This project report summarizes work done by a student team to apply homework calculations to measurements taken from a 2004 Mitsubishi Galant.
The team measured vehicle specifications, completed three homework problems involving calculations of engine speed, torque, fuel consumption, effective mass, acceleration, and brake performance.
Calculations were shown for static and dynamic load conditions, effects of passengers and a trailer, and comparisons of wheel loads with and without a load-equalizing hitch. Braking forces and times to accelerate to 300 mph in a quarter mile were also estimated.
ME010 801 Design of Transmission Elements
(Common with AU010 801)
Teaching scheme Credits: 4
2 hours lecture, 2 hour tutorial and 1 hour drawing per week
Objectives
To provide basic design skill with regard to various transmission elements like clutches, brakes, bearings and
gears.
Module I (20 Hrs)
Clutches - friction clutches- design considerations-multiple disc clutches-cone clutch- centrifugal clutch -
Brakes- Block brake- band brake- band and block brake-internal expanding shoe brake.
Module II (17 Hrs)
Design of bearings - Types - Selection of a bearing type - bearing life - Rolling contact bearings - static
and dynamic load capacity - axial and radial loads - selection of bearings - dynamic equivalent load -
lubrication and lubricants - viscosity - Journal bearings - hydrodynamic theory - design considerations -
heat balance - bearing characteristic number - hydrostatic bearings.
Module III (19 Hrs)
Gears- classification- Gear nomenclature - Tooth profiles - Materials of gears - design of spur, helical,
bevel gears and worm & worm wheel - Law of gearing - virtual or formative number of teeth- gear tooth
failures- Beam strength - Lewis equation- Buckingham’s equation for dynamic load- wear loadendurance strength of tooth- surface durability- heat dissipation - lubrication of gears - Merits and
demerits of each type of gears.
Module IV (16 Hrs)
Design of Internal Combustion Engine parts- Piston, Cylinder, Connecting rod, Flywheel
Design recommendations for Forgings- castings and welded products- rolled sections- turned parts,
screw machined products- Parts produced on milling machines. Design for manufacturing - preparation
of working drawings - working drawings for manufacture of parts with complete specifications including
manufacturing details.
Note: Any one of the following data book is permitted for reference in the final University examination:
1. Machine Design Data hand book by K. Lingaiah, Suma Publishers, Bangalore/ Tata Mc Graw Hill
2. PSG Design Data, DPV Printers, Coimbatore.
Text Books
1. C.S,Sarma, Kamlesh Purohit, Design of Machine Elements Prentice Hall of India Ltd NewDelhi
2. V.B.Bhandari, Design of Machine Elements McGraw Hill Book Company
3. M. F. Spotts, T. E. Shoup, Design of Machine Elements, Pearson Education.
Reference Books
1. J. E. Shigley, Mechanical Engineering Design, McGraw Hill Book Company.
2. Juvinall R.C & Marshek K.M., Fundamentals of Machine Component Design, John Wiley
3. Doughtie V.L., & Vallance A.V., Design of Machine Elements, McGraw Hill Book Company.
4. Siegel, Maleev & Hartman, Mechanical Design of Machines, International Book Company
this project is design of bevel gear box
A Gearbox is a device that used for transmitting power from the Power source to
the output shaft. A gearbox has a set of gears that are enclosed in a casing. The gears are
mounted on shafts which rotate freely about their axis
This document is about power transmission system. It's aimed those interested in learning about mechanical engineering and students who are studying various programmes in engineering. This document only deals with power transmission through flat and v-belts.
ME010 801 Design of Transmission Elements
(Common with AU010 801)
Teaching scheme Credits: 4
2 hours lecture, 2 hour tutorial and 1 hour drawing per week
Objectives
To provide basic design skill with regard to various transmission elements like clutches, brakes, bearings and
gears.
Module I (20 Hrs)
Clutches - friction clutches- design considerations-multiple disc clutches-cone clutch- centrifugal clutch -
Brakes- Block brake- band brake- band and block brake-internal expanding shoe brake.
