Articles de revista
http://hdl.handle.net/2117/3363
2021-02-26T02:44:04Z
2021-02-26T02:44:04Z
Investigation on electromagnetic vibration energy harvesting in water distribution control valves
Ordóñez Izquierdo, Víctor Hugo
Arcos Villamarín, Robert
Romeu Garbí, Jordi
Josefsson, Andreas
http://hdl.handle.net/2117/340517
2021-02-25T13:14:56Z
2021-02-25T12:43:15Z
Investigation on electromagnetic vibration energy harvesting in water distribution control valves
Ordóñez Izquierdo, Víctor Hugo; Arcos Villamarín, Robert; Romeu Garbí, Jordi; Josefsson, Andreas
Control stations of a water distribution system monitor several variables such as the pressure, the flow, and the quality of water. For these monitoring tasks, wireless sensor networks with ultra-low power consumption powered by vibration-based energy harvesters as an alternative to the usage of batteries or wired connections might be a suitable option in these facilities. This article investigates the potential applicability of an electromagnetic vibration energy harvester prototype in different control valves of a water distribution system in the province of Barcelona by means of experimental measurements and numerical simulations. The low-amplitude vibration with random excitation is measured with piezoelectric accelerometers in three control valves under normal operating conditions to process each signal and determine the dominant frequency in the complete spectrum, which is found to be in the order of magnitude of kHz, and the dominant frequency in the range of 10 to 100 Hz, where commercial harvesters normally operate. Numerical simulations of the harvester prototype are conducted in all cases with the same materials, geometries, and coil parameters, generating a maximum RMS load voltage and output power when the harvester’s natural frequency matches the dominant frequencies of each vibration signal. The maximum output power estimated in these simulations is 1573.04 nW with a corresponding RMS load voltage of 53.6 mV and optimal load resistance of 1830 O .
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2021-02-25T12:43:15Z
Ordóñez Izquierdo, Víctor Hugo
Arcos Villamarín, Robert
Romeu Garbí, Jordi
Josefsson, Andreas
Control stations of a water distribution system monitor several variables such as the pressure, the flow, and the quality of water. For these monitoring tasks, wireless sensor networks with ultra-low power consumption powered by vibration-based energy harvesters as an alternative to the usage of batteries or wired connections might be a suitable option in these facilities. This article investigates the potential applicability of an electromagnetic vibration energy harvester prototype in different control valves of a water distribution system in the province of Barcelona by means of experimental measurements and numerical simulations. The low-amplitude vibration with random excitation is measured with piezoelectric accelerometers in three control valves under normal operating conditions to process each signal and determine the dominant frequency in the complete spectrum, which is found to be in the order of magnitude of kHz, and the dominant frequency in the range of 10 to 100 Hz, where commercial harvesters normally operate. Numerical simulations of the harvester prototype are conducted in all cases with the same materials, geometries, and coil parameters, generating a maximum RMS load voltage and output power when the harvester’s natural frequency matches the dominant frequencies of each vibration signal. The maximum output power estimated in these simulations is 1573.04 nW with a corresponding RMS load voltage of 53.6 mV and optimal load resistance of 1830 O .
Nonlinear impact of traction rod on the dynamics of a high-speed rail vehicle carbody
Bokaeian, Vahid
Rezvani, Mohammad A.
Arcos Villamarín, Robert
http://hdl.handle.net/2117/340154
2021-02-21T19:42:40Z
2021-02-19T10:03:13Z
Nonlinear impact of traction rod on the dynamics of a high-speed rail vehicle carbody
Bokaeian, Vahid; Rezvani, Mohammad A.; Arcos Villamarín, Robert
This paper focuses on the bogie-carbody nonlinear dynamic interaction of a Shinkansen high-speed rail vehicle. The Euler-Bernoulli beam model is used to simulate vertical elastic vibrations of the carbody. As a novelty, the traction rod that connects the bogie frame and the carbody is considered a nonlinear element. The equivalent linearization method is used to analyze the nonlinear vehicle system in the frequency domain. The analytical spectrum solution was compared with the measured data from the running test and the numerical solution in the time domain. When the dynamic interaction due to the carbody’s flexibility is considered as nonlinear rather than linear, the maximum amplitude of the bounce acceleration relevant to the first bending mode increases by 38.2 percent at a travel speed of 300 km/h. Ride comfort improvement can be achieved with the inclusion of the nonlinear interaction. It is also feasible to manipulate the vehicle’s ride comfort by altering its bogie-base
2021-02-19T10:03:13Z
Bokaeian, Vahid
Rezvani, Mohammad A.
