design report cyclotron 33

8/11/2019 Design Report Cyclotron 33

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Effi-cycle SAENIS 2012Design Report

Team Name Cyclotron

Team Number 33

College Name Rajalakshmi Institute of Technology

City Chennai, Tamilnadu

Author M. Karthikeyan

[email protected]

Co-Author G. Amit Kumar

[email protected]


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ABSTRACT

In regard to the recent surge of development in the automotive industry, and the growing need for

alternative energy source for mobility in the day to day scenario, this project carried under SAENIS-

Effi-cycle aims at providing an energy efficient human powered three wheeled electric vehicle

capable of carrying two passengers.All the features like drivetrain, KERS,suspension,brakes,steeringand frame structure has been designed to comply with the requirements specified by SAENIS Effi-

cycle rulebook.

The tri-cycle possesses a unique frame structure, designed for maximum stability, maneuverability

and safety of the passengers. It consists of a tad-pole configuration and independent steering which

provides maximum driver control and least turning radius. The pentagonal shaped section in the frame

is designed for optimum space utilization for housing the motor and KERS system.The mechanical

KERS uses a completely new technology complying with the 'GO GREEN!' approach and

facilitating a boost of energy at the driver's will. The drivetrain comprises 5 free-wheel sprockets for

combining the power obtained from the two passengers, KERS and motor and transfers it to the rear

wheel.

A literature survey before the design phase, allowed us to determine the basic raw materials required,

the dimensional tolerances, and the processes for manufacturing. In order to optimize the

manufacturing cost and make it commercially viable, the concept of DFM (design for manufacturing)

was utilized. The FMEA (Failure mode and effect analysis) enabled us to fix the potential problems in

the design phase itself. Hence a commercially feasible and 'production ready' vehicle was generated.


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TECHNICAL SPECIFICATION

Overall dimensions: 2159mm X 1143mm X 1914 mm

Weight: Gross weight- 289 kg Kerb weight- 59 kg

Vehicleconfiguration

Tadpole configuration

Chassis structureRectangular box section chassis with pentagonal framework for mounting motor,seat and KERS

Power -PMDC Motor, 400W, 24V-Pedal driven

Steering Type : Ackermann Steering, Split handlebarTurning Radius : 2.25 m

SeatingFront-Ergonomic seatRear-Adjustable seat

Suspension

Rear: Coil spring with telescopic shock absorber.

Stroke Length = 5 cmFront : Coil springStroke Length = 12 cm

BrakesFront : Mechanical disc brake

Rear : Hand operated shoe brake

WheelsFront Wheel diameter : 24 inch

Rear Wheel diameter : 26 inch

ElectricalsBattery-12V (2Nos) , connected in seriesHeadlight ,Tail light, Indicators, Horn, Motor-accelerometer

Safety Independent kill switches for both driver, roll-over cage , front bumper

Additional

features

-Mechanical KERS systemspiral torsion spring for energy storage(engaged anddisengaged according to need)

-Dashboard

PERFORMANCE TARGETS

The key performance criteria are:

1. Vehicle configuration- Three wheel not in straight line and capable of carrying two riders with a

maximum vehicle dimension of 90inch x 50 inch.

2. Seating arrangement- Maximum seating height limited to 36 inches &rider height up to 190.3 cm.

3. Chassis structure- Must be made up of steel and a minimum diameter of 1 inch.

4. Load character- Weight of rider 115 kg + PMDC/BLDC motor

5. Brakes- Positive locking brakes on all wheels, hydraulic/non-hydraulic brakes, must be mounted on

the wheel and not on drive axle.

6. Power- must be driven by both humans in addition to electric power.

7. Safety- : Kill switch should be accessible to both riders. Vehicle to consist of roll-over protectionand frontal impact protection.


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DESIGN CALCULATIONS

Brakes

Co-efficient of friction on pedal = 0.3, Force on brake handle =200 N, Radius of disc = 80 mm

M.AMechanical Advantage = 3:1, Wheel Radius = 304.8 mm

Braking torque = 2 x F x R x = 9600 Nmm

Frictional Braking torque = 28800 Nmm

Braking force = Frictional Braking Torque / Wheel Radius = 94.48 N

Deceleration rate = Braking Force / Vehicle Weight= 0.2140 m/s2

Assume 0.4g acceleration,

Stopping Distance = Velocity / 0.4(v = 20 km/hr) = 5.55 m

Steering

Force Required = 1000 N x 0.3 (co-efficient of road surface)