Module II (17 Hrs)
Design of bearings - Types - Selection of a bearing type - bearing life - Rolling contact bearings - static
and dynamic load capacity - axial and radial loads - selection of bearings - dynamic equivalent load -
lubrication and lubricants - viscosity - Journal bearings - hydrodynamic theory - design considerations -
heat balance - bearing characteristic number - hydrostatic bearings.
Module III (19 Hrs)
Gears- classification- Gear nomenclature - Tooth profiles - Materials of gears - design of spur, helical,
bevel gears and worm & worm wheel - Law of gearing - virtual or formative number of teeth- gear tooth
failures- Beam strength - Lewis equation- Buckingham’s equation for dynamic load- wear loadendurance strength of tooth- surface durability- heat dissipation - lubrication of gears - Merits and
demerits of each type of gears.
Module IV (16 Hrs)
Design of Internal Combustion Engine parts- Piston, Cylinder, Connecting rod, Flywheel
Design recommendations for Forgings- castings and welded products- rolled sections- turned parts,
screw machined products- Parts produced on milling machines. Design for manufacturing - preparation
of working drawings - working drawings for manufacture of parts with complete specifications including
manufacturing details.
Note: Any one of the following data book is permitted for reference in the final University examination:
1. Machine Design Data hand book by K. Lingaiah, Suma Publishers, Bangalore/ Tata Mc Graw Hill
2. PSG Design Data, DPV Printers, Coimbatore.
Text Books
1. C.S,Sarma, Kamlesh Purohit, Design of Machine Elements Prentice Hall of India Ltd NewDelhi
2. V.B.Bhandari, Design of Machine Elements McGraw Hill Book Company
3. M. F. Spotts, T. E. Shoup, Design of Machine Elements, Pearson Education.
Reference Books
1. J. E. Shigley, Mechanical Engineering Design, McGraw Hill Book Company.
2. Juvinall R.C & Marshek K.M., Fundamentals of Machine Component Design, John Wiley
3. Doughtie V.L., & Vallance A.V., Design of Machine Elements, McGraw Hill Book Company.
4. Siegel, Maleev & Hartman, Mechanical Design of Machines, International Book Company
this project is design of bevel gear box
A Gearbox is a device that used for transmitting power from the Power source to
the output shaft. A gearbox has a set of gears that are enclosed in a casing. The gears are
mounted on shafts which rotate freely about their axis
This document is about power transmission system. It's aimed those interested in learning about mechanical engineering and students who are studying various programmes in engineering. This document only deals with power transmission through flat and v-belts.
Automobile differential unit explained with the types and general maintenance. Procedure involved in dis-assembly of differential unit is also explained. Then solutions for common problem in differential unit.
Design of toggle jack.
This ppt includes design of basic components of jack like screw, Nut, Links etc.
Graphics will be clear all concept about design
Automobile differential unit explained with the types and general maintenance. Procedure involved in dis-assembly of differential unit is also explained. Then solutions for common problem in differential unit.
Design of toggle jack.
This ppt includes design of basic components of jack like screw, Nut, Links etc.
Graphics will be clear all concept about design
It is obvious that vehicle weight has a linear relationship
with the energy to be dissipated (stored) and the change
in velocity required has a exponential relationship.
• Deceleration times and stopping distances vary
somewhat for all vehicles on a given road surface.
• It should then be obvious that sizing the brake system
components has critical importance with respect to the
potential vehicle velocity and the mass of the vehicle.
• Note that heavy trucks generally have greater stopping
distances as compared to typical passenger cars.
Automotive data integration: An example of a successful project structureETLSolutions
In this presentation we show our system for integrating Automotive dealer data, using examples of two projects for a major manufacturer. The presentation includes sample reports and the process used.
Ceramic bearings are typically constructed with a ferrous inner and outer ring or race with ceramic balls in the place of steel. Ceramic bearings offer many advantages over all steel bearings, such as higher speed and acceleration capability, increased stiffness, lower friction and more. Ceramic balls are also nonconductive. Ceramic bearings are available in all standard industry configurations such as, angular bearings, thrust bearing, pillow block bearing, needle bearings, and roller bearings.
Vertical Screw Conveyor Design Project for MEX5277 - Machine Design
Step by step guide on how to create a Vertical Screw Conveyor.
