From the numerical simulations to on-site tests: what have to be done? - Focus on straight lines
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From the numerical simulations to on-site tests:
what have to be done?
Focus on straight lines
Lab tests, selection and production of new components, tests sites selection
Training Workshop WP1 / WP3, 22d May 2013
Estelle BONGINI 1
Which systems to be tested?
CONCLUSIONS FROM THE NUMERICAL STUDY
• About under sleeper pads:
– Two means of action: they reduce the wheel-rail interaction force and they
increase the track receptance
– The softer they are, the more efficient in the low frequency range
– Use with large/heavy sleeper allows the same efficiency with limited track
deflexion at the contact point
• About the very soft railpads:
– One major way of action: they reduce the wheel-rail interaction force
– The softer they are, the more efficient in the low frequency range
Estelle BONGINI 2
Which systems to be tested?
Ballasted straight line
Mitigation solutions tested are of 2 types:
• Soft under sleeper pads with heavy sleepers to be tested on a
test rig, 5 different combination of USP + heavy sleepers
• Soft to very soft rail fastening systems to be tested on
commercial freight corridor, 2 different systems
+ 1 system to be let 2 years on track in soft configuration
Long term behaviour
Effect on unevenness growth and parametric excitation growth
Slab track
• Soft under sleeper pads with heavy sleepers to be tested for
GETRAC slab systems, on a test rig
Estelle BONGINI 3
Components designs / USP • Different under sleeper pads presenting various static / dynamic stiffness • Combined with heavy sleepers specifically designed by RailOne for RIVAS Design and production phase of these specific components presented by Wojciech Nawrat Estelle BONGINI 4
Components design / URP
• 2 different systems to be tested, proposed by Pandrol:
– DFC: rail pads + under baseplate pads
– VANGUARD system
• These 2 systems have to be tested on the same trial zone: they require to be
installed on the same sleepers
Dedicated sleepers specifically designed by SATEBA,
to support both system
Dedicated DFC system, adapted to these sleepers
Estelle BONGINI 5
Lab tests related to track mitigation solutions implementation Estelle BONGINI 6
Component characterization / USP
CHARACTERIZATION of COMPONENTS
BAM has tested in lab various sets of {sleepers+USP} and the heavy sleepers
Tests performed on the USP:
Static and dynamic Bedding modulus
specimen, concrete block with USP
The static bedding modulus is used for the calculation of the static
compression of the rail under the service load
The low frequency bedding modulus Cdyn1 (f) is used for the
calculation of the bending deformation of the rail under a rolling
wheel. It determines the superstructure dynamics
The high frequency bedding modulus Cdyn2 (f) is determined for
under-sleeper pads which shall reduce structure-borne noise. It
characterises the mitigation potential of the under-sleeper pad
Tests protocols and results detailed in RIVAS Del 3.7 Test rig for small components (KPM), static and
low frequency bedding modulus
Estelle BONGINI 7
Component characterization / USP
Fatigue test
The mechanical fatigue strength test shall characterize the long term
functionality of the USP and the bonding layer
Bond strength by pull out
The bond strength by pull-off shall be determined to ensure the required degree
of the bonding between under sleeper pad and concrete
Shear test
Frost-thaw test
Tests protocols and results detailed in RIVAS Del 3.7
Estelle BONGINI 8
Component characterization / USP
Test performed on the heavy sleepers:
Static test rail seat
force
FF
cBcr
n n
Static test centre
F
co
n
5 kN
max. 120 kN/min
Dynamic test rail seat
time
10s < t < 5min
Fatigue test 2 Mio LC Static test, centre
Tests protocols and results detailed in RIVAS Del 3.7
Estelle BONGINI 9
Components characterization / URP
COMPLEMENTARY LAB TESTS
Characterization of the dynamic stiffness of the different
fastening systems on a test bench with realistic loading (static pre-
load + dynamic load) – 1 sleeper equipped with DFC and
VANGUARD on a ballast bed.
