Technical Bulletin

AE-MDB Specification
Version 1.0

29th April 2013
TB 014

TitleVersionDocument Number
AuthorDate
Related Documents
StatusApplication Date

AE-MDB Specification
1.0
TB014
James Ellway
29th April 2013
Euro NCAP Side Impact Testing Protocol
Information
January 2015

Copyright ©Euro NCAP 2013 - This work is the intellectual property of Euro NCAP. Permission is granted
for this material to be shared for non-commercial, educational purposes, provided that this copyrightstatement appears on the reproduced materials and notice is given that the copying is by permission ofEuro NCAP. To disseminate otherwise or to republish requires written permission from Euro NCAP.

Preface
In 2015 the European New Car Assessment Programme (Euro NCAP) will be updating its
side impact test procedure and assessment parameters. These updates will be centred on the
adoption of the WorldSID anthropometric test device and a new barrier face for the mobile
deformable barrier (MDB). This Technical Bulletin details the specification for the barrier
face and MDB.
Past European collaborative research involving government bodies, vehicle manufacturers
and test laboratories resulted in a prototype barrier face called the Advanced European
Mobile Deformable Barrier (AE-MDB). This barrier face offers a better representation of
the current accident situation and is a better reflection of front-end stiffness seen in today’s
passenger car fleet compared to that of the current legislative barrier face. Based on the
preliminary performance corridors of the prototype AE-MDB, a refined AE-MDB
specification has been developed by Euro NCAP with the barrier industry.
A programme of barrier to load cell wall testing was undertaken to complete andstandardise the AE-MDB specification. The programme was funded by four leading barrier
manufacturers to demonstrate that the specification was sufficiently well defined to allow
for the construction of reproducible barriers. In light of this, official Euro NCAP testingwith the AE-MDB (2015) may, until further notice, only be conducted using barrier faces
supplied by the following manufacturers (in alphabetical order):AFL Honeycomb Structures SARL
Cellbond Composites Ltd
Plascore, Inc
Showa Aircraft Industry Co., Ltd.

DISCLAIMER: Euro NCAP has taken all reasonable care to ensure that the information
published in this document is accurate and reflects the technical decisions taken by theorganisation. In the unlikely event that this protocol contains a typographical error or any
other inaccuracy, Euro NCAP reserves the right to make corrections and determine theassessment and subsequent result of the affected requirement(s).

EUROPEAN NEW CAR ASSESSMENT PROGRAMME (Euro NCAP)

AE-MDB Specification Version 1.0
Date of issue: 26th February 2013

Table of Contents
1.

CHARACTERISTICS OF THE MOBILE DEFORMABLE BARRIER ................................... 1

2.

CHARACTERISTICS OF THE IMPACTOR ............................................................................ 2

3.

VENTILATION SYSTEM ......................................................................................................... 7

4.

CONFORMITY OF PRODUCTION ......................................................................................... 8

5.

STATIC TESTS .......................................................................................................................... 96.

DYNAMIC LOAD CELL WALL TESTS ............................................................................... 10

7.

DESIGN OF THE IMPACTOR ............................................................................................... 15

8.

STATIC FORCE DEFLECTION CORRIDORS ..................................................................... 219.

DYNAMIC FORCE DEFLECTION CORRIDORS ................................................................ 23

1.

CHARACTERISTICSBARRIEROFTHE

MOBILEDEFORMABLE

1.1

The mobile deformable barrier (MDB) includes both an impactor and a trolley.

1.2

The total mass shall be 1300 ± 20kg.

1.3

The centre of gravity shall be situated in the longitudinal median vertical plane within
10mm, 1000 ± 30mm behind the front axle and 500 ± 30mm above the ground.

1.4

The distance between the front face of the impactor and the centre of gravity of the barrier
shall be 2000 ± 30mm.

1.5

The height of the barrier shall be such that the uppermost part of the front face of the beam
element (the intersection between the upper and lower row of blocks) is 550mm ± 5mm
above ground level measured statically prior to impact.

1.6

The front and rear track width of the trolley shall be 1500 ± 10mm.

