International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 5- Dec 2013
Impact Analysis of Front Bumper
Mr. Nitin S. Motgi
Prof. S. B. Naik
Prof.P.R.Kulkarni
ME Design –II, Walchand Institute
of Technology,
Solapur (India)
Associate Professor, Walchand
Institute of Technology, Solapur
(India)
Associate Professor, Walchand
Institute of Technology, Solapur
(India)
ABSTRACT
the hood, trunk, grill, fuel, exhaust and cooling system as
Automotive industry is a very huge ground and research is
well as safety related equipment such as parking lights,
still evolving. From this safety and comfortness of
headlamps and taillights, etc [1]. A good design of car
passenger car is very important. Hence the researchers
bumper must provide safety for passengers and should
have to be focused on safety and comfortness. In tune
have low weight [2]. Different countries have different
with this improvement in the design of a bumper is very
performance
important. This will increase the performance of the
International safety regulations originally developed as
bumper, improve absorbing capacity during impact load
European standards and now adopted by most countries
and increase the protection of the front car component.
outside North America, a car's safety systems still
This research aims towards improvement in the design of
function normally after a straight-on pendulum or
front bumper of passenger car and gives the economical
moving-barrier impact of 4 km/h (2.5 mph) to the front
solution for the front bumper material by emphasizing the
and the rear, and to the front and rear corners of 2.5 km/h
cost reducing aspect. The methodology employed
(1.6 mph) at 45.5 cm (18 in) above the ground with the
includes study of front bumper system, design and
vehicle loaded or unloaded. In North America (FMSS:
analysis of the improved front bumper using CAD/CAE
Federal Motor Vehicle Safety Standards) and Canada
softwares.
(CMVSS: Canadian Motor Vehicle Safety Standards), it
standards
for
bumpers.
Under
the
should be meet 4KMPH pendulum and barrier impacts [3].
Keywords-Impact, bumper, CAD, FEA
The function of automotive bumpers has changed
considerably over the past 70 yrears. The later
1. INTRODUCTION
performance is achieved by a combination of careful
Car accidents are happening every day. Most drivers are
design, material selection to obtain a particular balance of
convinced that they can avoid such troublesome situations.
stiffness, strength and energy absorption. Stiffness and
However the statistics shows that ten thousand dead and
Energy absorption are essential criterion. Stiffness is
hundreds of thousands to million wounded each year.
important because vehicle design consideration limits the
Hence, improvement in the safety of automobiles is
packaging space for the bumper design to deform under
prerequisite to decrease the numbers of accidents.
load and Energy absorption is important because bumper
Automotive bumper system is one of the key systems in
must limt the amount of the impact force transmited to
passenger cars. Bumper systems are designed to prevent
the surrounding rails and vehicle frame. Automotive
or reduce physical damage to the front or rear ends of
bumper plays a very important role in absorbing impact
passenger motor vehicles in collision condition. It protects
enegry (original purpose of safety) and styling stand
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International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 5- Dec 2013
point/aesthetic purpose. Now a days ,automotive industry
3. STANDARDS FOR BUMPER
concentrates on optimisation of weight and safety.
In most jurisdictions, bumpers are legally required on all
2. LITERATURE
vehicles. The height and placement of bumpers may be
Literatures related to impact are studies by many
researchers. It was observed that, major injury due to
impact velocity of around 20-30 kmph was affected to the
legally specified as well, to ensure that when vehicles of
different heights are in an accident, the smaller vehicle
will not slide under the larger vehicle.
knee ligament. Davoodi et al. [4] proposed conceptual
3.1 International standards
design of fiber reinforced epoxy composite bumper
Under the International safety regulations originally
absorber as a pedestrian energy absorber. The energy
developed as European standards and now adopted by
absorption capacity was sufficient for pedestrian impact
most countries outside North America, a car's safety
and it could possible to use as substitute for the existing
systems must still function normally after a straight-on
materials such as EPP foam for low impact collision.
pendulum or moving-barrier impact of 4 km/h (2.5 mph)
Mohapatra S [5] discussed that automotive development
to the front and the rear, and to the front and rear corners
cycles are getting shorter by the day. With increasing
of 2.5 km/h (1.6 mph) at 45.5 cm (18 in) above the ground
competition in the marketplace, the OEM’s and suppliers
with the vehicle loaded or unloaded.
main challenge is to come up with time-efficient design
3.2 India [7]
solutions. Researchers are trying to improve many of
India is the 10th largest producer of automobiles in the
existing designs using novel approaches. Many times
world.
there is conflicting performance and cost requirements.
requirements has progressed significantly since the year
This
and
2000. More than 35 million vehicles are registered in
Development units to come up with a number of
India. In 1989, the Central Motor Vehicle Rules (CMVR)
alternative design solutions in less time and cost
became effective and the rules are greatly enforced today.
compared to existing designs. These best solutions are
Under Rule 126 of the CMVR, manufacturers of motor
best achieved in a CAE environment using some of the
vehicles must allow a separate agency to test prototypes of
modern CAD and FEM tools. Such tools are capable of
new vehicle designs for safety requirements. It is
effecting quick changes in the design within virtual
necessary for all vehicles in India to have basic safety
environment.
features, such as seat belts, rear-view mirrors and
puts
additional challenge for
Research
Andersson R et.al [6] emphasized that to
increase crash performance in automotive vehicles it is
necessary to use new techniques and materials. The
components that are linked to crash safety should transmit
or absorb energy. The energy absorbing capability of a
specific component is a combination of geometry and
material properties. The chosen material should have high
yield strength and relatively high elongation to fracture.
