Baja - Striders PPT

1. STRIDERZ
1
SAINTGITS COLLEGE OF ENGINEERING
KOTTAYAM, KERALA
A Step Forward

2. • The maximum dimensions: 64in x108in length.
• 6inch clearance from the driver’s helmet, 3inch clearance from other body parts with a straight edge
applied to any 2 points on the roll cage.
• The cockpit is designed to protect the driver under all conditions.
• 5sec escape from either side of the vehicle.
• A firewall between cockpit and the engine.
• The roll cage is designed in such a way that it does not compromise the vehicle’s integrity.
• Minimising of stopping distance during braking.
• Battery must be mounted with sound engineering practise and not come loose during a roll over.
• The exhaust pipe must be completely intact and operational throughout the competition.
• The complete exhaust system shall be located such that its extremities lie at least 100mm within the
perimeter of the vehicle.
2
10 SALIENT FEATURES

3. DESIGN TARGETS
PARAMETERS SPECIFICATIONS
Wheel base 58”
Track width 52”
Height of vehicle 63”
Height of CG 0.49837m
Ride height 20”
Lateral Pos. of CG from
rear
0.5416m
Turning radius 118”
Travel 10”
Max. Speed 55 Km/hr
Max Torque 530 Nm
3
3D MODEL

4. PROPOSED BAJA VEHICLE
4
FRONT VIEW
TOP VIEW
SIDE VIEW

5. CHASSIS
• Chassis design methodology – Ergonomics optimising design
5
Cockpit
Engine cage Suspension
mounting
Analysis
Condition Success
Proceed to
fabrication
Fail

6. 6
Torsion Test Roll Over Test
Front Impact Test

7. 7
Material
Yield strength
N/m2 Cost Factor Of Safety
AISI 1018 360000000 Rs.110/ft 15
C25 280000000 Rs.87/ft 17
AISI 1020
351571000 Rs.200/ft 36
MATERIAL SELECTION
• Carbon% : 0.20 - 0.30 %
• Mn % : 0.3 – 0.6 %
• Tensile strength : 440 – 540 N/mm
• Yield stress : 280 N/mm

8. 8
Parameters Front Rear
Roll center height 4.02’’ 5.21’’
Toe out/ Toe in 1 degree 1 degree
Caster 4 degree 0 degree
Motion ratio 0.37 0.41
Spring stiffness 35N/mm 72N/mm
• Chosen configuration : Double
A-arm (SLA)
• Ride height : 10”
• Maximum track width
(Front 54.4’’ Rear 54.6’’)
• Custom made upright and A arm
SUSPENSION

9. 9
Front Suspension Rear Suspension

10. 10
REAR
FRONT
Major equations:
• Wheel rate= Spring rate x IR^2cos(a)
• Spring stiffness= G(d)^3
nx64x(D)^4

11. 11
STEERING GEOMETRY

12. • Geometry : Trapezoidal
• Type : Ackermann Steering
• Steering Angle : 31.6°
• Tie Rod Length : 14 inch
• Steering Ratio : 12:1
• Turning Radius : 118 inch
• Steering Mechanism : Rack and Pinion
• Steering Effort :
output load at rack ∗ radius of pinion pitch circle
radius of steering wheel
= 34.11 N
12

13. BRAKES
Diagonal split hydraulic system
A pair of brake lines runs to each rear brake and the other runs to the front.
Actuation Subsystem
• Brake pedal
• Master cylinder
• Proportional valves
• Brake lines
Fbf = brake front force
Fbr = brake rear force
Wf = dynamic weight (front)
Wr = dynamic weight (rear)
h = height of CG from ground
CG = centre of gravity
Dynamic weight transfer
Wf = mgd + maxh
c+d c+d
Wr = mgd - mxh
c+d c+d
c d
13

14. F =
mv²
𝟐𝒔
• Hydraulically operated disc brake
• Master cylinder diameter = 20.64mm
• Caliper piston diameter = 50mm
• Front & Rear disc radius = 95mm
• Knee pressure = 10.25kgf
• Stopping distance = 12.3399m
• Pedal ratio = 3:1
• Pedal effort = 991.94N
14

15. TRANSMISSION
15
o 4 speed manual transmission
o Engine coupled inline with gearbox, hence lowering the CG
o Components: Mahindra Champion ALPHA trans axle, Maruti 800
wheel hub
ENGINE
COUPLER
GEARBOX

16. Gear 1 2 3 4
Total reduction 31.40 18.66 11.38 7.6134
o Overall powertrain efficiency: 0.85
o Tire diameter: 23 inches
o Maximum gearbox reduction: 31.6
o Maximum acceleration: 3.9 m/s^2
o Maximum engine torque : 19.6 Nm
o Maximum speed: 54.98 kmph
o Gradability – 43.83%
16