Arcos Villamarín, Robert
This paper focuses on the bogie-carbody nonlinear dynamic interaction of a Shinkansen high-speed rail vehicle. The Euler-Bernoulli beam model is used to simulate vertical elastic vibrations of the carbody. As a novelty, the traction rod that connects the bogie frame and the carbody is considered a nonlinear element. The equivalent linearization method is used to analyze the nonlinear vehicle system in the frequency domain. The analytical spectrum solution was compared with the measured data from the running test and the numerical solution in the time domain. When the dynamic interaction due to the carbody’s flexibility is considered as nonlinear rather than linear, the maximum amplitude of the bounce acceleration relevant to the first bending mode increases by 38.2 percent at a travel speed of 300 km/h. Ride comfort improvement can be achieved with the inclusion of the nonlinear interaction. It is also feasible to manipulate the vehicle’s ride comfort by altering its bogie-base
Traffic noise assessment based on mobile measurements
Quintero Pérez, Guillermo
Balastegui Manso, Andreu
Romeu Garbí, Jordi
http://hdl.handle.net/2117/336704
2021-02-07T21:15:45Z
2021-02-02T13:05:11Z
Traffic noise assessment based on mobile measurements
Quintero Pérez, Guillermo; Balastegui Manso, Andreu; Romeu Garbí, Jordi
Continuous noise monitoring based on mobile systems could provide a quick feedback to assess the effect of policies implemented by authorities to mitigate noise pollution. The present research verifies that mobile measurements taken along a main street and aggregated in time and space can accurately estimate noise levels at static points. As a consequence, mobile sensors would be suitable to build, and continuously update, noise maps. Furthermore, the experiment computes the optimum aggregation distance of the mobile measurements. To perform the mobile noise measurements, a low-cost noise sensor with an integrated GPS was mounted on a bicycle. One hour worth of measurements was taken along a main avenue with the mobile receiver simultaneously to 6 static measurement points. For the mobile receiver, the LAeq was computed aggregating samples within a radius from 1 m to 100 m around the static measurement points. Then, the error between the aggregated LAeq of the mobile and the static receivers for the same time period was computed. It is observed that the RMSE and the measurement uncertainties decrease as the aggregation distance increases, having a minimum at an aggregation radius of 33 m and reaching a stabilization due to the constant traffic of the studied street.
2021-02-02T13:05:11Z
Quintero Pérez, Guillermo
Balastegui Manso, Andreu
Romeu Garbí, Jordi
Continuous noise monitoring based on mobile systems could provide a quick feedback to assess the effect of policies implemented by authorities to mitigate noise pollution. The present research verifies that mobile measurements taken along a main street and aggregated in time and space can accurately estimate noise levels at static points. As a consequence, mobile sensors would be suitable to build, and continuously update, noise maps. Furthermore, the experiment computes the optimum aggregation distance of the mobile measurements. To perform the mobile noise measurements, a low-cost noise sensor with an integrated GPS was mounted on a bicycle. One hour worth of measurements was taken along a main avenue with the mobile receiver simultaneously to 6 static measurement points. For the mobile receiver, the LAeq was computed aggregating samples within a radius from 1 m to 100 m around the static measurement points. Then, the error between the aggregated LAeq of the mobile and the static receivers for the same time period was computed. It is observed that the RMSE and the measurement uncertainties decrease as the aggregation distance increases, having a minimum at an aggregation radius of 33 m and reaching a stabilization due to the constant traffic of the studied street.