Power calculation of a vertical screw conveyor.
Design calculation & different analysis of hybrid vehicle Avinash Barve
The hybrid car is one which uses Two or more energy.
The electric power engine works at lower speed and gasoline engine at higher speed
The hybrid engine automatically off while car is stopped and restart while you accelerate
hello folks;
In this documentation, A 2 stage bevel reduction gearbox is designed.
The example taken is of the gearbox requirement for the Box-shipping conveyor. All the necessary design calculations for gears and shafts are carried out in a proper and easy-to-understand sequence. The material selection, standardized components (keys, oil seals likewise)selection from the design databook is also discussed with reasoning. As and when needed concepts are explained with the help of suitable graphs, visuals, and drawings.
This report is authorized by the team member's name mentioned on Slide.
Thank you!!
If you find it helpful do like&l share it with your engineering friends
1. AME 451
Project Report
Submission Date: August 13,2014
Instructor: Mukherjee, Jyoti
Team members: Molani, Mohammad Salem
Jun, Youra
Cao, Zhe
2. Table of Contents
Table of Contents ...............................................................................................................................2
Introduction .......................................................................................................................................2
Results and calculations ......................................................................................................................2
Part 1. Vehicle information and measurements..................................................................................2
Part 2. Homework Problems ............................................................................................................4
HW 1A.......................................................................................................................................4
HW 2..........................................................................................................................................7
HW3 ........................................................................................................................................10
Conclusion.......................................................................................................................................19
Introduction
How would it be if the students get to work and apply the homework problems calculations into
a real car? This project is one of the best opportunities for the group members in order to face the
real engineering duty. The group started from identifying the vehicle information and gets to
know about the vehicle features and how things work. After manually measuring the data needed
from the car to solve the homework problems, the group came up with reasonable results beside
that, there are numbers assumed by the group members for solving the problems.
Results and calculations
Part 1. Vehicle information and measurements
Vehicle Used : 2004 Mitsubishi Galant 3.8 liter GTS
Engine ID: 6G75
Vehicle ID (VIN): 4A3AB76S74E106239
Tire ID: DOT 93 ENB0621311
Wheelbase (L): 108.5”
Tread Width: 8.5”
Static Loaded Radius(R): 13”
3. When Car is empty;
Gross Vehicle Weight : 4541 lbs
Static Front Wheel Load(Rf) : 2491 lbs
Static Rare Wheel Load(Rr) : 2050 lbs
Distance from the ground to the bottom of the vehicle (hi) : 8.75”
Vertical location of the center of gravity (ycg) : 24” from the ground
Horizontal location of the center of gravity (xcg) : 49” from the front wheel
o Calculating the horizontal location of the center of gravity
∑ 𝑇𝑓 = 4541𝑙𝑏𝑠 ∙ 𝑥 𝑐𝑔 − 2050𝑙𝑏𝑠 ∙ 108.3𝑖𝑛 = 0
x =
2050𝑙𝑏𝑠 ∙ 108.3𝑖𝑛
4541𝑙𝑏𝑠
= 49𝑖𝑛
When there are two passengers;
Weight of two passengers (Wp) : 398.7 lbs
Distance from the ground to the bottom of the vehicle (hf) : 7.5”
Vertical location of the center of gravity of the passengers (yp) : 29” from the ground
Horizontal location of the center of gravity of the passengers(xp) : 19” from the front
wheel.
4. Spring rate (k):
o Calculating the spring rates
k =
W
2δ
=
W 𝑝
2(ℎ 𝑖−ℎ 𝑓)
=
W 𝑝
2(ℎ 𝑖−ℎ 𝑓)
=
398 .7lbs
2(8.75in−7.5𝑖𝑛)
= 159.48 𝑙𝑏𝑠/𝑖𝑛
Brake Gain of the front wheel (Gf) : 0.22
N∙m
kPa
per wheel
Brake Gain of the rear wheel (Gr) : 0.15
N∙m
kPa
per wheel
Part 2. Homework Problems
HW 1A
Usingthe data foundinpart 1, answerthe followingquestions.
a) Find the longitudinal position of the combined CG.
x =
∑(𝑤𝑒𝑖𝑔ℎ𝑡 ∙ 𝑋)
∑ 𝑤𝑒𝑖𝑔ℎ𝑡
=
4541𝑙𝑏𝑠(49")+ 398.7𝑙𝑏𝑠(89.5")
4541𝑙𝑏𝑠 + 398.7𝑙𝑏𝑠
= 52.3"
5. b) Determine the axle loads of the loaded vehicle.
