Skip to main content
geoend-eiffel-web-12lts logogeoend-eiffel-web-12lts logo

The CODA Acquisition rack

The system called "CODA Rack" is a measurement equipment that allows the acquisition of multichannel ultrasonic data.
This system was designed through the ANR projects SENSO, ANR EVADEOS, RFI PdL 2IDANL, and evolved during the PIA-RSNR project ENDE.

Typical Applications

  • Detection of micro-cracks and closed cracks in concrete,
  • Temporal monitoring of stresses,
  • Monitoring of gradients in concrete properties.

Operating Principle

Emission

The Coda system is equipped with 2 arbitrary signal generators (~1V), associated with 2 voltage amplifiers to excite piezoelectric sensors (~200V). These sensors have the ability to deform depending on the electrical voltage applied to their terminals.

  • Coda Probe Section
    An emission of ultrasonic waves is performed around 500kHz (+/- 300kHz), using a high isolation relay matrix that allows selecting 1 to 16 sources.
     
  • Pump Section
    The second generator and its amplifier emit a wave with a lower frequency content (10kHz-50kHz), using high-energy sensors. This low-frequency and high-energy wave interacts with micro-cracks.
Reception

The system is capable of recording signals from 16 piezoelectric sensors (which generate a voltage when they deform), which are amplified and filtered for the 16 different wave paths from the source.

Processing

The signals from the 16 sensors (Coda probe section) are processed using methods based on coda wave interferometry (method NCWI, for Non-linear Coda Wave Interferometry). These measurements are sensitive to the presence of cracks due to the variation in speed measured at around 0.01%.

Hardware

To achieve these sensitivity levels, the hardware has high-end characteristics.

  • Arbitrary generation card – 2 16-bit 100MS/s PCI cards
  • CODA Amplifier 40kHz – 15 MHz - 400W
  • Pump Amplifier 100 VRMS 10Hz – 200kHz
  • Butterworth Analog Filter 2x8 channels High-Pass 100kHz
  • Pre-Amplifier – DC -1200kHz 20/40/60 dB
  • Acquisition Card - 2x8 channels 16 bits up to 25Ms/s PCIExpress.

The software MultiRecAveraging1 developed at the GéoEND laboratory, enables the monitoring of a structure by continuously measuring velocity variations and, at regular intervals, performing a set of measurements for imaging micro-cracks. Thanks to the reliability of the equipment and the robustness of the software, these measurements can last for several months.

The measurements can be uploaded to a university server, and the processing can be done remotely.

1 UNIV. G.EIFFEL IFSTTAR MULTI_ACQ 8/16 CHANNELS, VERSION TTL/Timed 3.6 08/03/2024, Olivier Durand

  • Chen, G., Abraham, O., Pageot, D., Durand, O., Chekroun, M., & Tournat, V. (2024). Evaluation of nonlinear interface areas in a multiple scattering medium by Nonlinear Coda Wave Interferometry (NCWI): Experimental studies. NDT & E International, 141, 102992. https://doi.org/10.1016/j.ndteint.2023.102992
  • Qu, S., Hilloulin, B., Saliba, J., Sbartai, M., Abraham, O., & Tournat, V. (2023). Imaging concrete cracks using Nonlinear Coda Wave Interferometry (INCWI). Construction and Building Materials, 391, 131772. https://doi.org/10.1016/j.conbuildmat.2023.131772
  • Thery, R., Guillemot, A., Abraham, O., & Larose, E. (2020). Tracking fluids in multiple scattering and highly porous materials: toward applications in non-destructive testing and seismic monitoring. Ultrasonics, 102, 106019. https://doi.org/10.1016/j.ultras.2019.106019
  • Chen, G., Abraham, O., Pageot, D., Durand, O., Chekroun, M., & Tournat, V. (2019). Monitoring Cracks with Nonlinear Coda Wave Interferometry (NCWI): Numerical and Experimental Results. Structural Health Monitoring 2019. http://dx.doi.org/10.12783/shm2019/32402
  • Legland J.-B., Zhang Y., Abraham O., Durand O., Tournat V., Evaluation of crack status in a meter-size concrete structure using the ultrasonic nonlinear coda wave interferometry, JASA, 142, 2233, 2017. https://doi.org/10.1121/1.5007832
  • Zhang Y., Tournat V. , Abraham O., Durand O., Letourneur S., Le Duff A. , Lascoup B. (2017). Nonlinear modulation of ultrasonic coda waves for the global evaluation of damage levels in complex solids, Ultrasonics, 73, pp245-252, 2017.https://doi.org/10.1016/j.ultras.2016.09.015
  • Hilloulin B., Legland J.-B., Lys E., Abraham O., Loukili A., Grondin F. , Durand D., Tournat V. (2016). Monitoring of autogenous crack healing in cementitious materials by the nonlinear modulation of ultrasonic coda waves, 3D microscopy and X-ray microtomography, JCBM, 123, pp143-152, 2016. https://doi.org/10.1016/j.conbuildmat.2016.06.138

Contacts