A methodology based on 2.5D FEM-BEM for the evaluation of the vibration energy flow radiated by underground railway infrastructures
Ghangale, Dhananjay
Arcos Villamarín, Robert
Clot Razquin, Arnau
Cayero Becerra, Julián Francisco
Romeu Garbí, Jordi
http://hdl.handle.net/2117/334884
2020-12-23T14:51:46Z
2020-12-23T14:44:48Z
A methodology based on 2.5D FEM-BEM for the evaluation of the vibration energy flow radiated by underground railway infrastructures
Ghangale, Dhananjay; Arcos Villamarín, Robert; Clot Razquin, Arnau; Cayero Becerra, Julián Francisco; Romeu Garbí, Jordi
In this paper, a comprehensive numerical approach for modelling track/tunnel/soil systems in the context of ground-borne railway-induced vibration problems considering a full-space model of the soil is proposed. All the approach is formulated in the wavenumber-frequency domain and it consists of a coupled finite element–boundary element model of the tunnel/soil system, a semi-analytical model of the track, a multibody model for the vehicle and a model for the vibration propagation in the soil based on semi-analytical solutions of a cylindrical cavity in a full-space. This comprehensive approach has been developed with the aim of computing the vibration energy flow radiated upwards by underground railway tunnels. An axisymmetric formulation to deal with circular underground railway tunnels is included in the approach in order to improve the computational speed of the methodology. This formulation can also be used for other types of railway tunnels if a circular boundary of the boundary element mesh is considered. Since this methodology uses finite elements to model the tunnel structure, its modelling detail is higher than the previously developed methodologies dedicated to compute the vibration energy flow radiated by underground railway infrastructures, since they are based on semi-analytical modelling of the tunnel structure. The present methodology has been specifically designed to be used in general assessment studies about ground-borne underground railway-induced vibrations where decisions on the type of track and/or the application of mitigation measures at the source, as soft rail-pads, under-ballast or under-slab mats, have to be made. Moreover, this methodology can be used for the study of the vibration radiation patterns of railway tunnels.
2020-12-23T14:44:48Z
Ghangale, Dhananjay
Arcos Villamarín, Robert
Clot Razquin, Arnau
Cayero Becerra, Julián Francisco
Romeu Garbí, Jordi
In this paper, a comprehensive numerical approach for modelling track/tunnel/soil systems in the context of ground-borne railway-induced vibration problems considering a full-space model of the soil is proposed. All the approach is formulated in the wavenumber-frequency domain and it consists of a coupled finite element–boundary element model of the tunnel/soil system, a semi-analytical model of the track, a multibody model for the vehicle and a model for the vibration propagation in the soil based on semi-analytical solutions of a cylindrical cavity in a full-space. This comprehensive approach has been developed with the aim of computing the vibration energy flow radiated upwards by underground railway tunnels. An axisymmetric formulation to deal with circular underground railway tunnels is included in the approach in order to improve the computational speed of the methodology. This formulation can also be used for other types of railway tunnels if a circular boundary of the boundary element mesh is considered. Since this methodology uses finite elements to model the tunnel structure, its modelling detail is higher than the previously developed methodologies dedicated to compute the vibration energy flow radiated by underground railway infrastructures, since they are based on semi-analytical modelling of the tunnel structure. The present methodology has been specifically designed to be used in general assessment studies about ground-borne underground railway-induced vibrations where decisions on the type of track and/or the application of mitigation measures at the source, as soft rail-pads, under-ballast or under-slab mats, have to be made. Moreover, this methodology can be used for the study of the vibration radiation patterns of railway tunnels.