17. 17
ENGINE (30000)
TRANSMISSION (40000)
SUSPENSION (34000)
BRAKE AND STEERING (23000)
ACCESSORIES (25000)
CHASSIS(C25) (16000)
ELECTRICAL (10000)
COST ANALYSIS (Rs/-)
32%
21%
16%
6%
4% 21%
ROLLCAGE(94kg)
SUSPENSION AND STEERING (60kg)
POWERTRAIN(45kg)
ERGONOMICSANDSAFETY(18kg)
ELECTRICALANDINSTRUMENTS(11kg)
WHEELSANDBRAKE(62kg)
WEIGHT ANALYSIS (kg)
Total cost: Rs.1,78,000 Total weight: 290kg

18. 18

19. FN/ITEM NAME
POTENTIAL FAILURE
MODE
POTENTIAL
EFFECTS OF
FAILURE
S
E
V
POTENTIAL CAUSE(S) /
MECHANISM OF FAILURE
O
C
C
CURRENT DESIGN CONTROLS
PREVENTION
DETECTION
D
E
T
R
P
N
RECOMMENDED ACTION(S) ACTION(S) TAKEN
S
E
V
O
C
C
D
E
T
R
P
N
Chassis
Structural
(crack)
Will lead to
chassis failure
at high stress
area
6
Failure at high
concentration points ,
Inadequate maintenance
inspection,
Corrosion.
5
P : material with sufficient strength is
used
Proper design for effective stress
distribution
D : Identify weak members by analysis
4 120
Relatively high factor of safety
to ensure structural integrity
Use of cross members to lead
to better stress distribution
along the frame
Design optimized by
analysis
Improved chassis design
for better stress
distribution
5 4 4 80
Suspension
Crack on mountings
Buckling
Leakage
Complete
failure of
suspension
Baja vehicle
will not move
4
Overstressing
Inadequate motion ratio
Leaking of fluid inside the
damper
4
P : verification of desired specification
of component
Optimizing the component according
to the load conditions
D : Detection only by testing or analysis
3 48
Revised material specifications
Using the analysis result for
proper positioning of the
mounting points
The specification of the
component is optimized
The mounting point is
designed effectively
4 4 3 48
Steering Fracture
Deformation
Rough
operation
Poor steering
5
Overstressing
UV Joint failure
Wear of gear teeth
4
P : proper analysis of different
components
D : Loss of control
Unusual noise
Increase in steering effort
2 40
Verify the material
specifications
Analysis is done for the tie rods
and their mountings for
improved design
Material is selected
appropriately
Gear design is done
effectively
5 4 2 40
Brake Crack
Leakage
Inoperative 6
Due to the stress produced
from impact
Piston Wear
Improper joints and routing
of brake lines
4
P : efficient routing of brake lines
Use high quality materials for the lining
D : Inefficient braking
More travel to the brake pedal
Leaks in the vehicle
5 120
Using components with
specified standards
The routing of brake lines are
optimized
The position of
components is optimized
and ensured that the
quality is at its best
5 3 5 75
Transmission
Breakdown of rear
axle.
Engine – gearbox
coupling failure
Vehicle
breakdown.
6
Rough track conditions.
High end Engine – gearbox
vibrations
4
P: Proper design to avoid high stress on
trans axle.
D: unusual stopping of vehicle
4 96
Using couplings which can cop
up with the off road conditions.
Reducing the overall engine –
gearbox vibrations.
Optimised couplings and
single member mounting
designs are validated.
Usage of rubber bush to
reduce vibration.
4 3 4 48
19

20. COLLEGE FACILITIES
20
SL.NO VEHICLE PART MANUFACTURING PROCESS FACILITIES AVAILABLE SPECS
TESTING
EQUIPMENTS
AVAILABLE
1 CHASSIS
PIPE CUTTING
WELDING
PIPE BENDING
GRINDING
ROTARY PIPE CUTTER
DC&AC ARC
POWER SAW
HAND GRINDER
BENCH GRINDER
SIGMA UTC-280T
SWING DIA 560mm
UTM
2 SUSPENSION
WELDING
DRILLING
PLAINING
SHAPING
DC&AC ARC WELDING
DRILLING MACHINE
PLANER
SHAPER
1 HP,1425RPM
SPRING TESTING
MACHINE
3 TRANSMISSION
SLOTTING
MILLING
DRILLING
TURNING
SLOTTING MACHINE
MILLING MACHINE
DRILLING MACHINE
ENGINE LATHE
CNC LATHE
PREMAC PMS-200
1.5HP
1 HP,1425RPM
FATIGUE TESTING
MACHINE

21. STRIDERZ
Board of directors
Captain
Vice captain
Treasurer
Suspension &
steering
Chassis Transmission
Braking &
Electrical
Marketing &
Logistics
Faculty Advisor
Roll cage
Material
Body panel
Wishbone
Coil over spring
Rim & Tire
Rack & Pinion
Tie rod
Hub & upright
Engine
Drive layout
CVT
Gear box
Transaxle
Disc & caliper
Pedal
Kill switch
Circuit
Interviews
Project plan
Inventory
Cost analysis
21

22. THANK YOU
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