Balancing the moment about front axle.
R 𝑟 ∙ 108.5" = (4541lbs + 398.7lbs)(52.3")
R 𝑟 = 2381.07𝑙𝑏𝑠
Balancing vertical direction forces
𝑅 𝑟 + 𝑅𝑓 = 4541𝑙𝑏𝑠 + 398.7𝑙𝑏
R 𝑓 = 2558.63𝑙𝑏𝑠
c) Find the vertical position of the combined CG.
y =
∑(𝑤𝑒𝑖𝑔ℎ𝑡 ∙ 𝑦)
∑ 𝑤𝑒𝑖𝑔ℎ𝑡
=
4541𝑙𝑏𝑠(24") + 398.7𝑙𝑏𝑠(29")
4541𝑙𝑏𝑠 + 398.7𝑙𝑏𝑠
= 24.4"
d) What are the axle loads when it accelerates at 3m/sec2?
Forward acting force
F = ma = (
4541𝑙𝑏𝑠
32.2𝑓𝑡
𝑠𝑒𝑐2
)(
3𝑚
𝑠𝑒𝑐2
)(
3.28𝑓𝑡
1𝑚
) = 1387.68 𝑙𝑏𝑠
Balancing moments about the front axle
(1387.68lbs)(24.4")+Rr(108.5")=(4541lbs+398.7lbs)(52.3")
𝑅 𝑟 = 2069𝑙𝑏𝑠
6. Balancing moments about the rear axle
(1387.68lbs)(24.4")-Rf(108.5")=(4541lbs+398.7lbs)(108.5"-52.3")
𝑅 𝑟 = 2870.69𝑙𝑏𝑠
e) What are the axle loads when the trailer shown in the figure is connected up? The trailer
hitch on the car is 90mm behind the rear axle.
Balancing moments about hitch
610kg(9.81m/𝑠2)(2.8m) = 𝑅𝑡(3.25𝑚)
𝑅𝑡 = 5155.5𝑁 = 1159.0 𝑙𝑏𝑠
Balancing the force in order to find the force at hitch
𝑅ℎ = 610kg(9.81m/s2
)− 5155.5N = 828.6N = 186.28lbs
Taking the car and balancing moment about front axle
𝑅 𝑟(108.5")=(4541lbs+398.7lbs)(52.3") + 186.28𝑙𝑏𝑠((0.98𝑚)(
39.37"
1m
) + 108.5")
𝑅 𝑟 = 2633.59lbs
Balancing vertical direction forces
𝑅 𝑟 + 𝑅𝑓 = 4541𝑙𝑏𝑠 + 398.7𝑙𝑏 + 186.28𝑙𝑏𝑠
R 𝑓 = 2492.39𝑙𝑏𝑠
7. f) Because of the high rear axle load on the car, the owner installs a “load-equalizing” hitch.
This hitch puts a torque of 1500Nm (=13276.1lbs*in) into the connection point as
illustrated in the figure below. What are the wheel loads (car and trailer) with the load
equalizer?
Balancing the moment about the hitch.
610kg(9.81m/𝑠2)(2.8m) + 1500N ∙ m = 𝑅𝑡(3.25𝑚)
𝑅𝑡 = 5617𝑁 = 1262.75𝑙𝑏𝑠
load at hitch = Rℎ = 610𝑘𝑔(9.81𝑚/𝑠2 )− 5617𝑁 = 367.1N = 82.53𝑙𝑏𝑠
Taking the car and balancing moment about front axle
𝑅 𝑟(108.5") + 13276.1𝑙𝑏𝑠 ∙ 𝑖𝑛
= (4541𝑙𝑏𝑠 + 398.7𝑙𝑏𝑠)(52.3") + 82.53𝑙𝑏𝑠(108.5" + 38.57")
𝑅 𝑟 = 2370.58𝑙𝑏𝑠
HW 2
There are 3 problems in the HW 2. We are going to use all data we measured.