An efficient experimental methodology for the assessment of the dynamic behaviour of resilient elements
Reina, Salvatore
Arcos Villamarín, Robert
Clot Razquin, Arnau
Romeu Garbí, Jordi
http://hdl.handle.net/2117/330099
2020-10-11T23:26:52Z
2020-10-09T11:07:25Z
An efficient experimental methodology for the assessment of the dynamic behaviour of resilient elements
Reina, Salvatore; Arcos Villamarín, Robert; Clot Razquin, Arnau; Romeu Garbí, Jordi
The assessment of the dynamic behaviour of resilient elements can be performed using the indirect method as described in the standard ISO 10846-3. This paper presents a methodology for control the error on the estimation of the frequency response functions (FRF) required for the application of the indirect method when sweep sine excitation is used. Based on a simulation process, this methodology allows for the design of the sweep sine excitation parameters, i.e., the sweep rate and the force amplitude, to control three types of errors associated to the experimentally obtained FRF in the presence of background noise: a general error of the FRF in a selected frequency range, and the errors associated to the amplitude and the frequency of the FRF resonance peak. The signal processing method used can be also tested with this methodology. The methodology has been tested in the characterisation of two different resilient elements: an elastomer and a coil spring. The simulated error estimations has been found to be in good agreement with the errors found in the measured FRF. Furthermore, it is found that for large signal-to-noise ratios, both sweep rate and force amplitude significantly affect the FRF estimation error, while, for small signal-to-noise ratios, only the force amplitude can control the error efficiently. The current methodology is specially interesting for laboratory test rigs highly used for the dynamic characterisation of resilient elements which are required to operate efficiently, since it can be used for minimising test times and providing quality assurance. Moreover, the application of this methodology would be specially relevant when characterisation is done in noisy environments
2020-10-09T11:07:25Z
Reina, Salvatore
Arcos Villamarín, Robert
Clot Razquin, Arnau
Romeu Garbí, Jordi
The assessment of the dynamic behaviour of resilient elements can be performed using the indirect method as described in the standard ISO 10846-3. This paper presents a methodology for control the error on the estimation of the frequency response functions (FRF) required for the application of the indirect method when sweep sine excitation is used. Based on a simulation process, this methodology allows for the design of the sweep sine excitation parameters, i.e., the sweep rate and the force amplitude, to control three types of errors associated to the experimentally obtained FRF in the presence of background noise: a general error of the FRF in a selected frequency range, and the errors associated to the amplitude and the frequency of the FRF resonance peak. The signal processing method used can be also tested with this methodology. The methodology has been tested in the characterisation of two different resilient elements: an elastomer and a coil spring. The simulated error estimations has been found to be in good agreement with the errors found in the measured FRF. Furthermore, it is found that for large signal-to-noise ratios, both sweep rate and force amplitude significantly affect the FRF estimation error, while, for small signal-to-noise ratios, only the force amplitude can control the error efficiently. The current methodology is specially interesting for laboratory test rigs highly used for the dynamic characterisation of resilient elements which are required to operate efficiently, since it can be used for minimising test times and providing quality assurance. Moreover, the application of this methodology would be specially relevant when characterisation is done in noisy environments
A numerical and scaled experimental study on ride comfort enhancement of a high-speed rail vehicle through optimizing traction rod stiffness
Bokaeian, Vahid
Rezvani, Mohammad A.
Arcos Villamarín, Robert
http://hdl.handle.net/2117/329547
2021-01-01T01:43:21Z
2020-09-30T11:08:18Z
A numerical and scaled experimental study on ride comfort enhancement of a high-speed rail vehicle through optimizing traction rod stiffness
Bokaeian, Vahid; Rezvani, Mohammad A.; Arcos Villamarín, Robert
In this research, the effect of rail vehicle carbody’s flexural modes on the ride comfort of an example high-speed railway vehicle is investigated. The vehicle is modeled as a rigid multi-body system, where the rigid body vertical, longitudinal, pitch, and roll degrees of freedom of the carbody and bogie frames and the rigid body vertical and roll degrees of freedom of the wheelsets are considered. An Euler–Bernoulli beam theory is used to account for the flexural motion of the carbody. The longitudinal interaction between carbody and bogie through the traction rod is modeled as a nonlinear spring element. The corresponding equations of motion of the system in the frequency domain are obtained by using the equivalent linearization method. The effect of the traction rod is explored by using this model. Also, the optimal stiffness of the traction rod element that minimizes the flexural vibrations of the carbody is obtained through a genetic algorithm. With the optimal stiffness for the traction rod, the ride quality index at the center of the carbody floor is improved by 41% at a speed of 300 km/h. For the validation of numerical results, a scaled model of the vehicle with a scale factor of 24.5 was constructed, and its associated results are presented. The model was excited by random input signals, which were generated based on the power spectral density of the track irregularity function. The agreement between the simulation results and the scaled experimental outcome when compared with the measured data from other sources is found to be satisfactory. In the framework of the physical scaled model, the filtering effect due to the vehicle bogie base is also examined
2020-09-30T11:08:18Z
Bokaeian, Vahid
Rezvani, Mohammad A.
