TEAM ZENITHBAJA Virtuals-2015

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Old Team ID : 14083Car number : 36Total Score: 234.56Rank : 84

TEAM ID : 15071G.B. Pant Engineering College

B7.2 Lateral Space: The driver’s helmet shall have 152 mm (6 in.) clearance, while the driver’s shoulders, torso, hips, thighs, knees, arms, elbows, and hands shall have 76 mm (3 in.) clearance.

B9.1.2 Safety Harness Expiration: All driver restraint systems must meet either SFI Specification 16.5/16.1, or FIA specification 8853/98.

B12.2 Fasteners Captive: Fasteners must be made captive through the use of NYLON locknuts, cottered nuts or safety wired bolts. Lock washers or thread sealants do not meet this requirement.

B12.3:Fastener Grade Requirements: Threaded fasteners utilized must meet or exceed either, SAE Grade 5, Metric Grade 8.8 and/or AN/MS specifications.

B7.3.12 Roll Cage & Bracing Materials:(B) A steel shape with bending stiffness and bending strength exceeding that of circular steel tubing with an outside diameter of 25mm (1 in.) and a wall thickness of 3 mm (0.120 in.) and a carbon content of 0.18%.The wall thickness must be at least 1.57 mm (0.062 in.).

ARTICLE 4: TOWING HITCH POINT:B4.1 :Each vehicle must have towing hitch points at the front and rear, along its longitudinal centerline.

B3.3.2 Kill Switch – Locations and Orientation (A) Cockpit Switch & B) External Switch – The external switch must be mounted on the driver’s right side of the vehicle.The Kill switch must not de-energize the Brake Light and Reverse Light.

B3.4 Brake Light:B3.4.1 The vehicle must be equipped with a red brake light that is SAE “S” or “U” rated.

B3.6 Reverse Light and Alarm: Vehicles with reverse must be equipped with a backup light marked with an SAE “R” on the lens and be equal to, or exceed the SAE standard J759.

B2.5.14 Engine Governor: GOVERNOR SETTING NOT TO EXCEED 3800 RPM.The governor spring must be placed in hole # 6.

2RULEBOOK SALIENT POINTS

VEHICLE SPECIFICATIONS

Engine-Briggs & Stratton 20S332 003DISPLACEMENT : 305 ccMAX –POWER : 10hp@3800 RPMMAX-TORQUE : 19.6 Nm @2800RPM

FrameType : Tubular space frame

Engine-Briggs & Stratton 20S332 003DISPLACEMENT : 305 ccMAX –POWER : 10hp@3800 RPMMAX-TORQUE : 19.6 Nm @2800RPM

FrameType :Tubular space frame

Baja 2015 Baja 2014

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Baja 2015 Baja 2014

Steering SystemSteering Type : Rack and Pinion

Turning Radius : 2.87m(9.4 ft)Wheel base :68”Track width :52”

Steering SystemSteering Type : Rack and Pinion

Turning Radius : 4.33m(14.21 ft)Wheel base:72”Track width:50”

Suspension Type Front RearType Double Wishbone Double WishboneShock Type FOX Air shocks FOX Air shocks Ground clearance 12 inch 11inch

Suspension Type Front RearType Double Wishbone Double WishboneShock Type Custom coil spring Custom coil springGround clearance 8 inch 8inch

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Transmission Type : Cvtech CVT(series 5600)Final drive ratio : 12.8 : 1

Transmission Type : Manual TransmissionFinal drive ratio : 19.2:1

TiresFront tire size 21/7/R10 Rear tire size 21/7/R10 Aluminum Alloy Rims

TiresFront tire size 25/8/R12 Rear tire size 25/10/R12Pressed steel Rims

Brake SystemType : Hydraulic disc brake both front and rearDisk type : 6 inch Solid disk

Brake SystemType : Hydraulic disc brake both front and rearDisk type : 8.5 inch Solid disk.

