The application of Operational Modal Analysis (OMA) in the railway sector opens a broad field...
CETEST offers a range of other on-track tests for the railway industry.
CETEST is accredited to perform noise tests in accordance with ISO 3095, ISO 3381, TSI 1304/2014, UIC 651, EN 15892, EN 15153 and UIC 644, amongst others.
CETEST has accumulated considerable worldwide expertise in all measurements related to noise and acoustics in railway projects.
State-of-the-art acoustics equipment (microphones, arrays, acquisition and post-processing software tools) enables CETEST to adapt to measurement requirements as specified in the corresponding international standards and provide advanced research capacities such as interior and exterior noise, warning devices, sound intensity, speech intelligibility.
At CETEST we measure and analyse vibration levels in components and subassemblies for compliance with standards and limits. For example, we calculate FRF (Frequency Response Function) to determine the vibration transmission between different components and suspension stages.
CETEST also performs order tracking, which is a useful tool in the detection of failures on rotating elements. Furthermore, we can analyse and compare the PSD (Power Spectral Density) against reference curves.
CETEST offers on-track and laboratory modal analysis testing. We perform Experimental Modal Analysis (EMA). This involves applying a known excitation to the component being studied by means of an instrumented hammer, shakers or through the relaxation method. This analysis is best-suited to elements of reduced dimensions or which present a low damping ratio.
We also perform Operational Modal Analysis (OMA), where the system is studied in normal operation conditions and it is assumed that the excitation received can be modelled as white noise. This analysis is recommended for elements of large dimensions in which the ambient excitation is constant in the frequency range being studied, such as railway bridges.
At CETEST, we help our clients analyse aerodynamic phenomena related to train performance.
CETEST is specialised in several types of aerodynamic tests: slipstream effect, head pressure pulse, maximum pressure variation in tunnels and resistance to motion, amongst others. These tests are performed in accordance with the stipulations of the standards EN14067-4, EN14067-5 and LOC & PAS TSI 2014.
Structural Health monitoring
CETEST is a specialist in extensometric on-track tests for determining stress levels in different components (bogies, car body frames or specific elements) during normal service.
CETEST measures the stress levels and determines the global stress history that the piece will experience during its operational life. This history is used to estimate the risk of fatigue failure by means of the cumulative damage method, also known as Miner’s rule. This calculation involves comparing the measured stress levels against an S-N curve (in compliance with standards EN 1999-1-3, EN 1993-1-9 and ERRI B12/RP60).
Traction, braking and current collection performance
CETEST is accredited to evaluate the traction performance (effort-speed characteristic curve) and traction chain functionality of rail vehicles in different running configurations according to TSI 1302/2014, EN 50215, EN 50163, EN 14067-4 and EN 50388.
Braking performance measurements involve speed, brake pad temperatures, air pressures, acceleration, brake activation and other parameters, in order to fully understand the vehicle’s braking behaviour under each test configuration. CETEST is accredited to perform braking performance evaluations according to standards UIC 544, TSI CR, TSI HS and TSI LOC & PAS.
CETEST is accredited to perform current collection quality tests according to EN 50317, EN 50367 and TSI. We evaluate the current collection quality through the following tests:
- Evaluation of the contact forces between the pantograph head and the catenary by an instrumented pantograph
- Wire uplift
- Measurement of arching