Q1. If the vehicle is running at 80km/hr up a 2% grade. The drag from aerodynamics and
rolling resistance is 572N. It is operating in third gear, which has a ratio of 1.2, and has a
final drive ratio of 3.5.With the given data and the measurements in part 1, answer the
following questions.
8. (a) What is the engine speed (RPM)?
Angular velocity =
𝑣
2∗𝜋∗𝑟
=
80
𝑘𝑚
ℎ𝑟
∗10.936
𝑖𝑛
𝑠
2 ∗𝜋∗13 in
= 422.86
𝑟𝑎𝑑
𝑠
𝑛1
𝑛2
=
𝑡1
𝑡2
,
𝑤2
𝑤1
=
𝑡1
𝑡2
422.86
𝑤1
= 1.21, 𝑤1 = 349.47 𝑟𝑎𝑑/𝑠
(b) How much torque (N-m) does the engine develop to maintain a constant speed if the
driveline efficiency is 91%.
4541 lb = 2059.88 kg = 20207.45 N; 13 in = 0.33 m
Ft = 572 N + 0.02 * 20207.45 N = 976.15 N
Tt = Ft * r = 976.15 N * 0.33 m = 322.13 Nm
T2 =
𝑇𝑡
𝑁𝑟∗𝑁𝑓∗ 𝜂
=
322 .13 𝑁𝑚
1.21∗3.5∗0.91
= 83.59 𝑁𝑚
(c) If the engine has a brake-specific fuel consumption of 0.3 kg/kw-h at these conditions,
what is the fuel consumption (kg/km)? Also give it in liters/100 km, assuming gasoline
weighs 0.78 kg/liter.
Power developed by the engine = T2 * w1 = 83.59 Nm * 349.47 rad/s = 29.21 KW
Fuel consumption = 29.21 KW * 0.3
𝑘𝑔/ℎ𝑟
𝑘𝑤
= 8.76
𝑘𝑔
ℎ𝑟
=
8.76 𝑘𝑔/ℎ𝑟
80 𝑘𝑚/ℎ𝑟
= 0.11
𝑘𝑔
𝑘𝑚
= 0.11
𝑘𝑔
𝑘𝑚
∗
1 𝑙𝑖𝑡𝑒𝑟
0.78 𝑘𝑔
= 0.14
𝑙𝑖𝑡𝑒𝑟
𝑘𝑚
= 14
𝑙𝑖𝑡𝑒𝑟𝑠
100 𝑘𝑚
Q2. The engine of a vehicle has a moment of inertia of 0.277 kg-m2. It is operating in first
gear (ratio of 7.53), has a final drive ratio of 4.11, and the tire radius is 0.508m.
(a) What is its effective mass of the engine?
𝑀 𝑒𝑓𝑓 =
𝐼∗ 𝑁2
𝑟2 =
0.277 𝑘𝑔−𝑚2
∗ (7.53∗4.11)2
(0.33 𝑚)2 = 2436.27𝑘𝑔
(b) What is the “mass factor” for this condition?
Mass Factor =
𝑀+ 𝑀 𝑒𝑓𝑓
𝑀
=
2059 .88 𝑘𝑔+2436 .27 𝑘𝑔
2059.88 𝑘𝑔
= 2.18
9. Q3. The vehicle can accelerate to 300mph in a quarter mile. The performance can be
modeled rather simply by assuming that the engine delivers constant power during
acceleration, and neglecting rolling resistance and aerodynamic drag forces.
(a) Derive and solve the differential equation relating velocity to distance for this case.
