Application of New Front-end Electronics for Non-destructive Testing of Railroad Wheel Sets

For more than 6 years, the automated ultrasonic and eddy-current systems for the inspection of railroad wheel sets, developed by Fraunhofer IZFP and Fraunhofer TEG, have been field-hardened through daily operation at various maintenance facilities of the Deutsche Bahn (DB). The testing stations are equipped with IZFP’s multi-channel electronics, a modular PC integrated system operating inside 19” rack-mounted industrial computers. Special requirements for new installations of stationary systems (AURA) and underfloor testing stations (UFPE) called for the development of state-of-the-art miniaturized front-end ultrasonic and eddy-current test instrumentation. This innovation offers new dimensions for the concept and design of such systems, including features providing effortless maintenance of the inspection systems. Due to the small size of the electronic modules they can be placed in close proximity to the transducer assembly. High-speed networking techniques ensure the transfer of all the acquired digital ultrasonic and eddy-current data from the frontend modules to the workstation responsible for data acquisition and analysis. The new front-end technology is applied for the testing stations of the latest generation. One example is a system installed at the DB plant Krefeld, specifically designed for the ultrasonic testing of ICE train drive wheels. The transducer assembly for wheel rim and disk inspection includes hot-swap modules with integrated UT front-end modules adapted to inspect specific wheel disk configurations. A second example represents testing equipment operating at the Süddeutsche Rail Service GmbH, Kaiserslautern. Ultrasonic and eddy-current front-end modules are responsible for the inspection of the wheel rim of disassembled wheel sets of freight cars. In addition to the wheel rim the solid axle is inspected in the same test stand using GE’s Phased Array system. Miniaturized front-end modules are also advantageous for the inspection with the wheel sets installed at the train. The concept of such an underfloor testing system is outlined.