2. GENERAL SPEC.S SELECTED
Body Type Space
frame(AISI 1018
STEEL )
Kerb Weight 270 Kg
Overall Dimensions 98”*65”*60”
Wheel Base 65”
Track Width Front-52”
Rear-48”
Ground Clearance 13”
SUSPENSION TYPE
Front Type Travel Unparallel Unequal
Double Whisbone
Rear Type
Travel
Unparallel Unequal
Double Whisbone
Shocker Type
Spring Deflection
Hydraulic Spring
Damper
BRAKES SELECTED
Type Hydraulic Disc
Brake(Pulsar)
Rotor Size
(Front/Rear)
220 mm /
200 mm
Cylinder Dual Master
Cylinder
Stooping
Distance(m)
12
ENGINE &
TRANSMISSION VALUES
Type
Manual
Gear box Mahindra Alfa 4
Acceleration m/s2 0.773
Maximum Speed
(Kph)
53 kmps
0-53 kmph 21 s
TECHNICAL SPECIFICATION AND PERFORMANCE OF PROPOSED VEHICLE
STEERING VALUES
Design Rack & Pinion
Centralized(11”)
Geometry Over True Ackerman
Turning Radius(m) 2.57
Steering Ratio 12:1
3. Roll cage Ergonomics Member Roll Cage
Member
s
Dimensi
on
Primary
Member
RRH
RHO
FBM
LC
FLC
LFS
1”OD
:
0.120”(3m
m)
thickness
Secondary
Member
LBD
SIM
FAB
USM
ALL CROSS
MEMBERS
1”OD
:
0.039”(1m
m)
thickness
Roll Cage Material
Physical Property
AISI 1018 Mild
Steel
Density 7.7 gm/cc
Yield strength 383 MPa
Ultimate Tensile
Strength
440 MPa
cost Rs-140/- /ft
Poisson’s Ratio 0.29
Young’s Modulus 205 GPa
Carbon Content 0.18%
Driver’s helmet should have 6” (152mm)clearance to
the side of surface(RHO).Roll Cage must provide a
clearance of 3” to driver.
Spacious enough to accommodate a person with 95th
percentile male to the 5th percentile female population.
Reduction in weight due to selection of material with
high strength to weight ratio
Smaller thickness is selected for secondary members
resulting reduction in weight.
Front end of then RHO members of must be at least 12”
forward vertically from the side bottom.
Angle between the FBM and the vertical members is <45
degree.
SIM is at 8-14” above the seat bottom.
Material Tubing SAE 1018 Mild
Steel
Outside Diameter 25.4 mm
Inside Diameter 19.4mm
Wall Thickness 3mm
4. Roll Cage Analysis
Particulars Front
Impact
Rear
Impact
Side
Impact
Roll
over
Torsoinal
Rigidity
Front wheel
bump test
Total applied
force (N)
8G 8G 4G 2G 2G 1G
Maximum total
deformation
(mm)
1 12 5.25 1.4 1.4 0.7
Max. Combined
stress (MPa)
214 290 325 178 106 250
FOS 3.09 1.5 1.33 2.4 4.14 2.8
Stiffness of Roll
cage (N/mm)
4421 2040 736 896 3139 784.2
Roll over Deformation
Rear Impact Deformation
Side Impact Deformation
Front Impact Deformation
Torsional Rigidity
Deformation
Bumping
Deformation
Particulars Constraints Forces applied
Torsional One side of front
suspension
Another side of front
suspension
Drop Suspension
mounting points
At LFS node points
Bump Suspension
mounting point
Shocker mounting point
5. SUSPENSION DESIGN –FRONT / REAR
Static Data's
Camber angle -2.3 deg
Caster angle +3.2 deg
King pin angle 6 deg
Roll centre height 5” from
ground
Scrub radius (mm) 45.27
Particulars Front Rear
Spring stiffness (N/mm) 23 18
Spring travel (inch) 5 4
Natural frequency (Hz) 0.78 0.9
Motion ratio 0.79 0.91
Results
Roll centre height
• Front 241 mm
• Rear 341mm
Centre of gravity
height = 18 inch
Ground Clearance =13
13”
Design Considerations
Kingpin and caster angle are kept in such a way that they can compensate each others camber gain, by
providing there individual function.
