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TRANSCRIPT
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
Bernd Lorenz 4
• 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
Bernd Lorenz 7
Troll. rigid - PDB
Troll. rigid - ODB
Test 3, rigid-PDB Test 4, rigid-ODB
Bernd Lorenz 8
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
Bernd Lorenz 11
• 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