PSI - Issue 12

N. Bosso et al. / Procedia Structural Integrity 12 (2018) 344–352 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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4

Support

Support

Axle-Box tested 2

Axle-Box tested 2

Shaft

Lateral Actuator

Vertical Actuator

Belt

Motor

Fig. 1. Schematics of the R3 Test system developed by SKF.

Another test-bench was built by Schaeffler at the Industrial's Rail Test Facility in Schweinfurt, Germany, and allows testing up to 500 km/h, varying the lateral load and being able to simulate a contaminated environment, shown by Schaeffler (2013). Similar benches were built in China in relation to the bearing tests of the new high speed vehicles, as shown by Huang, et al. (2018). Some of these benches carry out the test using directly the assembled wheelset of the vehicle (DTR-W-30 test bench made by DanoblatGroup) or an entire bogie (DTR Dynamic train Bogie Test Rig, always made by DanoblatGroup). This type of benches can be conveniently used during periodic inspections of railway vehicles, possibly without having to dismount the vehicle. The test-rigs described above are normally used by bearing manufacturers to guarantee the performance of their products, or supplied to the user of the vehicle to facilitate maintenance activities. However, the development of new diagnostic systems requires test benches that can be used more flexibly to test new bearings or damaged bearings. Therefore, some universities and research centers have started to develop test benches to support their activities in the diagnostic field. These benches do not necessarily need to be able to perform damage tests, which require a large load capacity and durability of the bench components. Instead it is very important that the bench is equipped with control and data acquisition equipment capable of analyzing the dynamic response of the tested bearings. It is obvious that to calibrate a diagnostic algorithm, it is necessary to analyze a bearing at different wear levels and with different types of damage, but it is not essential that such damage has been produced with the bench itself. In fact, it is possible to opt for tests with already damaged bearings, the damage of which has been artificially realized or in any case has been previously identified. A test bench of this type is used at the University of Birmingham to identify bearing defects with different techniques, as shown by Amini, et al. (2016). Another axle-bearing test is currently being built at the University of Southampton in collaboration with the Perpetuum Company Ltd. within the "WARNTRAK - Horizon 2020" project. This test will be used to develop innovative monitoring systems, Corni, et al. (2018).

3. Design of test rigs for axle-box testing at Politecnico di Torino

At Politecnico di Torino, several test benches were designed to support the development of vehicle monitoring systems. The developed monitoring systems are based on an instrumented axle-box cover, made in different variants to adapt to different types of railway axle-boxes. In addition to the axle-box cover, the system consists of a monitoring board that can be installed in the vehicle frame or on the bogie frame and which includes additional sensors and the acquisition and processing system for the detected signals.