1.7

The wheelbase of the trolley shall be 3000 ± 10mm.

Version 1.0
February 2013

1

2.

CHARACTERISTICS OF THE IMPACTOR

The impactor consists of six single blocks of aluminium honeycomb, which have beenprocessed in order to give a progressively increasing level of force with increasing deflection.
An additional single element is attached of 60mm depth to the front of the lower row ofblocks. Front and rear aluminium plates are attached to the aluminium honeycomb blocks.
The plates cover the angled surfaces.
2.1

Honeycomb blocks

2.1.1

Geometric characteristics

2.1.1.1

The impactor consists of six joined zones whose configuration and positioning are shownin Figure 1 and Figure 2. The principle dimensions of Blocks B and E are
500 ± 5mm x 250 ± 3mm and the principle dimensions and blocks A, C, D, F are
600 ± 5mm x 250 ± 3mm, Figure 2. The 500mm and 600mm should be in the W direction
and the 250mm in the L direction of the aluminium honeycomb construction, see Figure 3.

2.1.1.2

The impactor is divided into two rows. Both rows shall be 250 ± 3mm high and 440 ±2mm deep.

2.1.1.3

A 45 degree chamfer is applied to the outmost blocks on both the upper and lower rows.
The chamfer is not applied to the facing or backing plates of the beam element. See detail
A on Figure 2.

2.1.1.4

A bumper element is added to the front of the lower row, making the complete impactor
500 ± 2mm deep. The foil ribbon of this element will run parallel to the width dimension
and the cell axis running parallel to the height dimension. The 1220mm should be in the W
direction and the 200mm in the L direction of the aluminium honeycomb construction. See
Figure 3 .

2.1.2

Pre-crush

2.1.2.1

Pre-crushing only applies to blocks A, B, C, D, E & F not to the bumper element.

2.1.2.2

The pre-crush shall be performed on the surfaces of the honeycomb that are parallel to therear mounting face including the lower stepped section on Blocks D, E and F. Pre-crushingof the angled faces is not required.

2.1.2.3

All blocks (A, B, C, D, E & F) are to be pre-crushed by 10 ± 2mm on the front surface
prior to testing and shaping.

2.1.2.4

The angled faces on Blocks A, C, D and F should be cut after pre-crushing.

2.1.3

Material characteristics

2.1.3.1

The expansion direction of the Aluminium Honeycomb shall be as defined in Figure 3.

2.1.3.2

The cell dimensions shall be 19mm ± 10 per cent for all blocks A, B, C, D, E & F and6.35mm ± 10 per cent for the bumper section, see Figure 4.

2.1.3.3

All honeycomb blocks must be made of 3003 aluminium.

Version 1.0
February 20132

2.1.3.4

The aluminium honeycomb blocks (A, B, C, D, E & F) should be processed so that theforce deflection-curve when statically crushed (according to the procedure defined in
Paragraph 2.1.4) is within corridors to be defined for each of the six blocks in Section 5.

2.1.3.5

The aluminium honeycomb blocks for the bumper element should be processed so that thestrength is 1.586 to 1.793MPa when statically crushed (according to the procedure definedin NHTSA TP-214D).

2.1.3.6

The processed honeycomb material used in the honeycomb blocks to be used forconstruction of the barrier shall be cleaned in order to remove any residue that may havebeen produced during the processing of the raw honeycomb material.

2.1.3.7

The mass of the blocks in each batch shall not differ by more than 5 per cent of the mean
block mass for that batch.

2.1.4

Static tests for all blocks

2.1.4.1

A sample taken from each batch of processed honeycomb core shall be tested according to
the static test procedure described in Section 5.

2.1.4.2

The force-deflection characteristic for each block tested shall lie within the force
deflection corridors to be defined in Section 8.

2.1.5

Dynamic test

2.1.5.1

The dynamic deformation characteristics, when impacted, shall comply with the proceduredescribed in Section 6.

2.1.5.2

Deviation from the limits of the force-deflection corridors characterising the rigidity of the
impactor, as defined in Section 0 may be allowed provided that:

2.1.5.2.1

The deviation occurs after the beginning of the impact and before the deformation of the
impactor is equal to 150mm.