Force applied by driver = 30 N

Leverage ratio = 12:1

Transmission efficiency = 0.9

Compressive force = PL / AE

360 = 300 x l / A x 2x10^5

A = 2.708 x 10^ -3 mm2

d = 12.7 mm, Turning circle radius = 2.5m

Suspension

Modulus of rigidity0.85 x N/, Free length = 310 mm, Solid length = 260 mm, Mean coil

diameter (D) = 70 mm, Outer diameter of the spring = 70 mm

To find the wire diameter and pitch of the spring,

Deflection (y) = = 310260 = 50 mm

Also y = (8 x P x x n1) / G x d4

Load (P) = 1500 N, n = n1 + 2 (squared and rounded)

n1 = 9, d = 9.66 mm

= pn + 3d Pitch = 25.54 mm


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Motor Power

Driving force calculations:

Gross vehicle weight, w = 270kg=2648.7N, Maximum vehicle speed, v = 20 km/hr = 5.55m/s

Acceleration: (assume 20km/hr in 20 seconds) a = v/20 =0.2775m/s2

External driving force, E.D.F = gross vehicle weight acceleration = 74.79N

Resistance calculations:

Air resistance:

Ra= 0.0386**Cw*A*(v + vo)

- Density of air = 1.23 kg/m, Cw- Drag co-efficient= 0.4, Frontal area= 1.287m, Vo- Wind speed=0

Ra = 8.07126N

Rolling resistance:

Rr= f*m*g* cos d

f- co-efficient of rolling resistance= 0.007, d=0

Rr==18.5409N

Power due to rolling resistance =205.98W

Case 1: when running on manual power (assume speed=20Km/hr)

S=ut+1/2*at2

S=55.4m

Work done = F*s = 4143.366 Nm

Power output = Work done/Time taken = 207.91W

Case 2: When running on motor (let speed be 40km/hr)

S=ut+1/2*at2

S=221.6m

Work done = F*s = 16573.464 Nm

Power output = Work done/Time taken = 414.33W

Total power = 205+414+27.67 = 647.57W


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ERGONOMICS

One of the key parameters around which the vehicle was designed is driver ergonomics and passenger

comfort. The following are the design features that reflect it:

Comfort - The driver seat is ergonomically designed for maximum comfort. The rear seat is

also 'slider adjustable' according to the comfort of the pillion driver.

Occupant packaging - The pillion driver seat is placed at a height in order to provide an

unobstructed vision. The placement of the passengers is such that there is ample clearance

from any moving parts.

Safety -The frame is designed in such a way that in case of roll-over, frontal or side impact,

the driver and passenger are protected from the crash.

Ease of use - The vehicle features a dashboard which provides controls to KERS, lights etc to

the driver.

Aesthetics - The tadpole configuration adds an aesthetic appeal to the entire vehicle structure.

The headlights and taillights add a refined look to the vehicle.

RECYCLABILITY AND GO GREEN APPROACH

The primary purpose behind the design and fabrication of the vehicle was to go in sync with the 'GO

GREEN' anthem.

I. The concept of 'Reuse, Reduce, and Recyclewas appropriately applied during the fabrication

process as all the materials used in the frame are recyclable. The frame also sports few resale parts

hence absorbing the concept of 'reuse'.

II. Since the drivetrain is a combination of pedal drive and motor driven, this hybrid technology is

pollution free and supports the environment.

III. The key feature and innovation in the design is the KERS (mechanical) which transforms the lost

energy during braking into useful energy which can be used at the driver's will.

INNOVATION

KINETIC ENERGY RECOVERY SYSTEM

The KERS system is housed in an independent shaft parallel to the drive shaft. There are twosprockets each on the two shafts which are connected via chain. The KERS shaft consists of an

epicyclic gear train, brake with brake calipers and torsion spring


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.

During normal running condition, the drive shaft rotates the KERS shaft through the sprockets in

clockwise direction. This is in turn rotates the sun gear in clockwise direction which makes the planet

gears rotate in anti-clockwise direction. The ring gear remains stationary.

During braking condition, when the brakes are applied the sun gear is made stationary and the ring

gear in turn rotates in the anti-clockwise direction. Since the ring gear is connected to the torsion

spring, the spring is wind in the anti-clockwise direction. When the brakes are released the torsion

spring unwinds and transmits this clockwise rotation to the drive shaft. Therefore the energy which is

otherwise lost during braking is regained

DESIGN DIFFERENCES FROM LAST YEAR

There are monumental changes in the design when compared to last year. The key differences are:

I. Frame/Chassis - This year's frame is a completely new design built from scratch. The new frame

sports a ladder type structure which optimizes between occupant packaging, aesthetic appeal and

safety.