𝐹𝑥 = 𝑀 ∗ 𝑎 𝑥 = 𝑀 ∗
𝑑𝑉
𝑑𝑡
P = 𝐹𝑥 ∗ 𝑉; 𝐹𝑥 =
𝑃
𝑉
; 𝑎𝑛𝑑 𝑉 =
𝑑𝑥
𝑑𝑡
𝑃
𝑉
∗ 𝑑𝑡 =
𝑃
𝑉
∗
𝑑𝑥
𝑉
= 𝑀 ∗ 𝑑𝑉
∫ 𝑑𝑥
𝑥
0
=
𝑀
𝑃
∗ ∫ 𝑉2
∗ 𝑑𝑉
𝑉
0
X =
𝑀
𝑃
∗
𝑉3
3
(b) If the dragster weighs 4541 lb, how much power is develop to achieve acceleration to 300
mph in the quarter mile? (Neglect driveline inertia)
X =
5280
4
= 1320 𝑓𝑡
300mph = 440
𝑓𝑡
𝑠𝑒𝑐
P =
𝑀
𝑋
∗
𝑉3
3
=
4541 𝑙𝑏
32.2
𝑓𝑡
𝑠𝑒𝑐2 ∗1320 𝑓𝑡
∗
(440
𝑓𝑡
𝑠𝑒𝑐
)
3
3
= 3,033,601
𝑓𝑡−𝑙𝑏
𝑠𝑒𝑐
= 5515.42 HP
(c) How much time is required to cover the quarter mile?
∫ 𝑑𝑡
𝑇
0
=
𝑀
𝑃
∫ 𝑉 ∗ 𝑑𝑉
𝑉
0
10. T =
𝑀
𝑃
𝑉2
2
=
4541 𝑙𝑏
32.2
𝑓𝑡
𝑠𝑒𝑐2 ∗ 3,033,601
𝑓𝑡 − 𝑙𝑏
𝑠𝑒𝑐
(440
𝑓𝑡
𝑠𝑒𝑐
)2
2
= 4.5 𝑠𝑒𝑐
HW3
Q. You have been asked to help design the brake system on a new light truck. The truck
must meet FMVSS 105 performance requirements for deceleration (take this to mean 20
ft/sec2 lightly loaded, and 19 ft/sec2 fully loaded on an 81 Skid Number surface), as well
as corporate requirements for 0.25 g braking performance on a 30 Skid Number surface.
The important specifications of the vehicle are:
L=108.5” Rtire=13”
Brake gains (per wheel) 0.22 Nm/kPa (front) 0.15Nm/kPa (rear)
lightly-loaded fully-loaded
CG height 24" 24.4"
front axle weight 2491lbs 2558.63lbs
rear axle weight 2050lbs 2381.07lbs
You are to select a pressure proportioning system (break pressure and rise rate) and then
determine the efficiency of the system for the lightly-loaded and fully-loaded conditions. Do this
via the following steps:
11. (a) Calculate and plot the four performance triangles on the front/ rear brake force diagram
for all conditions. (Show your calculations for the intercept points.)
First step is to find the maximum front and rear brake forces for each condition.
𝐹𝑥𝑓𝑚 =
𝜇 𝑝(𝑊𝑓𝑠 +
ℎ
𝐿
𝐹xr)
1 −
𝜇 𝑝ℎ
𝐿
o Front brake force axis intercepts:
Lightly-loaded & 81 SN, 𝐹𝑥𝑓𝑚 =
0.81(2491𝑙𝑏𝑠 )
1−
0.81(24" )
(108 .5")
= 2458.1lbs
Fully-loaded & 81 SN, 𝐹𝑥𝑓𝑚 =
0.81(2558.63𝑙𝑏𝑠)
1−
0.81(24.4")
(108.5" )
= 2534.09𝑙𝑏𝑠
Lightly-loaded & 30 SN, 𝐹𝑥𝑓𝑚 =
0.3(2491𝑙𝑏𝑠)
1−
0.3(24" )
(108 .5")
= 800.42lbs
Fully- loaded & 30SN, 𝐹𝑥𝑓𝑚 =
0.3(2558 .63𝑙𝑏𝑠 )
1−
0.3(24.4")
(108.5")
= 823.12lbs
𝐹𝑥𝑟𝑚 =
𝜇 𝑝(𝑊𝑓𝑠 −
ℎ
𝐿
𝐹xr)
1 +
𝜇 𝑝ℎ
𝐿
o Rear brake force axis intercepts:
Lightly-loaded & 81 SN, 𝐹𝑥𝑓𝑚 =
0.81(2050𝑙𝑏𝑠)
1+
0.81(24" )
(108.5")
= 1408.19lbs
Fully-loaded & 81 SN, 𝐹𝑥𝑓𝑚 =
0.81(2381.07𝑙𝑏𝑠)
1+
0.81(24.4")
(108.5" )
= 1631.48𝑙𝑏𝑠
Lightly-loaded & 30 SN, 𝐹𝑥𝑓𝑚 =
0.3(2050𝑙𝑏𝑠 )
1+
0.3(24" )
(108 .5")
= 576.73lbs
14. Deceleration line
Lightly-loaded & 81 SN, Ftot = ma =
(2491lbs+2050lbs)
32.2𝑓𝑡
sec2
×
20ft