2.1.5.2.2

The deviation does not exceed 50 per cent of the nearest instantaneous prescribed limit of
the corridor.

2.1.5.2.3

Each deflection corresponding to each deviation does not exceed 35mm of deflection, andthe sum of these deflections does not exceed 70mm.

2.1.5.2.4

The sum of energy derived from deviating outside the corridor does not exceed 5 per centof the gross energy for that block.

2.1.5.3

The dynamic stiffness requirements for Block B is such that the force deflection curve falls
between corridors of Section 0, Figure 15.

2.1.5.4

The dynamic stiffness requirements for Blocks A and C are identical. Their rigidity issuch that their force deflection curves fall between corridors of Section 0, Figure 16.

2.1.5.5

The dynamic stiffness requirements for Block E is such that the force deflection curve falls
between corridors of Section 0, Figure 17.

2.1.5.6

The dynamic stiffness requirements for Blocks D and F are identical. Their rigidity is suchthat their force deflection curves fall between corridors of Section 0, Figure 18.

2.1.5.7

The dynamic stiffness requirement for the complete barrier is such that the force deflection
curve falls between corridors of Section 0, Figure 19.

Version 1.0
February 20133

2.1.5.8

The force-deflection curves shall be verified by a test detailed in Section 6 consisting of an
impact of the barrier against a dynamometric wall at 35 ± 0.5km/h.

2.1.5.9

The dissipated energy against blocks A and C during the test shall be equal to 5.0 ± 1.0kJ
per block.

2.1.5.10

The dissipated energy against block B during the test shall be equal to 4.6 ± 1.0kJ.

2.1.5.11

The dissipated energy against blocks D and F shall be equal to 14.8 ± 2.0kJ per block.

2.1.5.12

The dissipated energy against block E shall be equal to 17.3 ± 2.0kJ.

2.1.5.13

The dissipated total energy during the impact shall be equal to 61.5 ± 5.0kJ. The tolerance
takes into account any additional energy contribution from the rotating parts of the MDB.

2.1.5.14

The maximum impactor deformation from the point of first contact, calculated from
integration of the accelerometers according to Section 6.5.3 shall be equal to 346 ± 20mm.

2.1.5.15

The final residual static impactor deformation measured after the dynamic test at a heightof 425mm above ground and along the MDB centreline shall be equal to 340 ± 20mm.

2.1.5.16

The amounts of energy indicated are the amounts of energy dissipated by the system whenthe extent to which the impactor is crushed is greatest.

2.2

Front plates

2.2.1

Geometric characteristics

2.2.1.1

The three front plates (upper, lower & bottom) shall cover the full front surface of thebarrier and have a thickness of 0.5 ± 0.06mm. The three plates shall be 250mm, 200mm
and 50mm wide and of the appropriate length to cover the pre-crushed and angled surfaces
in a continuous length. The bottom strip (50mm wide) shall not cover the angled sides ofthe barrier.

2.2.1.2

When assembled the overall dimensions of the impactor shall be 1700 ± 2.5mm wide and
500 ± 2.5mm high. See Figure 2.

2.2.1.3

The upper edge of the lower front plate and the lower edge of the upper front plate shall bealigned within 4mm.

2.2.2

Material characteristics

2.2.2.1

The front plates are manufactured from aluminium of series AlMg2 to AlMg3 withelongation ≥ 12 per cent, and a UTS ≥ 175 N/mm2.

2.3

Bumper front and rear plates

2.3.1

Geometric characteristics

2.3.1.1

The geometric characteristics shall be according to Figure 1 and Figure 2.

2.3.2

Material characteristics

2.3.2.1

The bumper plates shall be manufactured out of aluminium 5251 H22, 5052 H32 or 5052
H34. The plates have a thickness of 3mm ±0.07mm.

2.4

Barrier back plate

Version 1.0
February 20134

2.4.1

Geometric characteristics

2.4.1.1

The geometric characteristics shall be according to Section 7.2.

