Detection de fissure sur structure en mer en presence de salissure marine projet "Crabe"

The "CRABE" method is a crack detection technique based on the use of low electromagnetic frequencies. This (patented) method relies on a global injection of current within the structure under inspection. The presence of a crack shall cause a disruption in the current flow, and consequently of the magnetic field off the surface in the vicinity of a defect. It is this magnetic signature which is detected by the magnetic sensor used with "CRABE". The major advantage of this process, developed by TRAVOCEAN and the LETI Division of CEA with the help of IFREMER, appears clearly: No preliminary cleaning of the welds to be inspected is required, since no contact is necessary. Similarly, it shall be possible to inspect the whole of structures to a total cost all the more reduced than the detection equipment can be operated by means of a ROV (Remotely Operated Vehicle).