THE CASE OF USING A VEHICLE-TRACK INTERACTION PARAMETERS AND IMPACT TEST TO MONITOR OF THE TRAMWAY

Transcription

1 THE CASE OF USING A VEHICLE-TRACK INTERACTION PARAMETERS AND IMPACT TEST TO MONITOR OF THE TRAMWAY Bartosz Czechyra, Bartosz Firlik and Tomasz Nowakowski Poznan University of Technology, Institute of Combustion Engine and Transport, 3 PiotrowoStr. PL60-965Poznan, Poland bartosz.czechyra@put.poznan.pl In rail transportation systems the current knowledge about the technical parameters of the track is the key issue. Under normal operation very important role fully monitor the status of the track and make decision about repairs/modernization of the track. In the most cases management in this area based on carried out on the track geometric features. These information are important but not sufficient. It is necessary to take into account the dynamics of the track so the impact of the vehicle on the track and track to the vehicle. From this point of view, to carry out of complex studies in the vehicle-track interaction are beneficial for the vehicle operator and the owner of the infrastructure. The operator receives information about the impact of the track on the vehicle (vehicle wearing and quality of ride). At the same time owner of infrastructure has the ability to monitor the technical state of the track (wearing intensity, noise and vibration problem) and better manage of renewing their operating potential. The article presents the results of a comprehensive attempt to describe the dynamic properties of the tram track. The basis of experimental research was work carried out on the tram network of the City of Poznan (PL). There are introduced complex data from independent mobile system installed on the vehicle (MONIT), stationary monitoring system for control of tram vibroacoustic activity (T.ROLL) and data for impact test carried out on tram track as RFR characteristics. Based on these data, it is possible to create a map of the technical condition of the infrastructure taking into account the operating conditions of the tested tram network. 1. Introduction Technical state of track is basis to make decision about all form transportation process. It is the first component in case of speed limitation cause by safety criterion and risk management in rail public transport. Safety is the main reason why the tram and track cannot be analysed separately. Schema of interaction between track and tram in safety and ride comfort aspect is shown on Figure 1. ICSV22, Florence (Italy) July

2 Figure 1. Schema of track and tram interaction Assessment of the condition of the tram track is very difficult even within one network, because there are can be found many different track section and many different type of trams operated in the same time. Due to different dynamic conditions of the vehicle track interaction the most suitable tramway diagnostic system should base on tram response proportional to the excitation induced by track condition and driving conditions. Mobile system to diagnostics the technical condition of the track was developed and implemented in Poznan. The result of its work was compared with stationary system of tram vibroacoustic activity assessment and basic dynamic test of track. The first attempt to assess the sensitivity of the mobile system. 2. Mobile system MONIT The system (called MONIT) is based on a dispersed network of sensors installed on the vehicle along with the data acquisition unit and a data server with the application of analysis and management of diagnostic data. The monitoring process is realized on and from the vehicle, during its normal operation. The condition monitoring is based mainly on the acceleration signal analysis and all events are evaluated qualitatively. The general system architecture and complete monitoring system are presented in Figure 2. Figure 2. Condition monitoring system for light rail vehicle and track In case of the rail infrastructure, the system will allow: monitoring the main sections of infrastructure, increasing operational safety of the whole transportation system immediate detection of faults (cracks, weaken, flats, etc.) dynamic adjustment of speed limits depending on the current technical state of the given track section (including switches and crossings), life cycle costs assessment of the selected track section, including a history of events and trends of consumption. ICSV22, Florence, Italy, July

3 The modern approach is the use of smart sensor networks, which can not only collect data, but also perform distributed data processing and filter out unnecessary information before submitting it to system operator. Such distributed approach allows to increase the computing power across the network while optimizing the volume of data that is transferred between nodes. As the computations take place in sensor units it is also possible to simplify the design of data acquisition unit which would be responsible mostly for gathering data. More details can be fined at [1, 2, 3]. In experimental tests MONIT system was mounted on the vehicle which is typical for new generation tram based on idea five-module tram with 3 bogies. In this case, the youngest tram type in the fleet carrier Poznan was chosen. It is Solaris Tramino S105p. An appearance and basic data of tram are presented on Figure 3. Producer: SOLARIS (PL) Model: Tramino S105p Vehicle length: 31,69 m Vehicle width: 2,4 m Vehicle height: 3,64 m Vehicle kerb mass: kg Number of unites: 5 Number of axles: 6 Production years: Figure 3. Tram type Solaris Tramino S105p 3. Stationary system T.ROLL The same type of tram was chosen as a probe to observation of all vibroacoustic consequences of tram ride. T.ROLL System (quiet.rolling stock) deliver information about the global vibroacoustic impact of vehicle on environment. The measure is defined by the author as Vibroacoustic Activity of Tram [4, 5]. This term describes tram noise and vibration effects in a quantitative and qualitative way at environmental impact aspect and it takes into account areas as shown below: tram acoustic signature, dynamic wheel-rail interaction at the micro-geometry level, dynamic vehicle interaction with infrastructure paraseismic vibration, acoustic field visualization. In this case only paraseismic vibration signal was used to further analysis. The signal can be used as a monitoring base to assess of technical state of tramway infrastructure in selected point. Monitoring of vibration parameters allows the estimation of the tracks degradation intensity cause of used vehicle types and loading (passengers flow). T.Roll system was installed on two different type of track was considered. Firs one it was one section of Poznan Fast Tram (PST). It is e classic tramway based on tram rail type Ri59, wooden sleepers with K type fastening system and crushed stone as a ballast. Second one it was classic track too, located in Junikowo Tram Line (JLT). Mine differences are: rail type S49 applied, concrete sleepers with SB fastening system and crushed stone as a ballast. Additional different is that the ballast is piled quite high close to head of rail. Both type of tested track is showed on Figure 4. ICSV22, Florence, Italy, July

