دانلود رایگان مقاله سیستم نظارت ساختاری زنجیره راه آهن بی سیم

Abstract

Full-scale structural measurements of new and existing railway catenary systems are becoming increasingly important due to continually increasing train speeds and the resulting consequences. Higher speeds lead to increased loads and greater structural dynamic responses, necessitating that both static and dynamic regulations be fulfilled. Sampling directly on railway catenary sections is necessary to assess their structural behaviour. The results can both be analysed directly and be used for validating and/or improving numerical models, which in turn can be used to explore the structural response at higher speeds. This case study presents and explores a newly developed wireless sensor system that includes multiple sensors that can be mounted arbitrarily on any of the wires in a catenary system. All sensors synchronously sample accelerations and rotational velocities over a range of up to 1400 m. This paper shows the results of mounting the developed sensor system and sampling the data of an existing railway catenary section at the Hovin station in Norway. Sampling was performed from both self-excited tests and 140 scheduled train passages. The outputs have been analysed to show that the data can be used to successfully assess railway catenary structural response components.

5. Conclusions

A new monitoring system was described and applied to an assessment of the dynamic behaviour of railway catenary systems. The investigation also provided possible analyses of sampled full-scale measurements using operational modal analysis.Arailway catenary section located atthe Hovin station in Norway was used as a case study for the monitoring system evaluation. The monitoring system was successfully mounted within a limited time; mounting all sensors took 5 min, which demonstrated the ability to mount the system rapidly in arbitrary locations. The system automatically sampled all train passages for a week—a total of 140 passages, which was more than sufficient to assess and demonstrate that the monitoring system was energy efficient. The results showed that the developed system was capable of monitoring relevant oscillations occurring in the catenary system regardless of the initiation source (e.g., wind, train). To ensure relevant sampling, the monitoring system could be controlled either manually through a wireless wide-area network or by appropriate trigger values. Finally, an operational modal analysis applied to the collected data showed that relevant information could be extracted and dynamic properties could be identified based on the sampled data, thus making it possible to use the modal results in a numerical model updating procedure.