Arcos Villamarín, Robert
In this research, the effect of rail vehicle carbody’s flexural modes on the ride comfort of an example high-speed railway vehicle is investigated. The vehicle is modeled as a rigid multi-body system, where the rigid body vertical, longitudinal, pitch, and roll degrees of freedom of the carbody and bogie frames and the rigid body vertical and roll degrees of freedom of the wheelsets are considered. An Euler–Bernoulli beam theory is used to account for the flexural motion of the carbody. The longitudinal interaction between carbody and bogie through the traction rod is modeled as a nonlinear spring element. The corresponding equations of motion of the system in the frequency domain are obtained by using the equivalent linearization method. The effect of the traction rod is explored by using this model. Also, the optimal stiffness of the traction rod element that minimizes the flexural vibrations of the carbody is obtained through a genetic algorithm. With the optimal stiffness for the traction rod, the ride quality index at the center of the carbody floor is improved by 41% at a speed of 300 km/h. For the validation of numerical results, a scaled model of the vehicle with a scale factor of 24.5 was constructed, and its associated results are presented. The model was excited by random input signals, which were generated based on the power spectral density of the track irregularity function. The agreement between the simulation results and the scaled experimental outcome when compared with the measured data from other sources is found to be satisfactory. In the framework of the physical scaled model, the filtering effect due to the vehicle bogie base is also examined
Development of a hybrid FE-SEA-experimental model
Clot Razquin, Arnau
Meggitt, J.W.R.
Langley, Rob
Elliott, A
moorhouse, A
http://hdl.handle.net/2117/177691
2020-07-23T20:26:11Z
2020-02-13T16:08:36Z
Development of a hybrid FE-SEA-experimental model
Clot Razquin, Arnau; Meggitt, J.W.R.; Langley, Rob; Elliott, A; moorhouse, A
The vibro-acoustic response of complex structures with uncertain properties is a problem of great concern for modern industries. In recent years, much research has been devoted to the prediction of this response in the mid-frequency range where, because neither finite element analysis nor statistical energy analysis are appropriate, a hybrid deterministic-statistical approach becomes a suitable solution. Despite its potential, the existence of systems with active components that are too complex to be modelled numerically can limit the application of the method. However, it may still be possible to measure the dynamical response of these structures experimentally. This paper is hence concerned with the possibility of integrating experimental data into a hybrid deterministic-statistical method. To explain the new methodology, two similar case studies, consisting of a deterministic source structure that is coupled to a statistical plate receiver using passive isolators, are used. For each case, the vibratory excitation, characterised using in-situ blocked force measurements, the source structure mobility, and the isolators stiffness are experimentally determined and inserted in the proposed hybrid model of the system. The paper explains the techniques used for obtaining the considered experimental data and the theoretical model proposed for describing the systems. To validate the proposed approach, the predicted vibration response of the receiver plate is compared to the one obtained by experimentally randomising the plate in both case studies. The results show that a good agreement is obtained, both for the ensemble average response of the receiver structure and for the ensemble variance of this response. Moreover, the upper confidence bounds predicted by the hybrid method enclose well the ensemble of experimental results. The cause of some narrow-band differences observed between the predicted response and the experimental measurements is finally discussed. It is therefore concluded that the capabilities of the hybrid deterministic-statistical method can be clearly enhanced through the incorporation of experimental data prescribing active sub-systems
2020-02-13T16:08:36Z
Clot Razquin, Arnau
Meggitt, J.W.R.
