Upload
saurabh-kumar
View
7
Download
3
Embed Size (px)
Citation preview
Dr. M.G.R.EDUCATIONAL AND RESEARCH INSTITUTE
UNIVERSITY(Decl. Under Sec. 3 of UGC Act – 1956)
VIRTUAL SUPRA SAE INDIA 2010
TEAM GARUDA ULTIMATE
The SUPRA SAEINDIA 2011 competition challenges teams of university undergraduate and graduate students to conceive, design, fabricate and compete with their own small formula style autocross racing cars. For the purpose of this competition , the students need to assume that a manufacturing firm has engaged them to design, fabricate and demonstrate a prototype car for evaluation of the same as a product ready for production.
The vehicle should meet all the safety parameters as per the rule book. The use of Maruti 800 BS 3 engine is mandatory. The vehicle must be open-wheeled and open cockpit ( a formula style body). Minimum wheelbase allowed is 60 inches. Vehicle track must be no less than 75%of the larger track. Minimum ground clearance- 1 inch Vehicle must have inspection holes and all suspension points should be visible. Braking and steer-by wire is prohibited. Total usable wheel travel of at least 2 inches . Allowable total steering system free play is limited to 7 degrees. Stopping distance must be one and half distance of the vehicle length when driven at a
speed of 40 Kmph
IMPORTANT PARAMETERS FROM RULE BOOK
MACHINE AROUND THE MAN
CHASSIS DESIGN PROCESS
• Real time prototyping
• Material used-PVC pipes
• Dimensioning done in accordance with the tallest driver
• Parameters of the rule book considered
VEHICLE 3D VIEW
PRO-E was exercised to design the 3-D model of the roll cage
SPECIFICATION:-• Main hoop and front hoop
OD 40mmX2mm wall thickness• Side impact and bulkhead
OD 25.4mmX1.65mm wall thickness• Roll hoop bracing and driver restraint harness
OD 25mmX1.75mm wall thickness• Front bulkhead support
OD 25.4mmX1.25mm wall thicknessMaximum triangulation providedSide impact member attached at a height of 350mm.Maximum round corners for stress redistribution
Material specification:-• Material used- SAE 4130• Yield strength- 435 Mpa• Young’s Modulus- 205 Gpa• Ultimate strength- 670 Mpa• Poisson’s ratio- 0.29• Density- 7850 kg/m^3
CHASSIS / ROLL CAGE
CHASSIS ANSYS DIAGRAMS
fig1. Front impact
Fig2. Side impact
Front impact:-
• Force applied-12000N• Points constrained- all degrees of
freedom of rear most tubing were constrained
• FOS- 6.5
Side impact:-
• Force applied-12000N to side impact member
• Points constrained- SIM was constrained
• FOS- 5.1
CHASSIS ANSYS DIAGRAMS
fig4. Torsional stiffness
fig5. Static loading
Torsional stiffness:-
• Force applied-1000N at the end of test rod
• Deflection observed- 33mm• Torsional stiffness- 705.33 Nm/deg
Static loading:-
• Load due to driver’s weight- 686N• Engine and transmission- 2000N• Constraints- wishbone connecting
point• FOS- 16
CHASSIS DESIGN JUSTIFICATION
1. Main hoop:-
• Size- 65X92cm • height is kept low to minimize air drag• Bracing in compliance with the rule book
2. Front hoop:-
• Size- 40X50cm• Below the driver’s eye line• Bracing in compliance with the rule book
3.Front bulkhead:-
• Size- 32X30cm• Minimum frontal area• As per the suspension geometry
SUSPENSION GEOMETRY
1. Fully independent outboard suspension, unequal length, non-parallel, double A- arm design
2. Inference from the drawing:-• Trackwidth- 1200/1120mm• Wheel base- 1710mm• Ground clearance- 76.2mm• Roll centre- 5/9mm• Scrub radius- 16mm• KPI- 7/6 deg• Camber- -2/0 deg
3. Alternatives considered:-• Mc-Pherson strut• Swing axle suspension
1. Mc-pherson 2. Swing axle
SUSPENSION-SHOCK TYPES
Coil-over shocks:-• preferred over gas shocks due
its superior ability to respond after impact
• Has a high damping ratio
Correct valving and spring rate
Easily available and fits in constraining parameters.