Numerical simulations to assess the mitigation effect on the test site of these
systems: an IL up to 20dB can be reached with VANGUARD installation
Test bench
Dynamic stiffness estimation
Under realistic load
Insertion loss of the free field velocity at 32m for the DFC system (dashed line) and the
VANGUARD system (dotted line) when compared to the standard SNCF pads
Tests protocols and results detailed in RIVAS Del 3.4
Estelle BONGINI 10Components certification / URP Rail fastening systems to be used on commercial track and to be let for 2 years require a certificate of use, according to EN 13146 and EN 13481. Static and dynamic loading tests Static and dynamic stiffness of the fastening system Performed before and after fatigue tests Inclined load tests Resistance against canting of the rail, with an inclined load at 33° Tests protocols and results to be detailed in RIVAS Del 3.5 Estelle BONGINI 11
Components certification / URP Electric insulation tests Longitudinal resistance before and after cyclic loading tests Extreme weather conditions tests Cyclic loading / Fatigue tests DFC are certified for combination of pads corresponding to a global stiffness of 24kN/mm, for a commercial use period of 2 years. Tests protocols and results to be detailed in RIVAS Del 3.5 Estelle BONGINI 12
Tests at scale 1 related to track mitigation solutions implementation Estelle BONGINI 13
USP implementation
Insertion loss under cyclic loading
CEDEX TRACK BOX TESTS
CEDEX track box measurements have been carried out to assess the
performances over time of a set of USP + heavy sleeper
tests performed:
• After tamping and stabilization of the track, several quasi static passenger
and freight train pass-by have been simulated
• 12195 quasi static pass-by of freight train simulated, corresponding to 2Mo
axle loads
• Track receptances are measured
• Track quasi static behaviour is checked regularly during the tests: during the
load cycles, static tests have been performed to check the track behaviour
Tests protocols and results detailed in RIVAS Del 3.7
Estelle BONGINI 14USP implementation Insertion loss under cyclic loading CEDEX TRACK BOX TESTS Estelle BONGINI 15
USP implementation
Insertion loss under cyclic loading
CEDEX TRACK BOX TESTS
• Measurement device:
124 sensors are available in track box: sleeper geophones, rail accelerometers,
sublayer geophones, displacement gauge (for fatigue tests), + 2 geophones on the
foundations of the box
• Train parameters: the pass-by of 2 types of train are simulated
Passenger trains: load equal to 165kN per axle; Quasi-static loading: excitation
below 30Hz
Freight trains: load equal to 225kN/axle; quasi-static excitation below 20Hz
Frequency content mainly due to the geometric parameters of the train (axle/bogie
distances)
Estelle BONGINI 16USP implementation
Insertion loss under cyclic loading
CEDEX TRACK BOX TESTS
Simulation of train passage over a medium class track (i.e. with longitudinal track
defects)
Simulation of vertical irregularities according to the transfer function established
between the geometric irregularities and the corresponding dynamic load (with a
given track stiffness and damping), in the frequency domain.
1,E-04
1,E-05 Dynamic load time history
Single-sided PSD track irregularity (m2/(rad/m))
1,E-06
1,E-07
1,E-08
1,E-09
1,E-10
1,E-11
1,E-12
1,E-13
0,1 1 10 100
Wavenunber (rad/m)
ORE B176 low ORE B176 high psd_0_150
1 s dynamic load time history sample derived
from the adopted PSD
Adopted PSD versus ORE PSD’s functions
Estelle BONGINI 17USP implementation
Insertion loss under cyclic loading
CEDEX TRACK BOX TESTS RESULTS
Insertion loss at the middle of the embankment for TS3 system when
compared to TS2 system
IL PTQ Geo137 GPvsGS IL FTQ GeoE137 GPvsGs IL DFT GeoE137 GPvsGS
8 6 20
6 4 15
2
4
10
0
IL(dB)
5
IL(dB)
IL(dB)
2 -2
0
0 -4
-5
-6
-2
-8 -10
-4 0 1 2 -10 0 -15 0
10 10 10 10 10
1
10
2
10 10
1
10
2
f(Hz) f(Hz) f(Hz)
Passenger train quasi-static velocity Freight vehicle quasi-static velocity Freight vehicle dynamic velocity
insertion loss insertion loss insertion loss
Estelle BONGINI 18USP implementation
Insertion loss under cyclic loading
CEDEX TRACK BOX TESTS RESULTS
Track receptances obtained with a 112.5 kN static load applied to the rail
Com GSGP st225kN_B_10kN_Act32Hz AC0E Com GSGP 225kN_C_SHH AC0E
-7 -5
10 10
-8
10 -6
10
-9
10
-7
10
-10
10
Receptance (m/N)
Receptance (m/N)
-8
10
-11
10
-9
10
-12
10
-10
-13 TS3 System 10
10
TS2 System
TS3 System
-14 -11
10 10 TS2 System
-15
10 1 2 3 10
-12
10 10 10 10
1
10
2
10
3
f(Hz) f(Hz)
With a 10 kN dynamic peak load pulse (15.6 ms rising With a 8 kN dynamic peak load pulse (0.5 ms rising
time) generated with one servo-hydraulic cylinder. time) generated with light hammer (0.45 Kg).