sec2 = 2820.5lbs
Fully-loaded & 81 SN, Ftot = ma =
(2558 .63lbs+2381.07lbs)
32.2𝑓𝑡
sec2
×
19ft
sec2 = 2914.73𝑙𝑏𝑠
Lightly-loaded & 30 SN, Ftot = ma =
(2491lbs +2050lbs)
32.2𝑓𝑡
sec2
× 0.25 (
32.2ft
sec2 ) = 1135.25lbs
Fully-loaded& 30S, Ftot = ma =
(2558 .63lbs+2381 .07lbs)
32.2𝑓𝑡
sec2
× 0.25 (
32.2ft
sec2 ) = 1234.93𝑙𝑏𝑠
Using calculator, find the intersection between the deceleration line and the force line.
Lightly-loaded & 81 SN, (297.43, 2523.07) and (1155.27, 1665.26)
Fully-loaded & 81 SN, (1397.71, 1517.02) and (311.31, 2603.42)
Lightly-loaded & 30 SN, (539.69, 595.56) and (312.60, 822.65)
Fully- loaded & 30SN, (631.00, 603.93) and (384.04, 850.89)
(b) Select the parameters for a proportioning valve (pressure break point and slope) to be
used and show it on the diagram
The diagram below shows the performance triangles for this vehicle. Since the brake
gains were given be proportioning line must have an initial slope of
0.22
0.15
= 1.467. this is
30SN,fully
loaded
823.12 669.17 0.0723 -0.0632 867.57 614.34
15. slope is satisfactory for the lower triangles, but must change a higher slope to meet the
high lower triangles.
It would be reasonable to select the pressure break point for the pressure proportioning
valve equivalent to 4003.4 N (900 lb) of force on the front brakes. The associated
pressure is:
𝑃𝑎 =
4003.4 𝑁∗ 0.33 𝑚
2 ∗ 0.22 𝑁 − 𝑚/𝐾𝑝𝑎
= 3002.55 𝑘𝑃𝑎
At this pressure the rear brake force is:
𝐹𝑟 =
2∗0.15 𝑁−
𝑚
𝐾𝑝𝑎
∗3002.55 𝐾𝑝𝑎
0.33 𝑚
= 2729.6 𝑁 = 613.64 lbf
A reasonable pressure proportioning can be obtained by choosing the second segment of
the line to go to a rear brake force of 6227.51 N (1400 lb) when the front brakes go up to
13345 N (3000 lb). The associated brake pressures at this condition are:
𝑃 𝑎𝑓 =
13345 𝑁 ∗ 0.33 𝑚
2 ∗ 0.22 𝑁 − 𝑚/𝐾𝑝𝑎
= 10008.75 𝐾𝑝𝑎
𝑃𝑎𝑟 =
6227.51 𝑁 ∗ 0.33 𝑚
2 ∗ 0.15 𝑁 − 𝑚/𝐾𝑝𝑎
= 6850.26 𝐾𝑝𝑎
The slope for the proportioning is:
S =
∆𝑃𝑎𝑟
∆𝑃 𝑎𝑓
=
6850.26 − 3002.55
10008.75 − 3002.55
= 0.549
The proportioning valve is denoted as
3002.55
0.549
%Graphing Front Brake Force Vs Rear Brake Force
% For lightly loaded & 81 SN,
fxr1=[1001.47 1408.19];fxf1=[2676.74 0];
plot(fxr1,fxf1);
hold on
fxr2=[0 1001.47];fxf2=[2458.14 2676.74];
plot(fxr2,fxf2);
% For fully loaded & 81 SN,
fxr3=[1199.83 1631.48];fxf3=[2801.33 0];
plot(fxr3,fxf3);
fxr4=[0 1199.83];fxf4=[2534.09 2801.33];
plot(fxr4,fxf4);
% For lightly loaded & 30 SN,
16. fxr5=[524.60 576.73];fxf5=[837.70 0];
plot(fxr5,fxf5);
fxr6=[0 524.60];fxf6=[800.42 837.70];
plot(fxr6,fxf6);