Baja 2015 Baja 2014

Target Performance Max speed :56.4kmphAcceleration :2.4m/s2

Deceleration :0.750gWeight :280kgGradeability :43˚Stopping distance :16.67 m at max speedGround clearance :11.5” Total Length :92”Total Width :58”

Performance achieved Max speed :45.kmphAcceleration :1.7m/s2

Deceleration :0.75gWeight :370kgGradeability :38ᵒStopping distance :10.61 m at max speedGround clearance :8” Total Length :89”Total Width :60”

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ROLL CAGELast Year This Year

Length : 82 inches Length: 74 inches

Width: 47 inches Width: 30 inches

Height : 50 inches Height : 50 inches

Weight : 74 kgs Weight : 36 kgs

Weld Length : 676.6 ± 23.66 inches

Weld Length: 440.12 ± 15 inches

Cockpit DimensionsCockpit Length

40 inches

Hip to Heel point

39.73 inches

Foot pedal angle

75º

Back rest angle

12º

Knee angle 133±15º

Steering Wheel dia.

12 inches

Forearm Angle 96±4º

Elbow angle 36±2º

Ergonomically designed according to 95th % Indian Male.Compact and light weight.Less Weld Length.Percentage weight reduced-51.35%.Use of bending of tubes.

BAJA 2014 BAJA 2015

Reference from 61517181-Indian Anthropometric Dimensions by Mr. Debkhmar Chakrabarti

Ergonomical Data6

Frame Designing

and modeling

Failed

/Low

factor

of sa

fety

TUBE SELECTION

Last Year Problems Faced This Year Improvements

Material : AISI 1030 Yield strength 440 Mpa.

Too heavy. Material : AISI 4130Yield strength 460 MPa.

More yield strength at same density and weight.

Crossection : Primary and Secondary both 1inch OD and 3mm wall thickness

More than required strength of roll cage, more weight.

Crossection:Primary 1.25inch and 2mm thicknessSecondary 1.25inch and 1mm thickness

11.5% weight reduction in primary member.63.7% weight reduction in secondary member.

Bending Strength of 467.164 Nm.

Bending strength per unit mass is lesser.

Bending strength 602.18 Nm.

28.90 % more bending strength.

Design Methodology: Rulebook constraints

Study of Ergonomics

Tube Selection

Considerations and

Calculations

Finite Element Analysis

Iterations to accommodate

other sub-assemblies

PassedFinal Design

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Front Head on collision @ force of 2450 N.200.2 Mpa max Stress induced Factor of safety 2.29

Rear impact by another vehicle @ force of 1600 N.237.72 Mpa max Stress induced Factor of safety 1.93

Side collision @ force of 1600 N.157.69 Mpa max Stress induced Factor of safety 2.91

Roll over impact @ force of 4212.01 N.202.89 Mpa max Stress induced Factor of safety 2.29

8FINITE ELEMENT ANALYSIS

DESIGN CONSIDERATIONS

1. WHEELTRACK, WHEELBASE.

3. GROUND CLEARANCE,ROLL CENTER, ROLL AXIS.

2. WHEEL GEOMETRY i.e. TOE, CAMBER, CASTER, KPI.

4. MOTION RATIO, WHEEL TRAVEL, SHOCK TRAVEL,

SPRING RATE etc.

5. DOUBLE WISHBONE GEOMETRY AND FEA

SUSPENSIONFRONT GEOMETRY REAR GEOMETRY

TARGETS:•High Performance.•Effective Ride & Handling.•Improved Stability.•Optimum Comfort Levels.

BASIC GEOMETRY CALCULATIONS

PARAMETER FRONT REAR

CAMBER -1.5 degree 0 degree

TOE 1/16 “ 0 “

LOWER A-ARMS 16.01” 17.1”

UPPER A-ARMS 16.07” 15.88”

MOTION RATIO 0.7 0.65

SHOCK TRAVEL and SHOCK ANGLE

12”23° from vertical

8.5”30° from vertical

WHEEL TRAVEL 10.07”(Bump)5.7”(Droop)

7.74”(Bump)3.58”(Droop)

KPI +8 Degrees +8 Degrees

CASTOR +5 Degrees +0 Degrees

SCRUB RADIUS 50mm 55mm

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SUSPENSIONPARAMETER PROBLEMS (BAJA 2014) IMPROVEMENT (BAJA 2015)

FRONT and REAR UPPER ARMS

• Fixed Length, wheel geometry non adjustable.