These demands lead to increase
strength stainless steels.
interest to use of high
The
country's
attention
to
vehicle
safety
laminated safety glass for windshields. Also, all vehicles
in use must pass a pollution test every six months.
4. MODELLING AND ANALYSIS
From literature review it is clear that automotive bumper
has evolved over the years. Although it is evolved
ergonomically there is no systematic study which explains
design and analysis of front bumpers in the presence of
solid mechanics using advanced FEA tools.
4.1 Modelling
This section discusses CAD modelling approach followed
in the various parts/components and assembly of front
bumper. Modelling of front bumper and its component is
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International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 5- Dec 2013
carried out using CAD software. Keeping objectives in
reasonable time frame with reasonable effort. The FEM is
mind, existing bumper systems of different passenger cars
one such approximate solution technique. Fig.2 shows the
have been studied. Moreover, evolution of bumper system
CAD model of bumper system.
is also studied. There is trade off between weight and
performance. Initially, most of the cars used metallic
bumper systems with or without energy absorbing
materials like rubber, foam, etc. This kind of design
increases weight and number of parts in assembly.
Recently, there is emphasis on use of composite materials
like G-epoxy. This has reduced weight further and it is
observed that composite materials are also capable to
absorb energy along with a simplified geometry. Hence,
present
research
includes
study
of
following
configurations of fascia and presents different designs in
terms of reducing weight and increasing the performance.

Foam-absorber
type
bumper
assembly
Fig. 2 CAD model of bumper system
Fig, 3 shows meshed model of bumper system. Meshing
is nothing but converting a whole geometry into number
of elements and these elements are connected by nodes.
with
Aluminum fascia. (configuration 1)

Modified absorber type bumper assembly with
composite fascia.(configuration 2)
Fig. 3 Meshed model of bumper
The number of nodes and elements that are used are
23033 and 7120 respectively. To carry out impact analysis
Fig. 1 Foam-absorber type bumper assembly with
of bumper system within framework of FEA, this is low
speed impact(4kmph) and as per standards bumper should
Aluminium fascia
withstand it. Appropriate contacts have been defined at
4.2 Finite Element Method
Many problems in engineering are governed by
differential or integral equations. The solution to these
appropriate locations between different parts. Fig. 4
shows loads and boundary conditions.
equations would provide an exact, closed-form solution to
these equations to the particular problem being studied.
However, complexities in geometry & in boundary
conditions that are seen in most real world problems
usually means that an exact solution cannot be obtained or
obtained in real time. But current product design cycle
times imply that engineers must obtain design solutions in
Fig. 4 Loads and boundary conditions
a short amount of time. They are content to obtain
approximate solutions that can be readily obtained in a
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International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 5- Dec 2013
The given configuration of bumper system is solved using
LS DYNA solver with inputs as discussed. Post
processing involves the review of various results such as
stresses and deformations.
Fig. 9 Internal energy of aluminium bumper fascia
Fig. 5 Stresses in bumper system of aluminium material
Fig. 10 Internal energy of composite bumper fascia
5. CONCLUSION
Fig. 6 Stresses in bumper system of Composite material
The stress pattern within bumper system has been
studied. Depending on outcome, metallic and composite
bumper facia are selected for impact strength assesment.
Finally, it is found that composite facia is suitable from
impact point of view and which is comman now.
AKNOWLEGEMENT
Fig.7 Deformation in aluminium bumper fascia
I take this opportunity to express my gratitude to
the people who have been instrumental in the successful
completion of this work. At the outset I articulate my
overwhelmed feelings towards my guide Prof. S. B. Naik
for being my teacher and providing confidence to carry
out my research work.
I am grateful to Dr. S. A. Halkude, Principal,
Dr. K. H. Jatkar, Head of Mechanical Engineering
Fig. 8 Deformation in composite bumper fascia
Fig. 9 and 10 shows internal energies for bumper
fascia made of aluminium and composites.
Internal
energies are indicator of energy absorption characteristic
of fascia. From energy characteristics it appears that
aluminium
fascia
has
poor
energy
absorption
characteristics when compared with composite fascia.
ISSN: 2231-5381
Department, for allowing me to pursue this research work.
I express my deep sense of appreciation to Prof.
P.R.Kulkarni for his unrelenting help and moral support
throughout the research work.
I thanks to my parents for giving me the innate
abilities that I have. I wish to recognize the moral support,
proof reading and lively cooperation of my friends.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 5- Dec 2013
REFERENCES
[1] Hosseinzadeh RM, Shokrieh M, and Lessard
LB,“Parametric study od automotive composite
bumper beams subjected to low-velocity impacts”, J.
Composite Stuct., P P 419-427, 2005
[2] Marzbanrad J M, Alijanpour M, and Kiasat MS,
“Design and analysis of automotive bumper beam in
low speed frontal crashesh”, Thin Walled Struct., P
P 902-911, 2009.
[3] http://www.nhtsa.dot.gov/cars/testing/procedures/TP
-581-01.pdf
[4] M.M Davoodi, S.M Sapuan, R. Yunus.. “Conceptual
design of a polymer composite automotive bumper
energy absorber”. Elsevier Ltd 2007
[5] Mohapatra
Automotive
S,
“Rapid
Bumper
Design
Solutions
Energy Absorbers
for
using
Morphing Technique”, Altair CAE users Conference,
Bangalore, India. 2005.
[6] Andersson R, Schedin E, Magnusson C, Ocklund J,
“The Applicability of Stainless Steel for Crash
Absorbing Components”, SAE Technical Paper,
2002.
[7] https://www.araiindia.com/
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