% For fully loaded & 30 SN,
fxr7=[614.34 669.17];fxf7=[867.57 0];
plot(fxr7,fxf7);
fxr8=[0 614.34];fxf8=[823.12 867.57];
plot(fxr8,fxf8);
%Drawing the deceleration line
fxr9=[297.43 1155.27];fxf9=[2523.07 1665.26];
fxr10=[1397.71 311.31];fxf10=[1517.02 2603.42];
fxr11=[539.69 312.60];fxf11=[595.56 822.65];
fxr12=[631.00 384.04];fxf12=[603.93 850.89];
plot(fxr9,fxf9);plot(fxr10,fxf10);plot(fxr11,fxf11);plot(fxr12,fxf12);
%Drawing the proportioning line
fxr13=[0 700]; fxf13=[0 1.467*700];
fxr14=[700 1400]; fxf14=[1.467*700 3000];
plot(fxr13,fxf13); plot(fxr14,fxf14);
xlabel('Rare Brake Force (lbs)'); ylabel('Front Brake Force (lbs)');
title('Brake Force Diagram');
hold off
17. (c) Calculate and plot the braking efficiency for the lightly-loaded and fully-loaded vehicle
as a function of application pressure for the design you selected.
Lightly loaded
Gf=0.22 Gr=0.15 R(tire)=0.33m Pa=3002.55kPa m(prop)=0.549
Wfs=2491lbs=11080.52N Wrs=2050lbs=9118.85N h=0.6096m WB=2.7559m
19. 5000 4001.28 6666.67 3637.52 0.469 1396.48 843.36 0.487 0.440 0.964 1.067 0.964
6000 4501.28 8000.00 4092.07 0.550 1437.48 802.36 0.567 0.520 0.970 1.059 0.970
7000 5001.28 9333.33 4546.61 0.632 1478.49 761.36 0.644 0.609 0.982 1.038 0.982
8000 5501.28 10666.67 5001.16 0.713 1519.49 720.36 0.716 0.708 0.996 1.008 0.996
9000 6001.28 12000.00 5455.70 0.794 1560.49 679.36 0.784 0.819 1.013 0.970 0.970
10000 6501.28 13333.33 5910.25 0.876 1601.49 638.36 0.849 0.944 1.032 0.928 0.928
11000 7001.28 14666.67 6364.80 0.957 1642.49 597.35 0.910 1.086 1.052 0.881 0.881
Conclusion
The following major assumptions that the team has made so far where included in the homework
problems and applied resulting not actual results:
Gross Vehicle Weight
Static Front Wheel Load(Rf)
0.000
0.200
0.400
0.600
0.800
1.000
1.200
0 2000 4000 6000 8000 10000 12000
Efficiency
Pressure (kPa)
Efficiency
Lightly-Loaded
Fully-loaded
20. Static Rare Wheel Load(Rr)
The Break gains, CG heights, and Horizontal location of passenger CG.
Last but not least, the project was one of the best ways to learn about real life vehicle. The group was
facing lots of problems. One of the problems that the group faced is identifying the vehicle, the
engine, and the tire ID. The group googled it and get the answer which states that the information
should be inside the hood behind the engine in a silver sticker. Also, measuring the value was one of a
kind experience to the group when trying to measure the lightly loaded and fully loaded.