french institute of science and technology for transport ... - Ifsttar

2_SCIENTIFIC AND TECHNICAL ACTIVITIES
Continuous health
report
Launched in 2008, the COMPOSI-GeC project aims to
develop composite materials whose core is instrumented
with fibre optic sensors.
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This instrumentation will produce a continuous diagnosis
of structural health. Amongst other things, this will allow
us to make better decisions about the appropriate time for
maintenance.
COMPOSI-GeC is part of the DECID2 project (Intelligent
Composite Material Demonstrator with a Dual Structural Health
Diagnosis Capacity) which is run by a consortium (1) that is
planning to build a demonstration rig for September 2012.
This will measure 20m x 3.5m and be made from composite
materials with dual instrumentation consisting of fibre optic
sensors and ultrasonic patches.
In order to foresee future research needs, the consortium will
build an open air ageing test rig at IFSTTAR’s Nantes site and
another demonstrator that is identical to the first.
One of the DECID2 project’s deliverables is a fibre optic sensor
with a smaller diameter (80μm) than most of those on the
market (125μm), which facilitates the monitoring of structures.
This fibre has been successfully inserted into long structural
shapes made from composite materials. The fatigue durability
of these materials has been tested at different temperatures
(1) The consortium consists of manufacturers - ETPO, DFC, IDIL, IX Fiber,
SYNERVIA, and laboratories - CETIM, Larmaur (Université de Rennes 1),
GEM (École Centrale de Nantes) and IFSTTAR.
(-60°C, ambient temperature and 60°C) and under dense UV
radiation (in collaboration with the NIST, Maryland, USA).
The goal is to evaluate the real structural capacities of intelligent
composite materials.
@ CONTACT
monssef.drissi-habti@ifsttar.fr
A specimen of instrumented composite
material with a fibre optic core
subjected to fatigue and flexural testing.
Specific test facility
developed by IFSTTAR
for the full-scale
fatigue testing of this
type of structure.
New railway tracks
without ballast
The FUI-NBT (New Ballastless Track project is backed
by the i-Trans competitiveness cluster and is an attempt
to develop a French design for rail track that is laid on
concrete slabs. The specifications for this include : usability
for freight at low speed and passengers at high
speed, a design life of 100 years, minimum maintenance
and a laying speed of 1km/day. The project has a budget
of €1.6M.
IFSTTAR is playing an active part in this project with its
industrial partners RAILTECH, ALSTOM, VOSSLOH and RFF,
initially for the design of the slabs. The project is currently at
the laboratory validation stage. For this, IFSTTAR has developed
a specific test facility for the full-scale fatigue testing of
this type of structure.
This novel facility makes it possible to apply cyclic mechanical
loading and thermal gradients simultaneously to the tested
slabs. The performance of this facility permit loading at 5Hz
with axle loads of up to 40 tonnes and maximum thermal
gradients in the concrete slabs of 0.8 °C/cm. The first results
correlate well with the models. Fatigue tests are to be
performed up to 10 million cycles in order to validate the last
phase of the project which consists of the construction of a
1km section on a real railway line in early 2013.
@ CONTACT
louis-marie.cottineau@ifsttar.fr,
jean-michel.piau@ifsttar.fr & thierry.sedran@ifsttar.fr
ifsttar French Institute of Science and Technology for Transport, Development and Networks