Estelle BONGINI 19USP implementation / test rig installation The heavy sleepers equipped with different type of USP have been tested few days ago, on a test rig with dedicated measurement device (a specific loading system) presented in the next presentations presented by Rüdiger Garburg and Michael Mistler Estelle BONGINI 20
URP implementation / track installation TEST ZONE DESIGN: For the DFC: For the VANGUARD: Test site in the East of France, on a Freight corridor (Thionville – Longuyon) Estelle BONGINI 21
URP implementation / track installation
TEST ZONE DESIGN: TRANSITION ZONES
• Estimation of the track stiffness evolution
140
120
/mm)
100
Trackstiffness(kN
80
60
40
20
0 20 40 60 80 100 120
Abscissa on the track (m)
• Estimation of the rail-wheel interaction force at these transitions, to be compared
with the interaction force experienced along a track with non-critical vertical defects
Interaction force for a leading wheel - Passenger coach
Interaction force for a leading wheel - FRET wagon
4.8 300 24 300
3.6 260 18 260
Wheel-Rail interaction force on:
m)
m)
12 220
Interactionforce(kN)
/m
2.4 220
- perfect track with transition zones for the
Interactionforce(kN)
Trackstiffness(kN/m
rackstiffness(kN
6 180
1.2 180
track stiffness (left)
0 140
0 140
- same track with usual geometrical
T
-6 100
-1.2 100
defects (right)
-2.4 60
No emergence on the interaction force -12 60
-3.6
350 400 450 500 550 600
abscissa on the track (m)
650 700
20
750 due to the transition zones -18
0 500 1000
Abscissa on the track (m)
20
1500
Estelle BONGINI 22URP implementation / track installation TEST ZONE CONSTRUCTION • Dedicated sleepers will be installed during a track removal with DFC fastening system equipped with « reference » pads (equivalent global stiffness of the fastening system eq. to 90kN/mm) • Pads (under rail or under baseplate) will be changed to gradually decrease the stiffness of the global system down to 24kN/mm • This version at 24kN/mm will be let in the track over 2 years • VANGUARD system could be use on the same sleepers for few days installation, allowing a 6kN/mm stiffness of the fastening system to be tested Estelle BONGINI 23
URP implementation / track installation TESTS TO BE PERFORMED: for each DFC / VANGUARD configuration • Commercial Freight and regional trains traffic • Measurements on a reference site and the test site: – ground dynamic properties via SASW characterization – Track receptances – rail accelerations during pass-by – ground vibrations during pass-by @ 8m, 16m and perhaps 32m – Track deflexion to check track stability Estelle BONGINI 24
This afternoon…
• Presentations of:
– The measurement protocol for assessing the mitigation measure
efficiency
– the specific loading system for the test rig
– the design process for the heavy sleeper equipped with USP
– The optimization of track maintenance
– The definition of a reference track for GV issue
Estelle BONGINI 25Thank you for your attention. Visit our website wwww.rivas-project.eu Estelle BONGINI 26
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