Project bumper

8/19/2019 Project bumper

1/24

ABSTRACT

Automotive Design with economy, safety and aesthetics have been agreat challenge to design engineers. The safety of the passengers during

vehicle crashes can be ensured to a certain limit by using good bumpers.

A bumper is a shield, made of steel, aluminium, rubber, or plastic .It is a

horizontal bar fixed across the front or back of a motor vehicle to reduce

damage in a collision , but this proect is more inclined to off road

vehicles where It is not a safety feature intended to prevent inury to

occupants in the passenger cars but basically designed to protect the

hood, trunk, grill, fuel, exhaust and cooling system as well as safety

related e!uipment such as parking lights, headlamps and taillights in low

speed collisions during a rough road travel or "x" off road Driving..

In this work polystyrene coated steel bumper and a aluminium #$%& alloy

is compared with various factors by which the steel bumper has

advantages such as #etter 'trength, #etter Thickness, (ood towing

capacity and increasing the traction of the vehicles. The values of Impact

analysis are compared with the 'elected )aterial.


2/24

CHAPTER 1

INTRODUCTION.

WHAT IS OFF ROAD DRIVING ?

• *++ *ADI-( is raggy , uneven or an activity that includes steering

/ehicles or called 'ports utility /ehicles dirt tracks, mountain paths or

desert trails. It is pursued on terrain such as sand, gravel, snow, mud,

rock, grassland, riverbeds 0'hallow or Dry water1, and other natural

terrain 2 away from unpaved surfaces.• *ff3roading is done in all3terrain vehicles 0AT/s1, both four3 and two3

wheel, like "x"4s, eeps, snowmobiles, dirt bikes, !uad bikes, rock

crawlers and sand rails.

HISTORY OF OFF ROADING

• A +renchman by the name of Adolphe 56gresse was awarded with the

design of the world4s first off3road model.

• 56gresse designed a track in the style of a caterpillar, with a flexible belt,

which could be modified to a ordinary car or truck .

• A conventional eep, would have four3wheel drive, high3ground clearance

and low gearing. -owadays, there is a mind3boggling variety of off3road

vehicles out there for those people who like going on dirt, to choose from

both solidly heavy3duty and all3purpose light3duty.• *ff3roading events like the Dakar ally and the #aa 7&&& being among

the most famous. These events are a test of both navigational

competence and vehicle resilience power.

OFF ROADING IN INDIA

https://www.google.co.in/search?safe=off&q=define+competence&sa=X&ved=0ahUKEwjv9ufD_pvLAhVTCo4KHaHRBKwQ_SoIITAAhttps://www.google.co.in/search?safe=off&q=define+competence&sa=X&ved=0ahUKEwjv9ufD_pvLAhVTCo4KHaHRBKwQ_SoIITAA


3/24

• *ff3roading terrain, while 8adakh4s high3altitude desert offers e!ually

favourable conditions for the activity. *ut west in (uarat, the salt

marshes of the ann of 5utch make for a uni!ue off3roading experience.

• +ew *ff oad /ehicles opted for Indian oads7. )ahindra Thar

9. Toyota +ortuner

$. )itsubishi :aero 'port

ATTRIBUTES REQUIRED FOR OFF ROAD ING

• Heavy Duty Bumpers

• Ground Clearance

• Skid Plates

• Approach , brea!over " Departure A#$%es

• &hee% Art'cu%at'o#

• (o) E#* Tor+ue

• T'res

• H'$h ou#te* A'r I#tae

• Tow Points

• A Frame

1.1 WHAT IS A BUMPER

• A #umper is a shield made of 'teel, Aluminium, ubber, or :lastic

that is mounted on the front and rear of a passenger car.

• The e!uirement for new ustomised personal vehicles for

Adventure and other Activities have exponentially increased,

• A protective device which absorbs shocks and impeding contact.


4/24

7.9 NEED OF A BUMPER:

• During low speed collision occurs, the bumper system absorbs the shock

to prevent or reduce damage to the car.