2.4.1.2

The upper mounting flange shall be vertical. The lower mounting flange shall be bent
through 90 degrees.

2.4.2

Material characteristics

2.4.2.1

The back plate shall be manufactured from aluminium of series AlMg2 to AlMg3 withhardness between 50 and 67 HBS. The back plate is 3mm thick ±0.2 5mm. This plate shallbe perforated with holes for ventilation, the location, diameter and pitch are shown in
Figure 5 and Figure 7.

2.5

Location of the honeycomb blocks

2.5.1

The honeycomb blocks shall be centred on the perforated zone of the back plate.

2.6

Expanded polyester

2.6.1

Synthetic polyester thermo bonded wadding shall cover the chamfered zone of block A, C,
D & F as shown in Figure 1.

2.6.1.1

The material shall have a weight of 60g/m2 ± 20%.

2.6.1.2

The material shall provide a ‘soft link’ between the upper and lower row of blocks. It may
be added to the chamfered zone as a single piece or in multiple pieces provided thatdivisions are in the vertical direction only. The height of each piece is equal to that of thechamfered face.

2.7

Bonding

2.7.1

For both the front and the back plates, a maximum of adhesive film thickness of 0.5mm
shall be applied evenly over the surface of the front plate. The adhesive to be usedthroughout should be a two-part polyurethane, (such as Ciba Geigy XB5090/1 resin with
XB5304 hardener) or equivalent.

2.7.2

For the back plate the minimum bonding strength shall be 0.6MPa (87psi), tested
according to Section 2.7.3.

2.7.3

Bonding strength tests

2.7.3.1

Flatwise tensile testing is used to measure bond strength of adhesives according to ASTM
C297-61.

2.7.3.2

The test piece should be 100mm x 100mm, and 15mm deep, bonded to a sample of theventilated back plate material. The honeycomb used should be representative of that in theimpactor, i.e. chemically etched to an equivalent degree as that near to the back plate in thebarrier but without pre-crushing.

2.7.3.3

Back plate ventilation holes should be clean and clear of bonding material to enable freeflow of air.

Version 1.0
February 2013

5

2.8

Traceability

2.8.1

Barriers shall carry consecutive serial numbers which are stamped, etched or otherwise
permanently attached, from which the batches for the individual blocks and the date of
manufacture can be established.

2.9

Impactor attachment

2.9.1

The fitting on the trolley must be according to Figure 8. The fitting will use six M8 bolts,
and nothing shall be larger than the dimensions of the barrier in front of the wheels of thetrolley. Appropriate spacers must be used between the lower back plate flange and thetrolley face to avoid bowing of the back plate when the attachment bolts are tightened.

Version 1.0
February 2013

6

3.

VENTILATION SYSTEM

3.1

The interface between the trolley and the ventilation system should be solid, rigid and flat.
The ventilation device is part of the trolley and not of the impactor as supplied by the
manufacturer. Geometric characteristics of the ventilation device shall be according to
Figure 9 and Figure 10.

3.2

Ventilation device mounting procedure

3.2.1

Mount the ventilation device to the front plate of the trolley;

3.2.2

Ensure that a 0.5mm thick feeler gauge cannot be inserted between the ventilation device
and the trolley face at any point. If there is a gap greater than 0.5mm, the ventilation
frame will need to be replaced or adjusted to fit without a gapof > 0.5mm;

3.2.3

Dismount the ventilation device from the front of the trolley;

3.2.4

Fix a 1mm thick layer of cork to the front face of the trolley;

3.2.5

Re-mount the ventilation device to the front of the trolley and tighten to exclude air gaps.

Version 1.0
February 2013

7

4.

