baja buggy technical details

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BAJA SAE INDIA 2014 VIRTUAL ROUND TEAM VIKRAM Babu Banarasi Das National Institute of Technology & Management Lucknow , Uttar Pradesh Northern Section

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Page 1: Baja Buggy Technical Details

BAJA SAE INDIA 2014VIRTUAL ROUND

TEAM VIKRAMBabu Banarasi Das National Institute of

Technology & ManagementLucknow , Uttar Pradesh

Northern Section

Page 2: Baja Buggy Technical Details

TEAM LEADER

DESIGN & ANALYSIS TEAM

SteeringRoll cage

Suspension

MANUFACTURING TEAM FINANCE

Fabrication

Parts Procurement

Jigs & Fixtures Brakes

Budgeting & Cost Estimations

Market Survey

Marketing and PR

Transmission Engine & Electricals

Modeling & Simulation

SPONSORSHIP

Ergonomics & Aesthetics

TEAM FORMULATION

TEAM SIZE :- 25 MEMBERSDesign Input by: BAJASAE 2014 Rulebook

Modelling on: PRO-E WILDFIRE 5.0FEA Constraints formulation on : ANSYS 14.5 & ALTAIR HYPERWORKS

Page 3: Baja Buggy Technical Details

Technical Specifications Parameter Value

Vehicle length 2500 mm

Vehicle width 1556.4 +00+50 mm

Ground clearance 254 mm

Vehicle height 1534.25 mm

Roll cage material Carbon Steel(AISI 1018)

Tube dimension 25.4 mm outer dia.3mm inner dia.

Roll cage mass 22 kg

Total mass 350 kg approx.

Parameter ValueBattery 12V/44 Ah

SuspensionFront Rear

DoubleWishbone

DoubleWishbone

Damper mounting Lower arm

Upper arm

Max speed 58 km/h

BrakeFront Rear

Disc Disc

Steering Rack and pinion

Tyres 22 X 8 - 10

Page 4: Baja Buggy Technical Details

Roll CageDesign Methodolgy:• Driver oriented rollcage design.• Light weight, compact and simple.• Ease of egress during accident.• Members are kept short by optimum triangulation to have a good load transfer path.• Frame is designed to be stiff for loads like bending and torsional.• Material is kept farther from rotating axis to increase stiffness.• Polar moment of inertia is maximised.

Total number of weld joints: 48

Width of Rollcage: 750 mmLength of Rollcage: 2500 mmHeight of Rollcage: 1280.25 mm

Material Used: Carbon Steel (AISI 1018)• UTS: 365 Mpa• Carbon content: 0.18%• Outer Diameter: 25.4mm• Wall Thickness: 3mm (primary members) 0.89mm(secondary members)

Page 5: Baja Buggy Technical Details

Devised Plan for Finite Element Analysis

INITIAL DESIGN FINAL DESIGN

CONSTRAINTSREAR CORNERS(ALL DOF=0);SUSPENSIONMOUNTINGS(Uy,Uz=0)

OPPOSITE SIM MEMBERS(ALL DOF=0)

LFS MEMBERS (ALL DOF=0)

FRONT CORNERS(ALL DOF=0); SUSPENSIONMOUNTINGS(Uy,Uz=0)

LOADS 5G 3G 2.5G 4G

TESTS FRONT IMPACT SIDE IMPACT ROLL OVER REAR IMPACT

FACTOR OF SAFETY: ALWAYS CONSIDERED FOR THIS DESIGN BETWEEN 1.5 - 4

CONSIDERATION FOR MESHING: Tria elements are considered below 5% for meshing.Warpage below 7O . Jacobian ratio kept around 1. Aspect ratio is kept less than 7.

Page 6: Baja Buggy Technical Details

SteeringThe steering system allows the driver to control the direction of vehicle travel. This is made possible by linkage that connects the steering wheel to the steerable wheels and tires.

Types of steering:1.Recirculating ball steering gear2.Rack and pinion gear3.Worm and Sector We are using the Rack and Pinion gear system.

Design selection criteria:We are using the rack and pinion gear system just because due to its low cost, its better compatibility with our compact design and its simple construction. We are using the manual steering system, so it will help us for immediate response.CALCULATIONS :Wheel base - 1800mmTrack width - 1250mmLock to lock ratio - 3Steering ratio - 16:1Ideal Ackerman angle - 19.15Actual Ackerman angle- 7.660

Inner angle(i) – 37.590

Outer angle(o)- 29.93o

Turning Radius- 2963mm Caster- 5o negativeCamber- 2o positive

Page 7: Baja Buggy Technical Details

Braking System

• The brake system consists of four wheel disc brakes actuated by two independent master cylinders. The brake pedal uses a 6.2:1 pedal ratio .

• The brake callipers chosen are single piston floating type callipers of Honda Aviator and Bajaj Pulsar220 .