A positive king pin angle is kept to help in steering the vehicle.
Roll centre below CG to avoid jacking force.
Front ride frequency is greater than rear.
Roll axis inclined towards front to give understeer characteristic.
Front double wishbone unequal parallel arm to have better traction during cornering.
*Static camber : -2.3
•Caster:- +3.2˚
*Spring Constant
( Front):- 23 N/mm
*Spring constant
(Rear) :- 18 N/mm
* 1° of toe change per 6’’
of travel
* Static Roll Center
Height – 5 ‘’ from ground
* Wheel Travel
7’’ – Up , 5’’ - Down
Camber change during bump Caster change during bump
Change in Roll Center Height
Graphs of Bump and Roll analysis
Front lower A arm Deformation
% change in ant-dive with bump Damper Travel During Bump
Toe change during bump
Upright analysis result
Front lower A arm Deformation
Anti Dive Geometry in LOTUS Suspension Analysis
suspension
Spring material Oil Temperd
low carbon
steel
Spring wire Dia 10 mm
Sprung mass 250 Kg
Unsprung Mass 100 Kg
6. THERMALANALYSIS OF DISC
Brake Geometry Specification
Brake Type 4 Wheel Disc Brake
Split Type Front & Rear
Disc Size Front (mm) Bajaj 220
Disc Size Rear (mm) Bajaj 200
Master Cylinder area(mm2) 285.02
Breaking Torque( Front/Rear) 1047 Nm
952 Nm
Design Parameter Values
Static load at front axle (kg) 128.24
Static load at rear axle (kg) 222.75
Total weight of the vehicle (Target)
(kg)
350
Dynamic load @ front axle (Braking)
(N)
1786
Dynamic load @ rear ( Braking ) (N)
Height of C.G form ground (inch) 18
Distance of C.G from rear axle (inch) 40.55
Distance of C.G from front axle
(inch)
23.44
Rolling radius (inch) 12
Coefficient of friction between road
and wheels
0.7
In order to achieve “Optimum Brake
Balance”, or to
achieve 100% base brake efficiency, the
ratio of the front
and rear dynamic braking forces will be
equal to the ratio of
the front and rear vertical forces (axle
weights).
Under-steering & Over-steering, both
possible with brake bias adjustment.
Bias bar takes force from one side and gives
to another.
60% of braking capacity should be on front
tires due to dynamic weight transfer.
Keeping the 60-40 %, the stopping distance
of the ATV will reduce.
While braking the Anti-Dive Geometry
reduces the effect of weight transfer.
Calculations done to achieve “Optimum
Brake Balance”
128.24 Kg 222.57Kg
C.G
11.89m Stopping Distance
F R
40.56”
18”
85 kg Load trtransfer
7. Centralized Rack and Pinion.
Over True Ackerman Geometry.
• Design Considerations:
Cot(Ø)-Cot(Ɵ)=(Distance b/w
kingpins)/Wheelbase,
Sin(ɑ+Ɵ)+Sin(ɑ-Ø)=2Sin(ɑ),
Rof = (b/sin(Ø))+(a-c)/2,
• Specification of rack and pinion:
Rack Length(eye to eye) = 11
inches,
Rack Travel(centre to lock) = 2.25
inches,
Pinion Rotation(centre to lock)=2700
Over True Ackerman Geometry in CATIA
Proposed design in CATIA
Variables values
Type Centrally aligned rack &
pinion
Steering rake (inch) 11
Steering Ratio 12:1
No. of turns(cent to lock) 1.3
Turning radius(m) 2.57
Turning angle(Inner) deg. 40
Turning angle(Outer)
deg.
27.56
Ackerman angle deg 28.3
steering wheel
diameter(mm)
185
Tie rod ( inch) 16.5
11” Rack And Pinion
8. POWER TRAIN
ENGINE SPECIFICATIONS
MAX POWER 10 HP
MAX TORQUE 19 N-m
PERFORMANCE
ACCELERATION
TEST
Acceleration :
0.773 m/s2
0 – 60
kmph
in
21.58
s.
HILL
CLIMBING
TEST
Speed :
13.162 kmph
At a
Grada
bility
of
100%
.