STEERING SYSTEM
Type :- Rack and pinion
Alternatives considered:-• Pitman arm steering• Recirculating ball steering
Steering specification:-• custom made rack and pinion• material- mild steel• central steering for quicker response• steering angle- 280 to 40°• steering ratio- 5:1• lock-to- lock ratio- 1.25 turns• turning radius- 3m
BRAKING SYSTEM
Hydraulically operated braking system Disc brakes on all four wheels
Independent front and rear brake circuit Proportionating valve used to adjust the brake pressure difference between front and rear Maruti 800 master cylinder
Brake disc size-220m
Front circuit pressure=1.533 N/mm2
Rear circuit pressure=1.839 N/mm2
Stopping distance=2.85 m
Master cylinder size (diameter) Front =21.06 mm Rear =19.22mm
WHEEL ASSEMBLY
Tire specification:-185/60 R-13
Rim specification:-Alloy wheel rims13 X 6 ET-30
Hub:-custom made
Disc rotor:-220mm (OD)
Upright:-custom made
WHEEL HUB ANALYSIS
HUB DESIGN:-
• custom made hubs• material used:- SAE 4140• light weight to reduce unsprung mass and to ensure vehicle stability• provisions for brake disc mounting• two bearings in each hub for better stability
HUB ANALYSIS:-
• constraints- all DOF rim attachment positions were constrained• force applied- 10500N• FOS- 6.5-8
UPRIGHT ANALYSIS
Static nodal stress:-
• Force applied on upper and lower wishbone mounting point-450N each• Bearing hole constrained
Static displacement:-
• Force applied on upper and lower wishbone mounting point-450N each• Bearing hole constrained
Static nodal stress
Static displacement
ENGINE AND TRANSMISSION
Engine specification:-• Type- M800 BSIII MPI engine• Swept volume- 796cc• Maximum power- 26 Kw @ 5000rpm• Maximum torque- 59 Nm @ 2500rpm• Type of fuel used- gasoline• Compression ratio- 8.8
Transmission:-• Type- manual• Clutch type- dry, single plate• No. of gears- 4 forward, 1 reverse
GEAR GEAR RATIO OVERALL RATIO 1st 3.583 15.586 2nd 2.166 9.422
3rd 1.333 5.798 4th 0.900 3.915
reverse 3.363 14.629• Differential type- straight bevel gear• Final drive ratio- 4.350
TECHNICAL SPECIFICATION
GENERAL SPECIFICATION:-• Wheelbase-1710mm• Overall height-996.2mm• Track width-1200/1120mm• Ride height-76.2mm• Target weight-360kg• Maximum speed-110kmph DRIVE TRAIN SPECIFICATION:-
• Direct coupling• Transmission-4 FWD + 1 REV
CHASSIS SPECIFICATION• Material-SAE4130• Total weight-41kg
SUSPENSION SPECIFICATION:-• Type-LSA (front and rear)• Travel-2.2/2.5 inches• Camber- -2/0 deg• Castor- +4/+3 deg
STEERING SPECIFICATION:-• Lock-to-lock-1.25 turns• Steer angle-28-40 deg• Steering ratio-5:1
BRAKE SPECIFICATION:-• Type- 220mm disc brake (front and rear)• Dual tandem master cylinder
Today, necessity is more of a mother of INNOVATION than INVENTION
Concentrated towards building a SIMPLE, highly PERFORMANCE oriented, efficient and robust racing car fuelled to scorch the tracks.
PRINCIPLE CONCERNING MULTIFUNCTIONAL DEVICES: The fewer functions any machine is required to perform, the more perfectly it can perform those functions.
SIMPLE, SPEEDY, DURABLE, LIGHT WEIGHT AND ECONOMICAL VEHICLE.
INNOVATION
Various parts shall be checked by the following methods: CHASSIS: Real time prototyping will be done to test the key points
for strength. SUSPENSION: has been analyzed using SusProg3D and deflection
in shocks will be analyzed using spring test. BRAKING: Chassis Dynamometer. STEERING: Ground testing. ELECTRICAL: Ground testing.
Note:- All this will be done before running the actual drive cycle tests, by driving the vehicle around on MMST TRACK and at various speeds.
DESIGN VALIDATION PLAN
TARGET PERFORMANCE SHEET
• Maximum speed- 120kmph
• Acceleration- 3.2 m/s^2
• Stopping distance- 3m (@60kmph)
• Minimum turning radius- 3.5m
• Ground clearance- 3 inch
• Total vehicle weight- 350kg
Estimated cost of vehicle-Rs.3,50,000
Oil India Limited (sponsorship)- Rs. 50,000
College funds- Rs. 2,00,000
Personal contributions- Rs.75,000 (5,000 each)
Balance- Rs. 25,000**
**Remaining amount yet to managed.
MANAGING FUNDS ANDS SPONSORSHIP
The team is planning on using the college machine shop for various manufacturing needs.
COLLEGE FACILITIES
SERVICES AVAILED FROM OUTSIDE
• TIG- welding for chassis• CNC machining for hub and upright
TEAM DETAIL
S.No NAME BRANCH INCHARGE
1. Sandip Kumar Mechanical Team captain, Design engineer
2. Pradeep Kumar Maurya Mechanical Technical head, power transmission
3. Rubina Mahtab Khan Mechanical Spokesperson, chassis and suspension
4. Raj Kishore Mechanical Structural analysis, steering
5. Eshan Sett Mechanical Co-spokesperson, Chief presenter, Marketing
6. Prateek Singh Mechanical Fabrication head, Technician, Driver
7. Raju Das Mechanical Braking system
8. Sabir Fariz Hussain Mechanical Structural analysis, steering
9. Shriram Jhawar Mechanical Marketing and sponsorship
10. Gopi Uttakaran Mechanical Structural analysis and marketing
11. Shahnawaz Hussain Mechanical Cooling system
12. Ashish Abhishek ECE Software solutions, Electronics
13. Ashutosh Kumar ECE Electronics
14. Abhishek Singh CSE Software solutions, Co-driver
15. Dhiraj ETC Co-driver
Faculty advisor-X. CHARLES
SUPRA SAEINDIA 2011Main Rule Book Milliken & Milliken, Race Car Vehicle Dynamics, Warrendale, PA, SAE
Inc. Thomas D. Gillespie, Fundamentals of Vehicle Dynamics, Warrendale, PA,
SAE Inc. Carroll Smith, Tune to win, Fallbrook, CA, Aero Publishers Inc. http://www.fsae.com/ http://www.f1technical.net/ <http://www.howstuffworks.com
BIBLIOGRAPHY