Novel Offset Deformable Barrier leading to changes in European Standards and improved vehicular safety
Submitting InstitutionAnglia Ruskin University
Unit of AssessmentGeneral Engineering
Summary Impact TypePolitical
Research Subject Area(s)
Mathematical Sciences: Applied Mathematics
Engineering: Automotive Engineering, Materials Engineering
Summary of the impact
Research into variable mechanical energy absorption, using Finite Element
(FE) modelling and
analysis, funded by Cellbond Ltd., led to a design specification for an
Offset Deformable Barrier
(ODB). Such barriers are used within the motor manufacturing industry to
test vehicular safety.
Based on the findings of our research, the barrier used in car crash tests
has been redesigned.
The design specification for the barrier has been adopted by the European
New Car Assessment
Programme (EuroNCAP). All newly designed cars are tested with this type of
barrier before they
enter production. The use of FE modelling and virtual crash testing allows
barriers to be designed
with particular properties and for the crash testing cycle to be
Research using FE modeling of variable energy absorption by honeycomb
materials, at Anglia
Ruskin University, dates back to 1996. Such research involves modeling of
properties of materials and engineering products for the development and
composite structures. One application of such structures is testing of
impact absorption as applied
within the automotive industry. The behaviours of the crash test barriers
and prototype cars can be
predicted using the FE models and then tested experimentally for
verification of the results. The
designs of the barriers are then refined prior to entering production. In
this case study, FE analysis
has been applied to the design of an ODB  used in frontal and offset
impact tests according to
the specifications developed for the Federal Motor Vehicle Safety
Standards (FMVSS), EuroNCAP,
Australian New Car Assessment Programme (Australian NCAP), Japanese New
Programme (JNCAP) and the Insurance Institute for Highway Safety (IIHS).
specifically provides the methodology to create the advanced dynamic FE
model of the ODB and
support its subsequent certification. The research uses LS-DYNA as the
analysis tool to create the
model. Static compressive tests, at different angles of impact, provide
the necessary information to
construct the aluminium honeycomb material cards within the barrier. The
research also models
the dynamic stiffening of the honeycomb during the simulation by
generation of strain-rate scale
factor curves. Adhesive properties are obtained using Climbing Drum,
T-Peel, Tensile and Plate
Shear test results. In all assessments, the barriers are mounted on a
rigid wall and tested at certain
impactor speeds [2-4].
Additionally, to construct realistic FE models in this research,
specially adapted material cards,
allowing shear forces to be considered in the models and measured in the
real tests, were
incorporated into the barrier along with solid elements. This allowed the
simulation and testing of a
compartmentalized vehicular front section. This was the first time that
simulation and testing was possible. This facilitated the design and
manufacture of a crash test
barrier with specific properties to enable, for the first time, simulation
of vehicles of different types.
Ultimately the design based upon FE models and experimental data has been
EuroNCAP and most motor manufacturers. EuroNCAP is the recognized
institution for defining and
rating car safety standards, which are recognised benchmarks for all car
safety tests. The crash
test barrier manufactured by Cellbond is now sold globally and used by
most motor manufacturers.
The work, involving identifying the material from which the ODB must be
manufactured, its crush
strength, foil thickness and honeycomb cell size, began in 1996, led by
Professor Hassan Shirvani
(Anglia Ruskin University), along with collaborators at Cellbond through a
Scheme Programme. This was followed up in 1998 through a KTP programme
Shirvani, KTP Associate - Paul Owen). The work led to the successful
submission of a patent in
2002, which was granted in 2005 and which was subsequently purchased by
Cellbond in 2006. In
2006, a Cellbond-funded PhD studentship was awarded to Asadi, which was
completed in 2011
and through which the design of the barrier was completed.
The barriers were modelled at Anglia Ruskin University and Cellbond in
collaboration with ARUP
[4-7] and Jaguar-Landrover.
Key researchers were Professor Hassan Shirvani (research group leader and
September 1996 - February 2001; Professor March 2001 to date), Dr. Ayoub
October 2001 - July, 2008; Senior lecturer August 2008 to date) and Dr.
Habtom Mebrahtu (Senior
Lecturer September 2000 - February 2010; Principal Lecturer February 2010
References to the research
2.M. Asadi, B. Walker (2011) "Application of Shell Elements to Create
Element Model for Offset Deformable Barrier", Int. J. Vehicle Structures
& Systems, 3, 139
- 143. Available in REF2.
3. M. Asadi, I. Bruce, H. Shirvani (2009) "An Investigation to Compare
the Application of Shell
and Solid Element Honeycomb Model in ODB", 7th European LS-DYNA
Available on demand from the HEI.