• The Truck;ar bumper is designed to prevent or reduce physical damage

to the front and rear ends of passenger motor vehicles in low3speed

collisions especially in *ff oading.

• *ff oading #umpers are not typically designed to be structural

components that would significantly contribute to vehicle

crashworthiness or :assenger;occupant protection during front or rear

collisions.

• During a head on crash. The forward or the front side of the #umper folds

progressively and creates enough 'pace for the :assenger.

•


5/24

7.$ CLASSIFICATION OF BUMPERS

PLASTIC BUMPER - )ost modern cars use a reinforced thermoplastic

bumper, as they are cheap to manufacture, easy to fit and absorb more

energy during a crash.

BODYKIT BUMPER - )odified cars often now have a full body kit

rather than ust a front and rear bumper. These kits act as a skirt around

the entire body of the car and improve performance by reducing the

amount of air flowing underneath the car and so reducing drag.

CARBON FIBER BUMPER- arbon fibre body work is normally the

thing of super3cars, but many a car companies, and specialist modifiers,

are starting to use it for replacement body part on everyday cars.

STEEL BUMPER & ALUMINIUM BUMPER- This material worked

well, as it was very strong in a crash, 'teel bumpers are very heavy and

dented performance. Aluminium #umpers are light and have good

strength to weight ratio, but not strong as 'teel as car engine design has

improved, steel bumpers have pretty much shifted to off roading trucks.

Depending on the re!uirement of 'teel or Aluminium , the bumpers are

manufactured

7." COMPONENTS OF A BUMPER

There are different shapes, models and system for vehicle #umpers.

onventional models have corrugated open section areas for installing

some car elements and increasing bending strength of the bumper. )ain

parts of the conventional bumper systems are depicted.

• Fas!a: bumper fascia should have good aerodynamic and aesthetically

pleasing to the consumer but in *ff roading #umpers they are replaced

with 'teel or Aluminium.

• E"#$% a's($'#$s= energy absorbers are designed to absorb a portion of

the kinetic energy from vehicle collision. Its types include foam,

honeycomb and mechanical ones.


6/24

several times the weight of foam and honey comb absorber, they receive

limited usage.

• R#!")($!"% '#a*= )ain key component of the bumper and helps to

absorb the kinetic energy and give protection to the rest of the vehicle.

onfiguration of common bumper

7.> MATERIAL PROPERTIES RE+UIRED FOR DESIGN

'trength

Toughness

Ductility

?eldability

Durability.

)alleability

7.@ DEFINITION OF THE PROPERTIES

• S,$#"%, = the strength re!uired to cause permanent plastic deformation3

IB8D strength but till this point metal is undergoing elastic

deformation. Application of further load or stress will cause plastic

deformation and until the material can no longer withstand the stress

applied and ruptures, this point is called C8TI)ATB strengthCltimate strength of 'teel 3""& ):a

Cltimate strength of Aluminium 3$9& ):a

• T(%"#ss: defined as the work re!uired to deform one cubic inch of the

metal till it factures or it is the resistance of a material to being broken in

two,


7/24

suffer impact or for components where a fracture would be catastrophic

0pressure vessels, aircraft. Automotive parts1.

F($ E/= If a load is suddenly applied to a piece of mild steel and then to a

piece of glass the mild steel will absorb much more energy before failure

occurs. Thus, mild steel is said to be much tougher than a glass.

D,!0!,: Ductility is a measure of how much strain a given stress

produces and also property of a material enabled to drawn out into thin

wire on application of the load. )ild steel is a ductile material. The wires

of gold, silver, copper, aluminium, etc. are drawn by extrusion or by

pulling through a hole in a die due to the ductile property. The ductility

decreases with increase of temperature.

:ercent Blongation 0Bl1=

• W#0a'!0!,: ?elding is a process by which two materials, usually

metals, are permanently oined ,It is induced by a combination of

temperature, pressure, and metallurgical conditions .It is simply a

measure of how easy it is to make a weld in a particular material without

cracks. ?eldability is not a fixed parameter for a given material, but will

depend on oint details, service re!uirements, and welding processes and

facilities available.

