GRECEAM - Grup de recerca en contaminació per emissió acústica i en Mecànica
http://hdl.handle.net/2117/24010
2024-03-28T20:54:02ZAplicación de la técnica de emisión acústica (EA) para auscultación en diversos tipos de materiales y estructuras
http://hdl.handle.net/2117/13449
Aplicación de la técnica de emisión acústica (EA) para auscultación en diversos tipos de materiales y estructuras
Martínez González, Eva; Gallego Molina, Antolino; Infantes Vázquez, Cristobal; Benavent Climent, Amadeo; Morillas Romero, Leandro; Martínez Jequier, José; Juanes, Javier; Valea Pérez, Ángel
2011-10-06T08:40:24ZMartínez González, EvaGallego Molina, AntolinoInfantes Vázquez, CristobalBenavent Climent, AmadeoMorillas Romero, LeandroMartínez Jequier, JoséJuanes, JavierValea Pérez, ÁngelAnalysis of fracture resistance of tool steels by means of acoustic emission
http://hdl.handle.net/2117/12017
Analysis of fracture resistance of tool steels by means of acoustic emission
Martínez González, Eva; Picas Anfruns, Ingrid; Casellas Padró, Daniel; Romeu Garbí, Jordi
The automotive manufacturers currently use advanced high-strength steels (AHSS) to produce lightweight vehicles with increased safety performance. While showing excellent strengthto-weight ratios, AHSS have several limitations due to the high loads required in cold forming and cutting processes, which lead to accelerated wear and premature fracture of tools. Thus, new tool materials with improved mechanical behavior ought to be developed with regard to the tool failure mechanisms. The aim of this work is to shed light on the fracture mechanisms acting in
tools (i.e. crack nucleation and propagation) applying the acoustic emission (AE) technique. Bending tests using two different tool steels were monitored in order to establish a relationship
between AE signals and fracture events.
2011-03-22T13:06:33ZMartínez González, EvaPicas Anfruns, IngridCasellas Padró, DanielRomeu Garbí, JordiThe automotive manufacturers currently use advanced high-strength steels (AHSS) to produce lightweight vehicles with increased safety performance. While showing excellent strengthto-weight ratios, AHSS have several limitations due to the high loads required in cold forming and cutting processes, which lead to accelerated wear and premature fracture of tools. Thus, new tool materials with improved mechanical behavior ought to be developed with regard to the tool failure mechanisms. The aim of this work is to shed light on the fracture mechanisms acting in
tools (i.e. crack nucleation and propagation) applying the acoustic emission (AE) technique. Bending tests using two different tool steels were monitored in order to establish a relationship
between AE signals and fracture events.Planes específicos para la reducción de la contaminación acústica de la ciudad de Terrassa
http://hdl.handle.net/2117/10834
Planes específicos para la reducción de la contaminación acústica de la ciudad de Terrassa
Jiménez Diaz, Santiago; Romeu Garbí, Jordi; Genesca Francitorra, Meritxell; Alsina Sánchez, Antoni
La Directiva 2002/49 sobre evaluación y gestión del ruido ambiental contempla la adopción de planes de acción, tomando como base los resultados de los mapas estratégicos del ruido, con vistas a prevenir y reducir el ruido ambiental. El mapa estratégico de ruido de la aglomeración de Terrassa, pone de manifiesto las zonas donde se superan los índices de ruido, en las cuales sería necesario elaborar planes específicos de actuación. En este trabajo se presentan las actuaciones propuestas y realizadas así como, los resultados y el coste/beneficio obtenidos.
2010-12-29T15:56:30ZJiménez Diaz, SantiagoRomeu Garbí, JordiGenesca Francitorra, MeritxellAlsina Sánchez, AntoniLa Directiva 2002/49 sobre evaluación y gestión del ruido ambiental contempla la adopción de planes de acción, tomando como base los resultados de los mapas estratégicos del ruido, con vistas a prevenir y reducir el ruido ambiental. El mapa estratégico de ruido de la aglomeración de Terrassa, pone de manifiesto las zonas donde se superan los índices de ruido, en las cuales sería necesario elaborar planes específicos de actuación. En este trabajo se presentan las actuaciones propuestas y realizadas así como, los resultados y el coste/beneficio obtenidos.Mapas estratégicos de ruido en Catalunya
http://hdl.handle.net/2117/10329
Mapas estratégicos de ruido en Catalunya
Jiménez Diaz, Santiago; Romeu Garbí, Jordi; Pàmies Gómez, Teresa; Majó Torrent, Maite
La Directiva 2002/49 sobre evaluación y gestión del ruido ambiental demanda en caso de aglomeraciones, una serie de datos que hay que comunicar a la Comisión, entre los que se encuentran: el número de personas cuyas viviendas están expuestas a cada rango de valores Lden y de Lnight en dBA. En este trabajo se presentan los criterios contemplados en la delimitación de las aglomeraciones en el interior del territorio de Catalunya, así como las metodologías utilizadas en la estimación de los niveles sonoros y de la población expuesta a los diferentes indicadores de ruido, así como, los resultados obtenidos.