4. M. Asadi, B. Walker, H. Shirvani (2008) "Development of the Advanced
Finite Element Model
for ODB Impact Barrier", Japan LS-DYNA User Conference. Available on
demand from the
5. Sh. S. Esfahlani, H. Shirvani, A. Shirvani, S. Nwaubani, H. Mebrahtu
and C. Chirwa (2013)
"Hexagonal honeycomb cell optimization by way of meta-model techniques"
Int. J. of
Crashworthiness, 18, 264 - 275. Available in REF2.
6.Sh. S. Esfahlania, H. Shirvani, A. Shirvani, H. Mebrahtu, S. Nwaubani
development and numerical analysis of honeycomb core with variable
American J. of Engineering and Applied Sciences, 6, 8 - 19. Available in
7. Sh. S. Esfahlania; H. Shirvani, A. Shirvani, S. Nwaubani, H. Mebrahtu
study of Honeycomb optimization using Kriging and Radial Basis Function"
J. of Theoretical
and Applied Maths Lett. 3. Available via DOI: 10.1063/2.1303102
Details of the impact
Road safety is now more important to policymakers and the public than
ever before. In 2004, road
accident deaths stood at 43,500 in the European Union (source: CARE
database) and around
42,600 in the US (source: FARS database), with hundreds of thousands more
road users suffering
serious injuries. The crashworthiness of a vehicle is regulated by
legislation such as ECE R94,
R95, FMVSS 201, 208 and 214 for occupant protection. Vehicle safety
ratings and new car
assessment programmes have also increased public awareness of these design
such programmes the public are informed about the occupant safety of new
Manufacturers are also placed under increasing pressure to increase
occupant safety. Such
features are widely used as a marketing tool.
The test protocols designed by EuroNCAP of (i) offset frontal impact and
(ii) side impact are
designed to represent the most severe test that a car can undergo in terms
protection. It is therefore essential that the tests are fit for purpose.
Before the design of the ODB, the crash test was carried out using two
car bodies (shells).
However, the criticism of this type of test is that crashes between two
identical cars are very rare.
Additionally, the shells were not manufactured from materials with
properties representing the different compartments on the front of a car.
This means that the car
fronts were not truly represented. What was required was a crash test
barrier that could represent
a generalised car structure into which different car makes could be
crashed, thus mimicking with
greater accuracy "real life". Additionally, different parts of the crash
test barrier would have to be
designed to absorb different amounts of energy mimicking the
compartmentalised structure (e.g.
chassis, bonnet, wing, bumper) of the front of a motor vehicle.
The research work on the design and modelling, initiated at Anglia
Ruskin, and implemented at
Cellbond, allowed for the first time a crash test barrier that more
closely mimics the front of a
generalised motor vehicle. The properties of the barrier can be modelled
and its crash test
behaviour predicted allowing the honeycomb to be "tuned" to behave like
the front of a car of a
desired type. Additionally the modelling allows new data to be collected.
In the old test only the
impact perpendicular to the front of the car was considered. With the
availability of the finite
element modelling and the honeycomb structure, the shear forces involved
(non perpendicular to
the car front) can also be considered for the first time. This allows
greater understanding of the
behaviour of the front of the car being tested in the crash situation.
The barriers were tested and adopted by Cellbond-MIRA (Motor Industry
the Transport Research Laboratory and EuroNCAP. Following on from this,
they were trialled and
approved by the National Highway Traffic Safety Administration. As a
consequence of this and the
requirement for crash tests to be employed for all new models of motor
vehicle, these new barriers
have been adopted widely across the motor vehicle manufacturing industry.
these barriers. The global market for these barriers represents a
significant increase in commercial
income and opportunity for the company.
The significance of the impact resulting from this research is therefore
(i) For the first time the ODB can be tuned to represent the front of a
car of a specific type;
(ii) The shear forces involved in a crash situation in terms of car and
barrier behaviour can
be understood for the first time;
(iii) This is the first time that a heterogeneous crash situation can be
modelled and tested
increasing the range of crashes that can be simulated and understood;
(iv) Safer and more robust cars can be designed and manufactured
Sources to corroborate the impact
- Director of Group Operations, ENCON CAM / Cellbond.
- 17th ESV Conference 2001, EURONCAP - Views and Suggestions for
This document discusses the crash test, the technical specifications
for the barrier and states that the
Cellbond barriers are used for the test.
This document explains the Euro NCAP test method for assessing frontal
impact, including reference to and
description of the ODB.