Ma00#a'!0!,: )alleability of a material is its ability to be flattened into

thin sheets without cracking by hot or cold working. Aluminium, copper,

tin, lead, steel. are malleable metals. ability to plastically deform and

shape a material by forging, rolling or by any other method of applying

pressure. #eing easy to beat into a thin sheet is the literal meaning.


8/24

CHAPTER 2

During the 7%%&s, sport utility vehicles 0'C/s1 became the fastest growing

segment of the auto industry. In 7%%%, 'C/ sales reached almost 7% of the

total light vehicle market and the mix of 'C/s on the road was about E.F.

demand for new and customised personal vehicles were increasing at an

exponential rate with the increase in buying power of customers. As these 'C/s

were being used for different purposes namely in #attle fields, allies,

adventure , *ff oading etc. ?hen these trucks; 'C/s were driven on these

purposes they re!uired additional accessories or Cpgradation for #etter safety

of the truck as well as the passengers in the vehicle, ease of movement, (ood

towing capacity and increasing the traction of the vehicle.

'o this :roect is more narrowed down to design, model and manufacture a cold

rolled steel bumper for off road vehicles which can improve the above

mentioned factors. +inally this is done=

Stress -Stra'# curve o. '%*

stee%

Stress -Stra'# curve o.

A%um'#'um

:*#8B) DB+I-ITI*-


9/24

7. )aterial 'election

9. )odelling of the #umper

$. :roduction.

OB3ECTIVE OF THE PRO3ECT

• To determine the thickness of the -B? *++ *AD #C):B

• To design a -B? #C):B by )odeling in Cnigraphics -G E

• To carry out static analysis and impact Analysis on the -ew #umper to

and validate the results with the existing bumper in Impact Analysis.

9.9 METHODOLOGY

onceptual Design of the #umper

)odelling of the #umper

Development of (eometry from the

Bxisting #umper

)aterial 'election for the #umper

)echanical :roperties )eshing of (eometry

'imulation of the part

Impact 'trength for Bnergy Absorption Analysis of the esults

+inal )aterial selected from result

comparison

/alidation of the +inal bumper

esults and onclusion


10/24

CHAPTER 4

REVIEW OF LITERATURE

• arbon composites meets most of the e!uirements like high strength to

weight atio , rashworthiness and high stiffness to weight ratio, but

according to A0#" 3(" et.al H various aerodynamic shapes and structures

couldn4t be used due to high cost, )ore materials, composites and alloys

will used as materials in future. +urther analysis on environmental impact

can be done using the 8ife ycle Assessment software and carbon

calculator tools.

• Design, fabrication and testing of steel and composite bumper 0using

glass fibre material1 are completed and also composite bumper is

analysed and compared with steel bumper. K.C!"a$as5 #,.a0 has

discussed that fuel efficiency of the vehicle has increased as the weight

of the composite bumper is less compared to 'teel bumper.

• old3rolled and hot3dip galvanized steel grades with up to 7"&& ):a

tensile strength can be cold formed with conventional press forming and

roll forming methods. 3a"-O0() S6#$0# #,.a0 high strength and ultra high

strength sheet steels are today used successfully for weight reduction and

increased safety in applications such as door impact beams, bumper

reinforcements, and seat constructions.

The study of automotive bumper was done on designs namely, basic

bumper design with steel, with the attachment of foam and with the

attachment of honeycomb. P$a7##" K*a$89 #,.a0 concluded that

carbon fibre gives high strength to weight ratio in comparison with steel


11/24

and dissipates energy. The basic design with front part as a foam absorbs

the energy and ensures the pedestrian safety.

• S,a C. Da7!s8; found from 'urvey that 'C/s are safer than cars

because they are generally larger 0considered a weight advantage in

crashes with other vehicles1, higher 0improved visibility1, and more

rugged 0a vehicle that can climb mountains and cross streams of water

will surely be more than ade!uate on a city street1.According to crash

statistics indicate that large vehicles provide more protection than small

vehicles in crashes, there is no methodology to compare crash test results

across vehicle models in different size categories.