CONFORMITY OF PRODUCTION

The conformity of production procedures shall comply with those set out in the Agreement,
Appendix 2 (E/ECE/324-E/ECE/TRANS/505/Rev.2), with the following requirements:
4.1

The barrier manufacturer shall be responsible for the conformity of production proceduresand for that purpose must in particular:

4.1.1

Ensure the existence of effective procedures so that the quality of the products can beinspected;

4.1.2

Have access to the testing equipment needed to inspect the conformity of each product;

4.1.3

Ensure that the test results are recorded and that the documents remain available for a time
period of 10 years after testing;

4.1.4

Demonstrate that the samples tested are a reliable measure of the performance of the batch(examples of sampling methods according to batch production are given below);

4.1.5

Analyse results of tests in order to verify and ensure the stability of the barrier
characteristics, making allowance for variations of an industrial production, such astemperature, raw materials quality, time of immersion in chemical, chemical
concentration, neutralisation etc, and the control of the processed material in order toremove any residue from the processing;

4.1.6

Ensure that any set of samples or test pieces giving evidence of non-conformity gives rise
to a further sampling and test. All the necessary steps must be taken to restore conformityof the corresponding production.

4.2

The manufacturer's level of certification must be at least ISO 9001-2008 standard.

4.3

Minimum conditions for the control of production: the holder of an agreement will ensure
the control of conformity following the methods hereunder described.

4.4

Examples of sampling according to batch

4.4.1

If several examples of one block type are constructed from one original block ofaluminium honeycomb and are all treated in the same treatment bath (parallel production),
one of these examples could be chosen as the sample, provided that they are not shaped
and care is taken to ensure that the treatment is evenly applied to all blocks. If not, it may
be necessary to select more than one sample.

4.4.2

If a limited number of similar blocks (say three to twenty) are treated in the same bath(serial production), then the first and last block treated in a batch, all of which areconstructed from the same original block of aluminium honeycomb, should be taken as
representative samples. If the first sample complies with the requirements but the last does
not, it may be necessary to take further samples from earlier in the production until asample that does comply is found. Only the blocks between these samples should beconsidered to be approved. All samples must remain unshaped.

4.4.3

Once experience is gained with the consistency of production control, it may be possible tocombine both sampling approaches, so that more than one groups of parallel production
can be considered to be a batch provided samples from the first and last production groups
comply.

Version 1.0
February 2013

8

5.

STATIC TESTS

5.1

One or more samples (according to the batch method) taken from each batch of processedhoneycomb core shall be tested, according to the following test procedure:

5.1.1

The samples for all blocks (A, B, C, D, E and F) shall be 250mm x 500mm x 440mm.

5.1.2

The samples should be compressed between two parallel loading plates which are at least
20mm larger that the block cross section;

5.1.3

The compression speed shall be 100 millimetres per minute, with a tolerance of 5 per cent;

5.1.4

The data acquisition for static compression shall be sampled at a minimum of 5Hz;

5.1.5

The static test shall be continued until the block compression is at least 300mm for all
blocks (A, B, C, D, E and F);

Version 1.0
February 2013

9

6.

DYNAMIC LOAD CELL WALL TESTSFor every 200 barrier faces produced, the manufacturer shall make one dynamic test against a
dynamometric wall supported by a fixed rigid barrier, according to the method described
below.
6.1

Installation

6.1.1

Testing ground6.1.1.1

The test area shall be large enough to accommodate the run-up-track of the mobile
deformable barrier, the rigid barrier and the technical equipment necessary for the test.
The last part of the track, for at least five metres before the rigid barrier, shall be
horizontal, flat and smooth.

6.1.1.2

Fixed rigid barrier and dynamometric wall

6.1.1.3

The rigid wall shall consist of a block of reinforced concrete not less than 3 metres wideand not less than 1.5 metres high. The thickness of the rigid wall shall be such that itweighs at least 70 tonnes.

6.1.1.4

The front face shall be vertical, perpendicular to the axis of the run-up-tack and equippedwith a minimum of six load cell plates, each capable of measuring the total load on theappropriate block of the mobile deformable barrier impactor at the moment of impact. The
load cell impact plate area centres shall align with those of the six impact zones of themobile deformable barrier face. Their edges shall clear adjacent areas by 20mm ± 2mm
such that, within the tolerance of impact alignment of the MDB, the impact zones will notcontact the adjacent impact plate areas. Cell mounting and plate surfaces shall be inaccordance with the requirements set out in the annex to standard ISO 6487:1987.

