.939kg/cm
Engine Mounting : To isolate the engine vibration from roll cage. 4 Bushes (Elastomers) will be used under the
engine. In addition to that a high tension spring will be
placed between the engine mounting bolt head and top side of the engine base. This spring will absorb the engine’s vibration.
LAYOUT OF DRIVE TRAIN
16POWER TRAIN
EARLIER DESIGN
ANALYSIS AND LESSONS LEARNT Gear box was used without clutch which
made the Gear Shifting tedious.
Tire Diameter was larger which reduced
the Tractive effort and Acceleration
IMPROVEMENTS PLANNED Use Gear box with Clutch.
Increase CVT driver pulley fly weight
mass to 270 g and use spring with low
stiffness to increase the Pick-UP.
Customize the Gear Box to limit the Top
speed.
Reduce Tire Diameter which increases
Tractive effort and Acceleration.
ELECTRICAL CIRCUIT1750 2000 2250 2800 3000 3380 3500 3750 3900 4000
0
0.5
1
1.5
2
2.5
3
3.5
Engine Speed(Rpm)
Gea
r R
atio
17502000
22502800
30003380
35003750
39004000
0
10
20
30
40
50
60
Engine Speed(Rpm)
Veh
icle
Spe
ed(k
mph
)
CVT PERFORMANCE
Vehicle Speed vs Engine Speed
Engine Speed vs Gear Ratio
SOURCE OF
INCOME
AMOUNT(Rs)
Students (15000x25)
380000
College 100000
Sponsor 100000
Total 580000
17
SOURCE OF
INCOME
AMOUNT(Rs)
Students (20000x20)
400000
College 100000
Sponsor 100000
Total 600000WEIGHT (Kg) 2014
WEIGHT (Kg) 2015
COST & WEIGHT ANALYSIS
2015
2014Suspension4% Vehicle Transporta-
tion12%
Registration14%
Power Train10%
Tires10%
Machining10%
Miscallenous1%
Frame8%
Steering4%
Brakes2%
Travel Acco-modation
25%
COST 2014
Total Cost Rs 400680
Suspension22%
Vehicle Transportation10%
Registration11%
Power Train5%
Tires7%
Machining6%
Miscallenous2%
Frame11%
Steering4%
Brakes2%
Travel Accomodation20%
COST 2015
Total Cost Rs 535000
Tires & wheels; 48
Brakes; 10
Suspension; 47
Gearbox; 20Engine; 25
Frame; 70
Steering; 12 CVT; 8
Tires & wheels; 40
Brakes; 10
Suspension; 40
Gearbox; 15Engine; 25
Frame; 50
Steering; 10CVT; 8
18 DESIGN VALIDATION PROCESS During this process the
performance of each component is
checked after assembling.
The vehicle performance is
checked using a Chassis
Dynamometer.
Necessary changes are made and
the vehicle is tested On Road.
During Road Test process the
vehicle is run over a series of
tracks with lots of obstacles,
tedious turns, different tractive
surfaces.
Finally the Endurance test is
performed.
PROJECT PLAN & TIME LINE
Systems Failure Mode
Failure Cause Operational Effects/ hazards
Safety Effects/ Hazards
Safeguards/Backup Actions
RAN
Frame Structural Excessive load leading to excess bending stress, Metal Fatigue
Frame member buckles
Injury to Driver Use of High Factor of Safety .
(S=5 O=1 D=3)
15
Suspension System
Mechanical Excessive load leading to high bending moment at suspension mounting points.
Wheel Geometry change, Roll Cage collision with ground.
Can lead to serious injury, ride quality variations.
High factor of safety used. Wheel travel is kept higher than Ground clearance.
(S=4 O=1 D=3)
12
Steering Systems
Mechanical Tie Rod breakage, Steering arm breakage, failure of ball joint
Inability to steer
Possible Collision & Accident
Proper selection and verification of desired component
(S=4 O=1 D=2)
8
Brake System Hydraulic Brake pad wear, brake fluid leakage, less heat dissipation, faulty bleeding.
Lack of braking force, biased braking.
Collision and accidents, reduced vehicle stability.
Proper brake component selection and brake bleeding.
(S=5 O=1 D=2)
10
TransmissionSystem
Mechanical Belt slipping due to change in CVT Pulley centre distance.
Loss in Power Transmission
No control over Vehicle speed .
Proper fabrication of mountings.
(S=3 O=1 D=2)
6
19DESIGN FAILURE MODE EFFECTIVE ANALYSIS
RAN = Severity(S) x Occurrence(O) x Detection(D)
20MANUFACTURING PROCESS & COLLEGE FACILITIESCOLLEGE FACILITIES CAD/CAM Laboratory Machine Shop 1.Hydraulic Pipe Bender 2.Centre Lathe 3.Capstan Lathe 4. CNC Lathe - LMW 5.Milling Machine (Universal & Vertical) 6.Planner 7.Gear Hobber 8.Grinder (Pedestal, Surface & Cylindrical) 9.Shaper and Slotter 10.Power Hacksaw Machine 11.Radial Drilling Machine 12. Tool and Cutter Grinder Strength of Material Laboratory Weld Research Cell : TIG, MIG, Arc and Gas Welding Automotive Components Testing
Laboratory 1.Wheel Alignment Equipment 2.Suspension Testing Rig 3.Chain Test Rig 4.Chassis Dynamometer
Customer Requirements
SAE Rule Book
Design Parameters
A
A
21Faculty Advisor
Mr. K. Paul Durai
DESIGN
Krishna Kumar
ShanmugaSundaram
Sathish Kumar (Driver)
Bala Sundar
SUSPENSION
Karthikeyan
Saran
Asif
STEERING
Maniraj
Mohit R Thakur
Piyush Chopra
Arunachalam
BRAKES
VishaalKrishna
Akilan
Ram Kumar
Bala chandar
TRANSMISSION
Chandrasekar
Geethan Ramu
Raj Kumar
CaptainDhamodharan
Vice-CaptainAshwath
Fabrication Procurement Presentation Driver Treasurer Old
member
WORK ALLOCATION
THANK YOU