• G.N. RADU8s guide to safe and

common sense off oad Driving , he talks about )ag ?heels.


12/24

9.1 G#(*#,$! M(#0

• (eometric )odel is divided into

0a1.9D proection drawings

0b1.?ireframe )odelling

0c1.'urface )odelling

0d1.'olid )odelling

F%o) chart o. Geometr'c


13/24

• C("s,$,!(" () 'as! %#(*#,$! ('@#,s= In the very first step the

designer creates simple and basic geometric shapes and elements by

using options like points, lines, and circles.

• T$a"s0a,!("s () ,# sa6#s a" #0#*#",s= In the second step the

designer uses options like scaling, rotation and other related

transformations of the geometric shape and elements.

• C("s,$,!(" () ,# %#(*#,$! *(#0= During the last step the

designer makes use of various commands to that option which causes

integration of the obects or shapes sometimes called elements of the

geometric model to form the desired structure and shape.

• The onstruction can be saved in a file or location using a standard

0$D1 file format.

• (eometric modelling plays a maor role in cost by cutting down the

capital investment by creating in $d than physically.

• The )odels design or created can be directly used in )anufacturing

computer numerical control.

• +inite elemental analysis also accept these $D models to find out the

'tress, Thermal, Deflection etc.

WIREFRAME MODELLING

The word KwireframeL means a wire that is bent to follow the obect

edges to generate a model.

)odel consists entirely of points, lines, arcs and circles, conics, and

curves.

The obect is not recorded as a solid but the vertices that define4s the

boundary of the obect, or the intersections of the edges of the obect

boundary are recorded as a collection of points and their connectivity.


14/24

• haracteristics of ?ireframe modelling

♦ 'imple and straight forward in concept

♦ Displays less information than re!uired

♦ Ambiguous display of real obects will be created.♦ e!uires more user strain or effort to install the re!uired data.

• ?ireframe is divided into Analytical and 'ynthetic entities.

• This format cannot be used to calculate dynamic properties and

complex shapes curves cannot be modelled.

• /irtual edges are not provided.

SURFACE MODELLING

A surface model is a set of faces.

A surface model consists of wireframe entities that form the basis to

create surface. It contains the definitions of 'urface, edges and vertices.

Bliminates ambiguity and non3uni!ueness present in wireframe

models.

A wireframe model can be extracted from a surface model surface

model by deleting or blanking all surface entities deleting or blanking

all surface entities.

(ive4s the )odel a touch of better visualization and :resentations were

the obect looks very ealistic.

F'$ure o. )'re.rame

&'re.rame


15/24

It creates a surface (eometry for - )achining.

:roperties related to 'urfaces like eflectivity, colour and roughness

can be demonstrated and assigned.

'hape design and representation of complex obects such as car, ship ,and airplane bodies as well as castings.

It doesn4t provide useful information about the interior property of the

model as it is only 'urface construction.

'urface )odelling cannot be used to find out or calculate dynamic

properties.

SOLID MODELING

• It4s a three dimensional advanced (eometric modelling.

• 'olid :arts of an obect can be represented through solid modelling.

• The $D *bect can be viewed in wire frame, in turn wire frame for

better visualisation can be seen in 9D and $D.

• (iving surface :roection to the wire $D views of geometric models

makes the obect appear solid on the screen and this is called as solid

modelling.• 'olid )odelling is basically represented by volume.

• )ost importantly The solid modelling method is based upon the Mhalf3

spaceM concept.

• The boundary of the model differentiates the inside and outside of the

modelled obect.

• 'olid modelled obect stores both the geometric and topological data.

• Through 'olid modelling we can verify whether the 9 obects occupy

the same space or not.


16/24

• 'olid modelling improves the Design !uality and improvises the

visualization and has very good potential for functional automation

and integration.

• Csing volume information =• weight or volume calculation, centroids,

• moments of inertia calculation,

• stress analysis 0finite elements analysis1,

• heat conduction calculations,

• dynamic analysis, 2 system dynamics analysis.


17/24

• Csing volume an d boundary in formation=

• (eneration of - codes,

• obotic and assembly simulation.