6.1.1.5

The load cell wall must consist of at least 6 load cells, with the centre load cell having aloading surface area 500mm wide and 250mm high, and the outer load cells, covering
Blocks A, C, D and F, having a loading surface area 600mm wide and 250mm high. If
more than six load cells are used the aggregated area must be 500mm by 250mm at thecentre and 600mm by 250mm outside.

6.1.1.6

The area surrounding the load cells (<1700mm by <500mm) must have a surface common
to that of the load cell wall face for at least 150mm (>2000mm by >800mm). This isrequired to ensure that the barrier face is uniformly crushed and does not wrap around theedge of the load cells if the barrier impact is not in perfect alignment.

6.1.1.7

Surface protection, comprising a plywood face with a thickness of 18mm ± 5mm shall be
added to each load cell plate such that no degradation of transducer responses occurs.

6.1.1.8

The rigid wall shall be either anchored in the ground or placed on the ground with, if
necessary, additional arresting devices to limit its deflection. A rigid wall (to which theload cells are attached) having different characteristics but giving results that are at least
equally conclusive may be used.

6.1.1.9The load cells must align with the principle axes of the MDB face with Blocks B and Ealigned with the central load cells. The intersection of all blocks must align withintersections between load cells.

6.2

Propulsion of the mobile deformable barrier

Version 1.0
February 201310

6.2.1At the moment of impact the mobile deformable barrier shall no longer be subject to theaction of any additional steering or propelling device. It shall reach the obstacle on acourse perpendicular to the front surface of the dynamometric wall. The impact alignment
shall be accurate to within ± 15mm.

6.3

Measuring instruments

6.3.1

Speed

6.3.1.1

The impact speed shall be 35 ± 0.5km/h the instrument used to record the speed on impact
shall be accurate to within 0.1 percent.

6.3.2

Loads

6.3.2.1

Measuring instruments shall meet the specifications set forth in ISO 6487:1987

CFC for all blocks:
CAC for all blocks:

60Hz
100kN

6.3.3

Acceleration

6.3.3.1

The acceleration in the longitudinal direction shall be measured at three separate positions
on the trolley, one centrally and one at each side, at places not subject to bending.

6.3.3.2

The central accelerometer shall be located within 500mm of the location of the centre ofgravity of the MDB and shall lie in a vertical longitudinal plane which is within ± 10mmof the centre of gravity of the MDB.

6.3.3.3

The side accelerometers shall be at the same height as each other ± 10mm and at the same
distance from the front surface of the MDB ± 20mm

6.3.3.4

The instrumentation shall comply with ISO 6487:1987 with the following specifications:

CFC 1,000Hz (before integration)
CAC 50g
6.3.4

Contact timing

6.3.4.1

Two foil contact switches shall be fitted at the outboard ends of the face of the beam
element which contact the load cell wall first.

6.3.4.2

The contact switches must have a depth of 3mm or less.

6.4

General specifications of barrier and impactor

6.4.1

The individual characteristics of each mobile deformable barrier shall comply with
Section 1 of this specification and shall be recorded.

6.4.2

The suitability of an impactor as regards to the dynamic test requirements shall be
confirmed when the outputs from the six load cell plates each produce signals complying
with the requirements indicated in this specification.

Version 1.0
February 201311

6.4.3

Impactors shall carry consecutive serial numbers which are stamped, etched or otherwise
permanently attached, from which the batches for the individual blocks and the date of
manufacture can be established.

6.5

Data processing procedure

6.5.1

Raw data

6.5.1.1

At time T = T0, all offsets should be removed from the data. The method by which offsets
are removed shall be recorded in the test report.

6.5.1.2

T0 shall be established using the two contact switches fitted to the beam element.

6.5.2

Filtering

6.5.2.1

The raw data will be filtered prior to processing/calculations.

6.5.2.2

Accelerometer data for integration will be filtered to CFC 180, ISO 6487:1987.

6.5.2.3

Accelerometer data for impulse calculations will be filtered to CFC 60, ISO 6487:1987.

6.5.2.4

Load cell data will be filtered to CFC 60, ISO 6487:1987.