• DOT 4 brake fluid will be used for braking purpose

SpecificationsPedal ratio = 6.2:1Pedal size = 7.75”Braking percentage = 62:38Master cylinder type: Two random master cylinders of Maruti 800 and a balance bar.Brake lines: maruti 800 brake lines and hosesCalliper type: single piston floating-type callipers of Honda Aviator and Bajaj Pulsar 220Calliper cup size = 1.5”Rotor type: ventilatedRotor size = 7.48”(190 mm )Rotor thickness = 4mm

Page 8: Baja Buggy Technical Details

f = 7.84m/s2Rf = 2121.45N and Rr = 1308.54N. this will be the front wheel and rear wheel reactions.

after a hard braking on level track, producing a deceleration of 6.87 m/s2

• STOPING DISTANCE

SPEED (Km/Hr)

Stopping Distance(m)

Braking Time(s)

30 4.42 1.06

40 7.87 1.42

50 12.30 1.78

58 16.55 2.05

Page 9: Baja Buggy Technical Details

Ergonomics & Safety Features Ergonomics refers to the relationship between people and their working environment, so in our vehicle the perspective of ergonomics has been considered over 4 points:1. Vision 2. Ease of egress3. Additional Controls

Page 10: Baja Buggy Technical Details

POWER TRAIN TRANSMISSIONManual transmission needed gear shift which would require some area near driver seat and thus increases the dimension of buggy. So we decided to go for cvt transmission.Pulley based CVT is the most affordable and simple one. It consist of two pulleys.primary pulley connected to engine and secondary pulley connected to axle.These two pulleys are connected by a rubber V belt. Variation in the pitch radii of these pulleys lead to the change in the gear ratio.

CVT Transmission option available :1.Mahindra alfa cvt.2.Polaris p90 cvt.

We are opting Mahindra ALFA because of its well known coupling with B&S Engine and its low cost.

Power train refers to the group of components that generate power and deliver it to the wheels of vehicle.

ENGINE SPECIFICATIONSTorque 14.50 ft-lbsDisplacement 305

No. of cylinder Single

Configuration Horizontal

Technology OHV

Length 12.3 in

Width 15.4 in

Height 16.4 in

Weight 50.4 lbs

Bore 3.12 in

Stroke 2.4 in

Engine Fuel Gasoline

Spark Plug RC12YC

Page 11: Baja Buggy Technical Details

SuspensionDesign Criteria:Both the front and rear suspension system are independent double wishbone(A-arm) suspension having unequal control arms. It is chosen because 1: Wishbone suspension give more movement of the tires and hence the vehicle.2: In double A-arm suspension, force is distributed at five points on the roll cage unlike at only one point in macpherson strut.3: It can be slightly adjusted for different parameters of suspension tuning like chamber angle, ground clearance etc.

The A-arms at the front are pinned to the roll cage while at the knuckle end the arms are attached using boll and socket joints. While at the rear as there is no cornering requirement the A-arms are pinned both to the roll cage as well as the knuckle.

FRONT LOWER CONTROL ARMSLENGTH: 280 mm

REAR UPPER CONTROL ARMS

LENGTH: 190 mm

Page 12: Baja Buggy Technical Details

Design Validation Plan

Page 13: Baja Buggy Technical Details

DESIGN MODE AND FAILURE EFFECT ANALYSIS

Page 14: Baja Buggy Technical Details

COLLEGE FACILITIES

Centre latheMillingPipe bendingElectric arc weldingOxy-Acetylene WeldingDrilling machineShaper machinePower hack sawPortable drilling machinePlaner Machine

35%

11%

2%

8%7%

6%

2%

13%

17%

PIE CHARTENGINE & DRIVE TRANSMISSION STEERING SUSPENSIONFRAME & BODY BRAKES ELECTRICAL SAFETYMISCELLANEOUS

SUBSYSTEM MATERIALS EXTRAS TOTAL

ENGINE & DRIVE 70,000 - Rs. 70,000

TRANSMISSION 22,700 150 Rs. 22,850

STEERING 2,500 1,000 Rs. 3,500

SUSPENSION 11,000 4,500 Rs. 15,500

FRAME & BODY 9,000 5,000 Rs. 14,000

BRAKES 10,000 1,580 Rs. 11,580

ELECTRICAL 4,370 - Rs. 4,370

SAFETY EQUIPMENT 25,890 - Rs. 25,890

MISCELLANEOUS - - Rs. 33,500

TOTAL Rs. 2,01,190

Cost Estimation

Processes in sequence of: Pipe Cutting Bending Welding Inspection Undercoating Drawing Baking Painting

Then the roll cage is assembled with: 1.TYRES, DAMPERS AND SUSPENSION 2.ENGINE SYSTEM 3.STEERING AND BRAKES 4.DRIVER SEATPADDING5.TRANSMISSION SYSTEM

MANUFACTURING PROCESSES REQUIRED

Page 15: Baja Buggy Technical Details

THANK YOU!