• DI++BB-T '*8ID )*DB88I-( TB


18/24

o PARAMETRIC MODELLING= :arametric is a term used to describe

a dimension4s ability to change the shape of model geometry if the

dimension value is modified.

o F#a,$#-'as# is a term used to describe the various components of amodel. +or example, a part can consists of various types of features such

as holes, grooves, fillets, and chamfers.

o +eature3based, :arametric 'olid )odelling system represents the

progression of (eometric modelling.

o In parametric modeling, dimensions control the model.

o Design intent is how your model will react when dimension values are

changed.

o

+eature3based, parametric solid modelling eliminated the direct use of common geometric primitives such as cone, cylinder, sphere, etc, since

these primitives only represent low3level geometric entities. In designing

and manufacturing mechanical parts, one would always refer to

mechanical features.

o :arametric modeler software also provides tabular views of the

components 0parts list, door schedule, window schedule, etc.1 and

maintains their association with other views of the model. If a component

is edited graphically, the list is updatedO if a component is edited on thelist, the graphic views are updated.


19/24

SAMPLE MODEL OF A STEEL BUMPER

FRONT /IE& OF A BU0ER

ISOETRI1 /IE& OF A

BU0ER


20/24

MODELLING APPROACHES

There are two Different Approaches in creating a '*8ID )*DB8

o T(6 D(" A66$(a

o B(,,(* U6 A66$(a

TOP DOWN MODELLING:

o Bither volume or areas are considered to complete on single

solid part.

o ombination of these 'olid parts in a fashion finishes the final

'hape

o The volumes or areas that you initially define are called

primitives.

o :rimitives are located and oriented with the help of the working

plane.

o The combinations used to produce the final shape are called

#oolean operations.

o ?hen you create a 93D primitive, a modeling tool usually

defines an area, along with its underlying lines and key points.

o ?hen you create a $3D primitive, a modeling tool usually

defines a volume, along with its underlying areas, lines and key

points.

TO0 DO&N ODE((ING


21/24

BOTTOM UP MODELLING:

o Bither points or lines will be oined to complete the solid part.

o 8ow level programming systems usually adopts with bottom3up

modeling

o #ottom3up design is the traditional method. ou first #s!%" and

model parts, then insert them into an assembly and use mates to position the parts.

2!D pr'm't'ves '#c%u*e recta#$%es, c'rc%es,

tr'a#$%es, a#* other po%y$o#s

3!D pr'm't'ves4 b%ocs, cy%'#*ers, pr'sms,

spheres, a#* co#es5


22/24

BOTTO U0 ODE((ING


23/24

CHAPTER ;

;.1 MATERIAL SELECTION:

1. G$a# () (0 $(00# s,##0 CRCR99.

2. G$a# () A0*!"!* B 4.

;.2 STEEL VERSUS ALUMINIUM

• 'teel has higher density than Aluminium.• 'teel4s modulus of elasticity is greater than Aluminium.

• Aluminium has to have better thickness than 'teel to maintain its

stiffness property.

• 'teel is twice stronger than AluminiumO this strength role plays a critical

part during a collision or an impact action.

• Aluminium is almost three times costlier than 'teel in India.

• )aterial :roduction of 'teel and Aluminium , 'teel has an advantage

because Aluminium sheet :roduction is less

• Aluminium is complex to weld when its weldability is compared to 'teel

• Aluminium doesn4t have good 'tretch apability compared to 'teel this

property can be inferred from the 'tress3'train curve (raph.

• 'teel does have a very good preserving !uality, even after number of

load cycles, whereas Aluminium will be affected with +atigue and

eventually be destroyed.• Drilling holes of Aluminium is very intricate as compared to 'teel.

• +inally 'teel is easier to work under die;press and tooling. 'ecurity with

Aluminium needs much more engineering because itPs more prone the

shear, less tolerance to temperature change.

• 'o 'teel is a #etter )aterial than Aluminium to Design, model and

)anufacture #umpers for *ff oad Driving.


24/24

Project bumper

Documents

Transcript of Project bumper