• Less strength to weight ratio (AISI 1030)

• Adjustable Wheel Geometry.• AISI 4130, More strength to weight ratio • Skewed Pivot Type with Heim Joint

FRONT and REAR SHOCK ABSORBERS

COIL SPRING: Fixed spring rate, preload and damping rate

FOX AIR SHOCK: Infinite Spring Rate, Adjustable Rebound and Compression Rate

REAR WHEEL TRAVEL

Short A-Arms(6”), Half Shaft’s angle High Longer A-arms(around 16”), More shock travel, Small angle of Half shaft

SIMULATION ON SUSPENSION ANALYZER

REAR LOWER A-ARM FOS=3.07 for Single wheel

landing.

MAX DISPLACEMENT=0.376 mm

MAX VON MISSES STRESS INDUCED = 150 MPa

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STEERINGObjectives :•Promote straight line stability. •Reduce the net unsprung mass.

•Provide quick return to steering mechanism. •Reduce the minimum turning radius.

11•Minimize tire wear.•Provide better ride quality.

Last Year This YearSide mounted Rack and Pinion of steering ratio 17:1. Number of turns required to rotate the wheel from lock to lock = 3.2U-V joint was used to make the system centrally aligned and thus the net steering effort required was increased.

Centre mounted Rack and Pinion of steering ratio of 12:1 and of end to end length of 14”.The number of turns required to move the steering wheel from lock to lock is 1.5 with rack travel of 4.25 “.

Modified Maruti 800 Steering Knuckle was used both at front and rear which weighed 2.55 kgs.

Custom made Knuckle will be used. The rear knuckle weighs 0.495 kgs and the front knuckle weighs 0.835kgs.

The Unsprung mass contributed by the steering knuckles was 10.2 kgs.

The unsprung mass is reduced by 7.56 kgs i.e. 74% weight reduction contributed by knuckle.

The rear knuckle required a toe link. No toe link required at the rear knuckle.

Last year the knuckle used was in front configuration and so the safety was a concern to the front impact.

This year Steering knuckle in reverse configuration will be used which ensures more protection to steering arm.

Design Considerations for Steering Mechanism :A centre mounted Rack and Pinion is chosen because of its high feedback and less steering effort requirement. Its positioning, tie rod sleeve length and angle is decided according to : •Avoidance of Bump Steer•Ackermann Geometry

Turning Radius = 2.87 meters( 9.4 feet) Lock to lock angles : Outer Wheel = 26 degrees Inner Wheel : 36 degrees.

Front Knuckle Rear Knuckle

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The Design of knuckle is based on following parameters and dimensions :King pin InclinationCaster Angle

Calliper Mounts DistanceBearing Outer Diameter

Bump SteerAckermann geometry

The designing and FEA is done on Solidworks . The Material used is Aluminium 6061 – T6(SS) of Yield Strength 275 MPa.

Front Knuckle

von Mises Stress = 69.6 Mpa

Max. Deflection = 0.023 mm

Min. FOS = 3.96

Rear Knuckle

von Mises Stress = 95.1 Mpa

Max. Deflection = 0.035 mm

Min. FOS = 2.89

BRAKING

Previous years vehicle

This years vehicle

Maruti rotor - 2.5 kg Custom made rotor - 150gm.

Maruti hub - 2.2 kg Custom made hub- approx. 1kg

Maruti calliper -3.75 kg approx.

LML Euro 200 Geared Scooter calliper - approx 600 gm

Pedal ratio - 4:1 Pedal ratio - 6.2:1

Total Weight- 30 Kg Total Weight- 9 Kg(70% Weight Reduction)

Previous year the braking achieved was sufficiently high but the only drawback was the excess weight of the brake assembly. So our main target is overall weight reduction of the brake assembly which has been shown in the subsequent table.

Design Considerations:

Total Weight

Brake Force Developed

Heat Flux Induced

Pedal Force 375 N

Pedal Ratio 6.2 : 1

Dia Master Cylinder 2 cm

Dia Calliper Piston 2.54 cm

Brake torque generated 245 Nm

Maximum deceleration 0.75g

Stopping distance 16.67 m at max speed

Weight transfer 60:40

Braking Specification

While Braking

0 10 20 30 40 50 60 700

5

10

15

20 56.4 16.6750, 13.1

40, 8.38830, 4.71

20, 2.097

10, 0.5243

Stop

ping

Dis

tanc

e(m

)

Speed (km/hr)

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Material Factor of safety Weight

Grey Cast Iron 4.3 350g

AISI 316 Stainless Steel

4.67 390g

Aluminium 6061 T-6 6.218 130g

Conclusion: Best material for rotor and hub after analysis is Aluminium 6061 T-6

Max Von-Mises Stress induced in rotor while braking, 45.02 Mpa

Structural analysis of rotor gave 6.21 Minimum Factor of Safety.

