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Bernd Lorenz

Mobile Progressive Deformable Barrier and Mobile Rigid Barrier Tests – MPDB and MRB

Bundesanstalt für Straßenwesen

IWG R94

Geneva, 09. Dec. 2008

FI-3-10

• Background

• Tests

• Results

• Outcome

• Conclusions

Overview

Bernd Lorenz 2

• Conclusions

• Side effects

HypothesisIntroduction of PDB will lead to lower self protection

level in the vehicle fleet

Why?PDB can absorb much more energy than current ODB

Background

Bernd Lorenz 3

ConsequencesCars with reduced/shortened front-end deformation

zone can fulfil the PDB test but not the current R94

ODB test

-> Shortened front-end reduces the energy absorption

capabilities which leads to higher intrusion levels in the

car

“A “car” without front deformation zone (and less weight) can

fulfil the PDB test but not the R94-ODB test”

Test of hypothesis by performing 4 mobile barrier tests:

• Full-Width Movable PDB vs. PDB

• 60 km/h : 50 % Offset

• Full-Width Movable PDB vs. ODB

• 56 km/h : 40 % Offset

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• Movable Rigid Barrier vs. PDB

• 60 km/h : 50 % Offset

• Movable Rigid Barrier vs. ODB

• 56 km/h : 40 % Offset

• Mobile barrier (“car”)

• Front design: Rigid / PDB (“PDB looks like a car”)

• Mass:

• 1600 kg with PDB front

(Average of vehicle fleet structural database of VC-

Test Setup

Richard Damm 5

(Average of vehicle fleet structural database of VC-

Compat)

• 1450 kg without deformable element

• Width:

• 1750 mm (Average from VC-Compat database)

Full-Width Movable PDB vs. PDB

EES = 42.4 km/h

amax = 27.4 g Fmax = 430 kN

Full-Width Movable PDB vs. ODB

EES = 44.5 km/h

amax = 22.4 g Fmax = 351 kN

Calculations (statically)

09. Dec. 2008Bernd Lorenz 6

smax = 415 mm sbarrier = 415 mm smax = 591 mm sbarrier = 512 mm

Movable Rigid Barrier vs. PDB

EES = 0 km/h

amax = 38.9 g Fmax = 572 kN

smax = 0 mm sbarrier = 609 mm

Movable Rigid Barrier vs. ODB

The MRB still has 55 % of its kinetic

energy (74 % of its velocity) when the

ODB bottoms out.

Test 1 to 4

Troll. PDB - PDB

Troll. PDB - ODB

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Troll. rigid - PDB

Troll. rigid - ODB

Test 3, rigid-PDB Test 4, rigid-ODB

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Deceleration: PDB-PDB, PDB-ODB, Rigid-PDB, Rigid-ODB

-24

-12

0

Acce

lera

t io

n [g

]Results:

Bernd Lorenz 9

0 0.025 0.05 0.075 0.1Time [s]

-60

-48

-36

-24

Troll. PDB-PDB

Troll. PDB-ODB

Troll. Rigid-PDB

Troll. Rigid-ODB

Max. Acc. [g]

32

29

36

54

Comparison Force and (mass x acc)

-800-750

-700-650-600

-550-500

-450-400-350

-300-250-200

-150-100

-500

Fo

rce [

kN

]

PDB-PDB CFC60

Mass x Acc

Comparison Force and (mass x acc)

-800-750-700-650-600-550-500-450-400-350-300-250-200-150-100

-500

0 0,025 0,05 0,075 0,1 0,125

Fo

rce

[k

N]

PDB-ODB CFC60

Mass x Acc

Barrier Force

PDB-PDB PDB-ODB

Results:

-800

0 0,025 0,05 0,075 0,1 0,125

Time [s]

0 0,025 0,05 0,075 0,1 0,125

Time [s]

Comparison Force and (mass x acc)

-800-750

-700-650

-600-550

-500-450

-400-350

-300-250

-200-150

-100-50

0

0 0,025 0,05 0,075 0,1 0,125

Time [s]

Fo

rce

[k

N]

rigid-PDB CFC60

Mass x Acc

Comparison Force and (mass x acc)

-800-750-700-650-600-550-500-450-400-350-300-250-200-150-100-50

0

0 0,025 0,05 0,075 0,1 0,125

Time [s]

Fo

rce

[k

N]

rigid-ODB CFC60

Mass x Acc

Bernd Lorenz 10

Rigid-PDB Rigid-ODB

• For the barrier-barrier tests the deceleration levels are

higher than the values of the calculations (statically)

• For rigid-PDB test the acceleration level is lower than the

calculated value

• PDB can not detect rigid impactor

Outcome

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• ODB can detect rigid impactor, although

Rigid impactor vs. ODB has less initial speed, less

overlap, less mass -> 60km/h initial speed, 50% overlap,

equal mass to PDB impactor would further increase the

deceleration level

Conclusions

• PDB can absorb much more energy than current ODB

• Cars with reduced/shortened front-end deformation zone can

fulfil the PDB test but not the current R94 ODB test

Bernd Lorenz 12

-> Shortened front-end reduces the energy absorption

capabilities which is expected to increase intrusion levels in

the car

-> Introduction of PDB and cancellation of ODB will lead to lower

self protection level in the vehicle fleet

• Pros

• Mass reduction

• CO2 reduction

• Freedom to change Design

• Cons

Outlook/Side effects by stiffening/shorten front-ends

Bernd Lorenz 13

• Cons

• Pedestrian protection level decreases (-> WAD changes)

• Compatibility in side impact will be worse

• Self protection level will be decreased

• Compatibility in truck under-run situations will be worse

Thank you for your Attention!

Bernd Lorenz 14