6.5.3

Calculation of MDB face deflection

6.5.3.1

Accelerometer data from all three accelerometers individually (after filtering at CFC 180),
will be integrated twice to obtain deflection of the barrier deformable element.

6.5.3.2

The initial conditions for deflection are:6.5.3.2.1

Velocity = impact velocity (from speed measuring device);

6.5.3.2.2

Deflection = 0;

6.5.3.3

The deflection at the left hand side, mid-line and right hand side of the mobile deformablebarrier will be plotted with respect to time.

6.5.3.4

The maximum deflection calculated from each of the three accelerometers should bewithin 10mm. If it is not the case, then the outlier should be removed and difference
between the deflection calculated from the remaining two accelerometers checked toensure that it is within 10mm.

6.5.3.5

If the deflections as measured by the left hand side, right hand side and mid-line
accelerometers are within 10mm, then the mean acceleration of the three accelerometers
should be used to calculate the deflection of the barrier face.

6.5.3.6

If the deflection from only two accelerometers meets the 10mm requirement, then themean acceleration from these two accelerometers should be used to calculate the deflection
for the barrier face.

6.5.3.7

If the deflections calculated from all three accelerometers (left hand side, right hand sideand mid-line) are NOT within the 10mm requirement, then the raw data should be
reviewed to determine the causes of such large variation. In this case the individual test
house will determine which accelerometer data should be used to determine mobile
deformable barrier deflection or whether none of the accelerometer readings can be used,

Version 1.0
February 201312

in which case, the certification test must be repeated. A full explanation should be givenin the test report.
6.5.3.8

T0 will be defined for both force and acceleration data using the two contact switches
placed on the beam element. Due to the effects of filtering, it is expected that force levels
at T0 will be above 0kN for the lower row of blocks. Force data must NOT be shifted toestablish 0kN at T0.

6.5.3.9

The mean deflection-time data will be combined with the load cell wall force-time data to
generate the force-deflection result for each block.

6.5.4

Calculation of energy

6.5.4.1

The absorbed energy for each block and for the whole MDB face should be calculated up
to the point of peak deflection of the barrier.
t1

En = ∫ Fn . dsmeant0

towhere:
t0
is the time of first contact
t1
is the time where the trolley comes to rest, i.e. where u = 0.
sis the deflection of the trolley deformable element calculated according
Paragraph 6.5.3.

6.5.5

Verification of dynamic force data

6.5.5.1

Compare the total impulse, I, calculated from the integration of the total force over theperiod of contact, with the momentum change over that period (M*∆V).

6.5.5.2

Compare the total energy change to the change in kinetic energy of the MDB, given by:

E K = 1 MV i 22
where:
Viis the impact velocity
M the whole mass of the MDB
6.5.5.3

If the momentum change (M*∆V) is not equal to the total impulse (I) ± 5 per cent, or if thetotal energy absorbed (Ε En) is not equal to the kinetic energy, EK ± 5 per cent, then thetest data must be examined to determine the cause of this error.

6.6

Post test

6.6.1

The crush of the AE-MDB should be recorded after the LCW impact at a representative
point on the barrier. The crush measurement shall be compared to the deflection calculated
from the trolley accelerometer data. If the calculated deflection is 20mm or more below thecrush measured after the impact, the individual test house will determine if any of the

Version 1.0
February 201313

accelerometer data can be used, in which case, the certification test must be repeated. A
full explanation should be given in the test report.

Version 1.0
February 2013

14

7.

DESIGN OF THE IMPACTOR

All dimensions are in mm.
7.1

Barrier face

7.1.1

The tolerances on the dimensions of the blocks allow for the difficulties of measuring cut
aluminium honeycomb. The tolerance on the overall dimension of the impactor is lessthan that for the individual blocks since the honeycomb blocks can be adjusted, withoverlap if necessary, to maintain a more closely defined impact face dimension.