GEAR RATIO
GEAR GEAR RATIO SPEED
1ST 31.48:1 12 kmph
2nd 18.70:1 21.04 kmph
3rd 11.40:1 34.53 kmph
4th 7.35:1 53 kmph
BASIC CALCULATION
PARAMETER TYPE / VALUE
GEAR BOX MAHINDRA ALPHA
TRANSMISSION
ORIENTATION
FORWARD/ REAR
ENGINE REAR WHEEL
COUPLING TYPE MANUAL/ DIRECT
COUPLING
TRACTIVE FORCE 427.21N
MAXIMUM SPEED 53 kmph
TIME 0-53 KMPH IN 19.07
seconds.
TYRE
SPECIFICATION
VALUES
Wheel Size(Front
& Rear)
24”*8”*12”
Rim Outer
Diameter
12”
Width 8”
Analysis of stress induced in muff coupler
9. Roll Cage
6% Engine &
Transmissio
n
27%
Suspension
& Wheel
40%
Brakes
5%
Steering
6%
Safety(Hel
met,Driver
Suit,Fire
Extinguishe
r)
12%
Others
4%
Roll Cage
20%
Transmissi
on
21%
Suspensio
n
12%
Wheel &
Rim
16%
Brakes
7%
Steering
3%
Safety
8%
Others
13%
Chart Title
COST AND WEIGHT ANALYSIS PIE CHART
COST- 272650/-
WEIGHT-270 Kg
10. Sl no. Task name Duration Start Finish
INITIATION STAGE
1. Team selection & allotment of departments 15 days MARCH 5, 2015 MARCH 20, 2015
2. Conceptualization & market availability 10 days MARCH 21, 2015 MARCH 30,2015
3. Sponsorship procurement plan 20 days APRIL 1, 2015 APRIL 15, 2015
4. Team registration 2 days APRIL 16, 2015 APRIL 17, 2015
DESIGN AND ANALYSIS STAGE
5. Design selection & calculations 20 days APRIL 24,2015 MAY 14, 2015
6. Part design & Analysis using various softwares 20 days MAY 20, 2015 JUNE 10, 2015
7. Assembling & rendering 3D view 5 days JUNE 11, 2015 JUNE 15, 2015
8. Preparation of presentation 10 days JUNE 21, 2015 JULY 1, 2015
BAJA SAEINDIA 2016 VIRTUALS, CHITKARA UNIVERSITY, CHANDIGARH 2 days JULY 10, 2015 JULY 11,2015
MATERIAL PROCUREMENT STAGE
9. Stage 1:1018 steel tubes, welding equipments, suspension, power trains, brakes, steering components 20 days JULY 20, 2015 AUGUST 8, 2015
10. Stage 2:Safety and electrical equipments, other miscellaneous items. 15 days AUGUST 13, 2015 AUGUST 27, 2015
MANUFACTURING STAGE
11. FABRICATION STAGE: Roll cage built up, Hub, upright, suspension arms, gearbox etc 32 days SEPTEMBER 1, 2015 OCTOBER 2, 2015
12. ASSEMBLY STAGE: Engine, power train installation, Suspension, Brake, steering system 20 days OCTOBER 3, 2015 OCTOBER 22, 2015
13. COMPLEMENTATION STAGE: Safety, electrical system installation, Aesthetics (body panelling, padding, painting) 15 days OCTOBER 24, 2015 NOVEMBER 8, 2015
DESIGN VALIDATION & REFINEMENT
14. STATIC TESTING PHASE
Weld test & Drop test, Go-on-go Test, fuel leak test, eggression test
Straight line stability, lock to lock angle, percentage ackermann & turning radius
Top speed test, acceleration test & brake test, Figure of 8 test
8 days NOVEMBER 9, 2015 NOVEMBER 16, 2015
15. DYNAMIC TESTING PHASE
•Gradability test Suspension test Manuverability test
10 days NOVEMBER 18, 2015 NOVEMBER 27, 2015
16. ENDURANCE TEST 31 days NOVEMBER 29, 2015 DECEMBER 29, 2015
DOCUMENTATION (SCCS, COST & DESIGN)
16. TECHNICAL INSPECTION
•Vehicle launching & promotional activities
8 days JANUARY 1, 2015 JANUARY 8, 2015
BAJA SAE MAIN EVENT-2016, INDORE : 4 days
PROJECT PLAN & VALIDATION REPORT