Langley, Rob
Elliott, A
moorhouse, A
The vibro-acoustic response of complex structures with uncertain properties is a problem of great concern for modern industries. In recent years, much research has been devoted to the prediction of this response in the mid-frequency range where, because neither finite element analysis nor statistical energy analysis are appropriate, a hybrid deterministic-statistical approach becomes a suitable solution. Despite its potential, the existence of systems with active components that are too complex to be modelled numerically can limit the application of the method. However, it may still be possible to measure the dynamical response of these structures experimentally. This paper is hence concerned with the possibility of integrating experimental data into a hybrid deterministic-statistical method. To explain the new methodology, two similar case studies, consisting of a deterministic source structure that is coupled to a statistical plate receiver using passive isolators, are used. For each case, the vibratory excitation, characterised using in-situ blocked force measurements, the source structure mobility, and the isolators stiffness are experimentally determined and inserted in the proposed hybrid model of the system. The paper explains the techniques used for obtaining the considered experimental data and the theoretical model proposed for describing the systems. To validate the proposed approach, the predicted vibration response of the receiver plate is compared to the one obtained by experimentally randomising the plate in both case studies. The results show that a good agreement is obtained, both for the ensemble average response of the receiver structure and for the ensemble variance of this response. Moreover, the upper confidence bounds predicted by the hybrid method enclose well the ensemble of experimental results. The cause of some narrow-band differences observed between the predicted response and the experimental measurements is finally discussed. It is therefore concluded that the capabilities of the hybrid deterministic-statistical method can be clearly enhanced through the incorporation of experimental data prescribing active sub-systems
Experimental and numerical assessment of local resonance phenomena in 3D-printed acoustic metamaterials
Roca Cazorla, David
Pàmies Gómez, Teresa
Cante Terán, Juan Carlos
Lloberas Valls, Oriol
Oliver Olivella, Xavier
http://hdl.handle.net/2117/174731
2021-02-01T01:28:00Z
2020-01-13T23:08:35Z
Experimental and numerical assessment of local resonance phenomena in 3D-printed acoustic metamaterials
Roca Cazorla, David; Pàmies Gómez, Teresa; Cante Terán, Juan Carlos; Lloberas Valls, Oriol; Oliver Olivella, Xavier
The so called Locally Resonant Acoustic Metamaterials (LRAM) are a new kind of artificially engineered materials capable of attenuating acoustic waves. As the name suggests, this phenomenon occurs in the vicinity of internal frequencies of the material structure, and can give rise to acoustic bandgaps. One possible way to achieve this is by considering periodic arrangements of a certain topology (unit cell), smaller in size than the characteristic wavelength. In this context, a computational model based on a homogenization framework has been developed from which one can obtain the aforementioned resonance frequencies for a given LRAM unit cell design in the sub-wavelength regime, which is suitable for low-frequency applications. Aiming at validating both the proposed numerical model and the local resonance phenomena responsible for the attenuation capabilities of such materials, a 3D-printed prototype consisting of a plate with a well selected LRAM unit cell design has been built and its acoustic response to normal incident waves in the range between 500 and 2000 Hz has been tested in an impedance tube. The results demonstrate the attenuating capabilities of the proposed design in the targeted frequency range for normal incident sound pressure waves and also establish the proposed formulation as the fundamental base for the computational design of 3D-printed LRAM-based structures.
2020-01-13T23:08:35Z
Roca Cazorla, David
Pàmies Gómez, Teresa
Cante Terán, Juan Carlos
Lloberas Valls, Oriol
Oliver Olivella, Xavier
The so called Locally Resonant Acoustic Metamaterials (LRAM) are a new kind of artificially engineered materials capable of attenuating acoustic waves. As the name suggests, this phenomenon occurs in the vicinity of internal frequencies of the material structure, and can give rise to acoustic bandgaps. One possible way to achieve this is by considering periodic arrangements of a certain topology (unit cell), smaller in size than the characteristic wavelength. In this context, a computational model based on a homogenization framework has been developed from which one can obtain the aforementioned resonance frequencies for a given LRAM unit cell design in the sub-wavelength regime, which is suitable for low-frequency applications. Aiming at validating both the proposed numerical model and the local resonance phenomena responsible for the attenuation capabilities of such materials, a 3D-printed prototype consisting of a plate with a well selected LRAM unit cell design has been built and its acoustic response to normal incident waves in the range between 500 and 2000 Hz has been tested in an impedance tube. The results demonstrate the attenuating capabilities of the proposed design in the targeted frequency range for normal incident sound pressure waves and also establish the proposed formulation as the fundamental base for the computational design of 3D-printed LRAM-based structures.