II. Drivetrain - The new transverse drivetrain shaft consists of five free-wheel sprockets that are

required to combine the power from two drivers, the motor and the KERS and push the resultant to

the rear wheel.

III. KERS - The Kinetic energy recovery system is an added feature which was not used last year.

IV. Safety - Unlike last year, this new design possess a roll-cage for roll-over protection and front

bumper for frontal protection.

V. Steering - Unlike last year, this year's design possess an independent steering with split handle bar

for increased maneuverability.

RESOURCES UTILISED

I. Design phase: The SOLIDWORKS CAD software was used for modeling all the components and

generating the drawing views.

II. Analysis phase: The frame analysis was carried out using ANSYS CAE package.

III. Manufacturing phase: Workshop tools required for the welding, milling, cutting, drilling and

machining operations were used.


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PROJECT PLAN

Phase Dates Work scheduled

1. 30 July to 5 Aug Material Purchase

2. 6 Aug to 12 Aug Fabrication of chassis

3. 13 Aug to 19 Aug Fabrication of Steering Parts

4. 19 Aug to 21 Aug Assembly of steering system

5. 22 Aug to 26 Aug Fabrication of Transmission System

6. 27 Aug to 2 Sept Assembly of Transmission System

7. 3 Sept to 9 Aug Fabrication and Assembly of Mechanical KERS

8. 10 Sept to 16 Sept Full Body Assembly including the Wheel9. 17 Sept to 23 Sept Connections of Brakes and Electric power source

10. 24 Sept to 30 Sept Aerodynamics and Finishing

11. 1 Oct to 7 Oct Test Driving and trouble shooting

Target date of completion-7/10/12

DESIGN VALIDATION PLAN

In order to ensure that 'design meets requirements' and to reduce the manufacturing cost the following

technique were applied:

I. Literature survey and Market survey- It provided a deeper understanding of the need &

requirements and then generates a commercially viable solution complying with the required

standards.

II. Risk management- The potential problems were discovered and mitigated during the design phase

itself using FMEA tool.

III.Design analysis- The generated design were tested using ANSYS software for load and stress

pattern

COST REPORT SUMMARY

Subassembly name Procurement cost(Rs) Manufacturing cost(Rs)

Frame 3667.5 3256

Drivetrain and KERS 18349 416

Suspension 4795 478

Wheels and Brakes 2175 -

Steering 1021.25 530.7

Total cost: Rs.34688.45


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REFERENCE AND ACKNOWLEDGEMENT

We would like to thank SAENIS for providing a platform to pursue such engineering maneuver. We

would also like to extend our sincere gratitude to our college for assisting us with workshop

technology. We would also like to thank our parents for encouraging us to pursue this project.

References:

-www.google.com

-www.wikipedia.com

-www.howstuffworks.com

-Machine Drawings by N.D.Butt

-Production technology by Hajrachowdry

-Material sciences by O.P.Khanna

-Automotive engineering by Kirpalsingh

-Automotive engineering fundamentals by Richard Stone & Jeffery ball

-Automotive engineering chassis system and vehicle body by David Crolla

TEAM STRUCTURE

TEAM MEMBER WORK ALLOTED

Mr. Janakiraman Faculty Advisor

G.Amit Kumar Design and analysis

M .Karthikeyan Frame structure welding and assembly

K. Shanmugaraj Frame structure welding and assembly

S. Anand ram Drivetrain and KERS

M.S. Karthigeyan Steering

L. Mohan Kumar Brakes and assembly

C.G. Dhatheshvar Suspension

M. Maharaja Mariappan Electricals


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CAD MODEL

FRAME (Actual and 3D)

DRIVETRAIN (Actual and 3D)


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FEA SIMULATION

FRONTAL IMPACT

SIDE IMPACT

Equivalent stress Deformation

Equivalent stress Deformation

The maximum equivalent stress is 2329.2 MPa.

The total deformation is 30.1 mm.

The maximum equivalent stress is 1689MPa.



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ROLL-OVER

E uivalent stressDeformation

The maximum equivalent stress is 4176.8 MPa.


design report cyclotron 33

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