Figure 1: Exploded isometric view of AE-MDB

Version 1.0
February 201315

Figure 2: AE-MDB dimensions

Figure 3: Aluminium honeycomb orientation

Version 1.0
February 201316

19mm ±1.9mm

6.35mm ±0.7mm
Figure 4: Dimension of Aluminium Honeycomb Cells

7.2

Back plate

Figure 5: Rear view of the back of the barrier faceVersion 1.0
February 201317

Figure 6: Attachment of backplate to ventilation device and trolley face plate

Figure 7: Staggered pitch for the backplate ventilation holes

Version 1.0
February 201318

7.2.1

Top and bottom back plate flanges

7.2.2

The attachment holes in the bottom flange may be opened to slots, as shown below, forease of attachment provided sufficient grip can be developed to avoid detachment during
the whole impact test.

Figure 8: Top and bottom AE-MDB mounting flanges

7.3

Ventilation frame

7.3.1

The ventilation device is a structure made of a plate that is 5mm thick and 20mm wide.
Only the vertical plates are perforated with nine 8mm holes in order to let air circulate
horizontally.

7.3.2

It is acceptable for ventilation frames that are 1500mm in with to be extended up to
1700mm in width provided that the correct pattern of venting and fixation is used.

Figure 9: AE-MDB trolley ventilation frame

Version 1.0
February 2013

19

Figure 10: AE-MDB trolley ventilation frame – side view

Version 1.0
February 2013

20

8.

STATIC FORCE DEFLECTION CORRIDORS

Force deflection corridors for quasi-static crush tests to test samples measuring 250 x 500mm
for all blocks.

B

D
A

A
B
C
D

Force
3.9kN
18kN
0kN
14kN

Deflection
6mm
240mm
11mm
240mm

Force
3.8kN
20kN
0kN
16kN

Deflection
6mm
240mm
11mm
240mm

C
Figure 11: Block B static corridor

B

D

A

A
B
C
D

C
A

Figure 12: Blocks A & C static corridor

Version 1.0
February 2013

21

C
B

F

A

E

D

A
B
C
D
E
F

Force
22.2kN
38.8kN
51.5kN10kN
31.5kN
41.5kN

Deflection
6mm
83mm
210mm
10mm
110mm
210mm

Force
19kN
41.5kN
9.5kN
32.5kN

Deflection
6mm
95mm
10mm
100mm

Figure 13: Block E static corridor

B

A

D

A
B
C
D

C

Figure 14: Blocks D & F static corridor

Version 1.0
February 2013

22

9.

DYNAMIC FORCE DEFLECTION CORRIDORS

Force deflection corridors for dynamic barrier to LCW tests.

B

D

E

A
B
C
D
E

Force
7kN
33kN
2kN
23kN
23kN

Deflection
50mm
300mm
80mm
300mm
330mm

A
B
C
D
E
F
G

Force
7kN
14kN
38kN
0kN
6kN
28kN
28kN

Deflection
60mm
130mm
300mm
74mm
130mm
300mm
330mm

A
C

Figure 15: Block B dynamic corridor

C

F

G

B
A
E
D
Figure 16: Blocks A & C dynamic corridor

Version 1.0
February 2013

23

A
B
C
D
E
F
G
H
I

Force
26kN
49kN
58kN
73kN
6kN
35kN
40kN
56kN
56kN

Deflection
10mm
135mm
135mm
240mm
10mm
165mm
165mm
260mm
330mm

A
B
C
D
E
F
G
H
I

Force
26kN
47kN
52kN
70kN
6kN
33kN
38kN
56kN
56kN

Deflection
10mm
135mm
135mm
300mm
10mm
165mm
165mm
300mm
330mm

A
B
C
D
E
F
G
H
I

Force
65kN
179kN
195kN
305kN
9kN
150kN
160kN
262kN
262kN

Deflection
10mm
135mm
135mm
270mm
10mm
165mm
165mm
300mm
330mm

D
C
I

H

B
G
A

F

E
Figure 17: Block E dynamic corridor

D
C
H

B

I

G

A

F

E
Figure 18: Blocks D & F dynamic corridor

D

H

I

C
B
G
F
A

E
Figure 19: Full barrier dynamic corridor
Version 1.0
February 201324

Version 1.0
February 201325