Control of ground-borne underground railway-induced vibration from double-deck tunnel infrastructures by means of dynamic vibration absorbers
Noori, Beshshad
Arcos Villamarín, Robert
Clot Razquin, Arnau
Romeu Garbí, Jordi
http://hdl.handle.net/2117/174712
2020-07-23T22:15:25Z
2020-01-13T14:24:23Z
Control of ground-borne underground railway-induced vibration from double-deck tunnel infrastructures by means of dynamic vibration absorbers
Noori, Beshshad; Arcos Villamarín, Robert; Clot Razquin, Arnau; Romeu Garbí, Jordi
The aim of this study is to investigate the efficiency of Dynamic Vibration Absorbers (DVAs) as a vibration abatement solution for railway-induced vibrations in the framework of a doubledeck circular railway tunnel infrastructure. A previously developed semi-analytical model of the track-tunnel-ground system is employed to calculate the energy flow resulting from a train pass-by. A methodology for the coupling of a set of longitudinal distributions of DVAs over a railway system is presented as a general approach, as well as its specific application for the case of the double-deck tunnel model. In the basis of this model, a Genetic Algorithm (GA) is used to obtain the optimal parameters of the DVAs to minimize the vibration energy flow radiated upwards by the tunnel. The parameters of the DVAs set to be optimized are the natural frequency, the viscous damping and their positions. The results show that the DVAs would be an effective countermeasure to address railway induced ground-borne vibration as the total energy flowradiated upwards fromthe tunnel can be reduced by an amount between 5.3 dB and 6.6 dB with optimized DVAs depending on the type of the soil and the train speed
2020-01-13T14:24:23Z
Noori, Beshshad
Arcos Villamarín, Robert
Clot Razquin, Arnau
Romeu Garbí, Jordi
The aim of this study is to investigate the efficiency of Dynamic Vibration Absorbers (DVAs) as a vibration abatement solution for railway-induced vibrations in the framework of a doubledeck circular railway tunnel infrastructure. A previously developed semi-analytical model of the track-tunnel-ground system is employed to calculate the energy flow resulting from a train pass-by. A methodology for the coupling of a set of longitudinal distributions of DVAs over a railway system is presented as a general approach, as well as its specific application for the case of the double-deck tunnel model. In the basis of this model, a Genetic Algorithm (GA) is used to obtain the optimal parameters of the DVAs to minimize the vibration energy flow radiated upwards by the tunnel. The parameters of the DVAs set to be optimized are the natural frequency, the viscous damping and their positions. The results show that the DVAs would be an effective countermeasure to address railway induced ground-borne vibration as the total energy flowradiated upwards fromthe tunnel can be reduced by an amount between 5.3 dB and 6.6 dB with optimized DVAs depending on the type of the soil and the train speed
A low-cost noise measurement device for noise mapping based on mobile sampling
Quintero Pérez, Guillermo
Balastegui Manso, Andreu
Romeu Garbí, Jordi
http://hdl.handle.net/2117/171697
2021-02-07T08:46:22Z
2019-11-05T12:25:38Z
A low-cost noise measurement device for noise mapping based on mobile sampling
Quintero Pérez, Guillermo; Balastegui Manso, Andreu; Romeu Garbí, Jordi
For the production of representative noise maps, a large amount of information is necessary, which includes, among others, on-site measurements of environmental noise. Thus, mobile sampling emerges as a possible solution for the enhancement of data acquisition. The present paper proposes a low-cost noise monitoring device, in order to take georeferenced mobile measurements at each 1/3 octave band (63¿Hz–10¿kHz). The implementation and accuracy tests of the equipment are presented. It is found, under laboratory and field tests, that the device measurement values are around 0.5¿dB of those obtained with a Class 1 sound level meter for and around 1¿dB for 1/3 octave band. Furthermore, a set of mobile measurements taken suggest that it is actually possible to perform the mobile sampling, which would improve the spatiotemporal granularity of noise measurements without compromising the accuracy, although certain requirements should be fulfilled to ensure representativeness
2019-11-05T12:25:38Z
Quintero Pérez, Guillermo
Balastegui Manso, Andreu
Romeu Garbí, Jordi
For the production of representative noise maps, a large amount of information is necessary, which includes, among others, on-site measurements of environmental noise. Thus, mobile sampling emerges as a possible solution for the enhancement of data acquisition. The present paper proposes a low-cost noise monitoring device, in order to take georeferenced mobile measurements at each 1/3 octave band (63¿Hz–10¿kHz). The implementation and accuracy tests of the equipment are presented. It is found, under laboratory and field tests, that the device measurement values are around 0.5¿dB of those obtained with a Class 1 sound level meter for and around 1¿dB for 1/3 octave band. Furthermore, a set of mobile measurements taken suggest that it is actually possible to perform the mobile sampling, which would improve the spatiotemporal granularity of noise measurements without compromising the accuracy, although certain requirements should be fulfilled to ensure representativeness