Max Von-Mises Stress induced in Hub 63.922 Mpa

Structural analysis of hub gave minimum Factor of Safety 3.911

Thermal analysis of rotor while braking.

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POWER TRAINBaja 2015 Drive Train

• 10hp Briggs and Stratton OHV Intek engine coupled with IBC-Cvtech CVT.

• chain & sprocket drive system.• Customised Mahindra Alfa Differential.

Drawbacks of Last years vehicle Improvements in this years vehicle

Manual transmission has lower Fuel Efficiency. By using properly calibrated CVT we will increase the fuel efficiency.

Manual shifting, lack of driver’s focus, unwanted shifting of gears due to vibrations and mud during endurance.

Automatic shifting of gears enhancing driver’s focus on driving.

Low Torque Output, higher losses in transaxle and low power to weight ratio.

High Torque Output (calibrated drive ratios) and better power to weight ratio.

Max gradeability of 38º Improved Max gradeability to 43º

Lack of design validation resulting in unequal lengths of the half-shafts and mismanagement of engine compartment space.

Proper design validation and CAD modelling accommodating the entire drive train within a defined space.

Top Speed 42 km/hr and Acceleration 1.7 m/s2. Increased Top Speed 56 km/hr and Acceleration 2.44 m/s2

Continuous load led to overheating of clutch plates. CVT and chain drive with specialized focused-air cooling system will be used.

Total weight of transmission 26 kg. Weight reduced to approximately 18 Kg.

DESIGN CONSIDERATIONS:1. Achieve Better Acceleration, Top Speed, Manoeuvrability, Gradeability.2. Achieve Better Fuel-Efficiency.3. Proper Design Validation and Analysis of all the Components Manufactured, Customized or Procured.4. Overcome all the Issues and Limitations faced in previous year and major improvements in each aspect.

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CVT under drive ratio 3.5:1

CVT over drive ratio 0.5:1

Chain Sprocket ratio 3.07:1

Differential ratio 4.17:1

Final drive ratio 12.8:1

Important Calculations and data regarding drive train

Top speed (at 3600 rpm)

56 km/ hr

Average acceleration 2.44 m/s2

Gradeability 43º

Torque at wheels ( at 2800 rpm)

355 N-m

Tractive factor ( at 2800 rpm)

0.453

Larger Sprocket FEA with maximum stress induced 50.8 Mpa and FOS 12.2

Smaller Sprocket FEA with max stress induced 109 Mpa and FOS 4.2

Diameter of smaller sprocket

2.1”

Diameter of larger sprocket

6.4”

Chain type Pitch 12.7 mmNo.420

Center to Center distance

7”

Chain and sprocket reduction specs

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Design layout for 2015 Baja Vehicle

DESIGN VALIDATION

Roll-Cage Drivetrain Braking Suspension Steering MiscellaneousRevised

Calculations & Considerations.

Revised Strength calculations of

Sprocket and chain drive.

Revised calculations and considerations.

A Arms consideration,

calculations and Finite Element

Analysis.

Design calculations,

considerations and Finite element

Analysis.

Weight check after fabrication

on a scale.

Destructive testing of weld joints/Buckling test on UTM.

Finite Elements of sprockets and chain

Analysis using ANSYS.

Strength and Thermal analysis

on ANSYS & FOS kept above 3.

Destructive testing and

strength test of A arms on UTM.

Turning radius, lock to lock angle

check by measurement.

Electronics check with and

without kill switch pushed

off.

Jigs and fixtures to get accurate

angles.

Drive testing for acceleration, max

speed, and greadability.

Panic brake testing by checking wheels

lock.

Ground clearance and shock travel

check by measurement.

Camber and toe check by wheel alignment test.

Kill switch testing by

stopping engine by kill switch.

Vehicle simulation and

FEA using ANSYS.

Oil and other fluid leakages while

climbing a grade

Leakage checks in brake lines.

Fixtures for the accuracy of angles

of A arms.

Tie rod angle and rack position check

to avoid bump steer.

Driver exit time check.