4 Figure 4. Tested track; PST (left) and JLT (right) Nevertheless the JLT track is younger than PST more than 10 years (without modernization) technical state of both tracks is descripted by tram operator as a good. For the tests signals from trams type Solaris Tramino S105p were taken into account. 4. Track impact test Impact test was done for comparing the Frequency Response Function (FRF) of tested tracks. The characteristics helped assess the way of energy distribution in measured frequency band. Schema of measurement chain and photo from exemplary location is presented of Figure Recording module type B&K Rail, 2. Impact Hamer type B&K 8210, 3. Accelerometer type B&K 8344 Figure 5. Schema of measurement chain in impact test Force as a excitation was introduce into the track structure by impact placed in the base section sleeper. Distance between rail head and seismic accelerometer was fixed as a 1meter on both tracks. Averaging procedure as a base of FRF estimation was done on more than 40 repetition with a large range of forces. Obtained material was compared with the spectral characteristics of acceleration signals introduced by ride od tram. ICSV22, Florence, Italy, July

5 5. Results Research carried out using mobile system enabled to demonstrate the differences in the levels of vibration recorded on different tracks from point of view the tram. Excitation level in Y and Z direction is typical for tramway technology and can be descripted as geometrical summation of vibration from wheel (global vibration), measured as close as possible. The result of global vibration is shown on Figure 6 for both tested tracks. Figure 6. Global vibration for tested tracks As is apparent from Figure 6 the level of excitation of tram structure is different despite the test was done with a very similar velocity profile. In the remainder of research have been attempts to describe the structure of vibration recorded outside the track. New kind of test was provided on chosen slice of tested track. On the Figure 6 it is marked by bar close 30m from tram stop. At selected locations the vibration signals from the point of view of Infrastructure was recorded. For farther assessments signal from Z direction was chosen. Results of impact tests as a Inertance characteristic is presented on Figure 7 (left). Average spectrum of paraseismic acceleration for a constant speed (16.5m/s) on both tracks is shown on Figure 7 at right hand site. Figure 7. Inertance in Z direction (left) and spectrum of paraseismic acceleration (right) Presented characteristics indicate a completely different structure of the tested objects in the sense of answers to both excitation type. Recorded the paraseismic effects of tram ride are different than expected based on impact test results. May be due to FRF characteristics was averaged across ICSV22, Florence, Italy, July

6 a broad spectrum of excitations and the still unknown impact of repeatability and results averaging obtained during ride tests in a fixed tram speed. It is planned, that in further work the ride vibration comfort will be taken into account as an additional measure for the state of tram track description. All presented work is realized within the framework of a research Project - Innovative Urban Tram (WND-DEM-1-281/00), within the Demonstrator+ Programme of the National Centre for Research and Development, co-financed by the European Regional Development Fund under the Operational Programme Innovative Economy. REFERENCES 1 Czechyra, B., Firlik B., Condition monitoring system for a light rail vehicle, Proceedings 19 th International Congress on Sound and Vibration, Vilnius, Lithuania, July Firlik B., Czechyra B., Chudzikiewicz A., Condition Monitoring System for Light Rail Vehicle and Track, Key Engineering Materials Vol. 518 (2012) pp Czechyra B., Firlik B., Tomaszewski F.: Technical state monitoring method of light rail track wear Proceedings of the Fourth European Workshop on Structural Health Monitoring 2008, Edited by: UHL, OSTROWSKI, HOLNICKI-SZULC; DEStrech Publications, Inc., 439 North Duke Street Lancaster, Pennsylvania USA; page ; ISBN Czechyra B., Firlik B., Tomaszewski F., Monitoring System of the Tram Vibroacoustic Activity Level: General Concept, International Journal of Railway Technology, Civil- Comp Press 2014; ISSN Czechyra B., Noise and vibration activity of trams as a development of a tram acoustic signature, Proceedings 19th International Congress on Sound and Vibration, Vilnius, Lithuania, July ICSV22, Florence, Italy, July