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Failure Cause of Failure

Effect Actions Taken O S D RPN

Frame Poor calculations.

Failure of structural integrity of vehicle.

Ext. research of forces on frame & to get F.O.S

above 2.

9 10

1 90

Frame Degraded quality of

tubing material

Failure of structural integrity of vehicle

Market research & Material Testing on UTM

& BHN.

7 10

2 140

Braking System

Improper Pipe Connection, Air

Intrusion

Improper Brake Force Generation,

Brake Fade

Appropriate Linkage Design & Proper Brake

Bleeding

8 7 2 112

Braking System

Overheating of Discs

Insufficient Venting, Good material for the disc with better heat

dissipation.

2 7 3 42

Cvt Breaking of belt Inability to operate High F.O.S 4 2 4 32Chain sprocket Unprotected drive Chain wear & Teeth wear Selection of Chain. 3 2 3 18

Steering Knuckle

Fluctuating Dynamic Stresses

Vehicle Unstable FEA with high FOS 2 10

5 100

Rack Mounting

Excessive Dynamic Forces

Leads to Serious Accidents

Use of proper Clamps & Fasteners

3 10

2 60

Ball Joint Improper Wheel Geometry &

Fitting

Vehicle Unstable Tapered Hole in Knuckle & Including Ball Joint

Sleeve

2 10

7 140

Shock Bracket & Arm Bracket

5G Loading Unstable + Wheel Detached

FEA 4 10

4 160

A-Arms Tube Bending

5G Loading Minor Changes in Wheel Geometry

AISI4130-High Strength 2 6 8 96

18DESIGN FAILURE MODE EFFECT ANALYSIS

0100000200000300000

(In

Lac

s) 1.5 Lacs2 Lacs

Weight Distribution

3Lacs

Funds from College

Collection from Team Members

Sponsorship

COST EVALUATION

19FINANCING OF PROJECT

Total Cost : 5,72,000Total Weight: 185Kg (Excuding Driver and Fluids)

ECM/BCM Work Allocated

T Mani Teja Safety Equipments +

FabricationVivek Kr

ChoudharyElectricals + Fabrication

Roll Cage Work Allocated

Gagan Dhawan

CAD Modeling + Fabrication

Palash Kaushik

Finite Element Analysis + Fabrication

Rishabh Kakkar

Tube Selection+ Fabrication

Kunal Gautam Ergonomics study

Braking Work Allocated

T Mani Teja FEA + Fabrication

Rituraj Jangid Calculations+ Fabrication

Ashish Krishna Market researchVivek Kr.

ChoudharyMaterial

Analysis+ Fabrication

Ankit Sharma CAD Modeling

Suspension Work Allocated

Amal George CAD Modeling + Fabrication

Saarthak Gupta

FEA + Fabrication

Anubhav Bansal

Calculations + Fabrication

Pranay Agrawal

Market Research

Power Train

Work Allocated

Vardaan Bhatia FEA + FabricationPrashant

GuptaCalculations +

FabricationAmanpreet

SinghCAD Modeling

Krishan Vallabh

Market Research

Pushkar Pandey

Transmission Selection

Steering Work Allocated

Saarthak Gupta

CAD Modeling + Fabrication

Deepak Kukreja

Market Research + Fabrication

Pankaj Verma FEAYatendra

SinghCalculations

Tire & Wheels

Work Allocated

Tejash Raj Tire Selection + Fabrication

Varun Chandiok

Rim SelectionGo-Green Work AllocatedGurpreet Marwah

Theoretical Research + Fabrication

Drishtant Sharma

Market Research

20TEAM COMPOSITION AND WORK ALLOCATION

Miscellaneous Work Allocated

Deepak Kukreja Sponsorship Head

Varun Chandiok Marketing Head

Rishabh Kakkar Finance handling

Tejash Raj Treasurer

Anubhav Bansal Quality Check Head

Faculty Advisors

Mr. Deepak Sharma

Mr. Urfi Khan

COLLEGE WORKSHOP FACILITIES

MIG MAG WELDING MACHINE

PRECISION LATHECNC LATHE

POWER SHEAR

UNIVERSAL TESTING MACHINE

HYDRAULIC PRESS

CNC TURNING

SHAPER

SLOTTER

DRILLING MACHINE

CNC VERTICAL MILLING

CNC WIRE CUTTER

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