2010-11-16T18:58:36ZJiménez Diaz, SantiagoRomeu Garbí, JordiPàmies Gómez, TeresaMajó Torrent, MaiteLa Directiva 2002/49 sobre evaluación y gestión del ruido ambiental demanda en caso de aglomeraciones, una serie de datos que hay que comunicar a la Comisión, entre los que se encuentran: el número de personas cuyas viviendas están expuestas a cada rango de valores Lden y de Lnight en dBA. En este trabajo se presentan los criterios contemplados en la delimitación de las aglomeraciones en el interior del territorio de Catalunya, así como las metodologías utilizadas en la estimación de los niveles sonoros y de la población expuesta a los diferentes indicadores de ruido, así como, los resultados obtenidos.CATdBTren project: a complete model for the assessment of vibration impact from new railway infrastructures
http://hdl.handle.net/2117/10317
CATdBTren project: a complete model for the assessment of vibration impact from new railway infrastructures
Alarcón Rovira, Gabriel; Palacios Higueras, José Ignacio; Romeu Garbí, Jordi; Balastegui Manso, Andreu; Arcos Villamarín, Robert; Sánchez Venegas, Ángel
The prediction of vibration impact remains as a complex challenge for designers of new railway infrastructures. Due to the large quantity of parameters involved in the generation, transmission and reception of the vibration waves, it would be necessary to develop a complete study for each potential receiver, which would include: source, soil and building characterization,
infrastructure vibration behaviour modelling and, finally, countermeasures influence prediction.
This process can turn out to be very costly in terms of both time and money. Therefore, it is usually done only for areas very likely to suffer high vibration levels or for high sensitive buildings (hospital, educational).
The CATdBTren project, which has been awarded with R&D funding from the Catalonia
Government, is aimed to develop a new prediction tool for evaluating the vibration impact from new railway infrastructures as well as to develop new types of fastening systems having high vibration isolation properties. That tool is intended to be user-friendly and to produce results with
average accuracy, so it still will be required detailed studies of problematic areas.
In this sense, the software will model the contact forces caused by high-speed, conventional and underground rolling stock. Moreover, it will model the infrastructure’s vibration transmission behaviour, ground vibration propagation, terrain-foundation coupling and building vibration
mechanism. The CATdBTren prediction tool will be also capable of estimating the influence of the rolling stock, rail and wheel roughness, fastening system, substructure, soil vibration propagation properties and building characteristics, all in the final vibration impact.
2010-11-16T15:31:16ZAlarcón Rovira, GabrielPalacios Higueras, José IgnacioRomeu Garbí, JordiBalastegui Manso, AndreuArcos Villamarín, RobertSánchez Venegas, ÁngelThe prediction of vibration impact remains as a complex challenge for designers of new railway infrastructures. Due to the large quantity of parameters involved in the generation, transmission and reception of the vibration waves, it would be necessary to develop a complete study for each potential receiver, which would include: source, soil and building characterization,
infrastructure vibration behaviour modelling and, finally, countermeasures influence prediction.
This process can turn out to be very costly in terms of both time and money. Therefore, it is usually done only for areas very likely to suffer high vibration levels or for high sensitive buildings (hospital, educational).
The CATdBTren project, which has been awarded with R&D funding from the Catalonia
Government, is aimed to develop a new prediction tool for evaluating the vibration impact from new railway infrastructures as well as to develop new types of fastening systems having high vibration isolation properties. That tool is intended to be user-friendly and to produce results with
average accuracy, so it still will be required detailed studies of problematic areas.
In this sense, the software will model the contact forces caused by high-speed, conventional and underground rolling stock. Moreover, it will model the infrastructure’s vibration transmission behaviour, ground vibration propagation, terrain-foundation coupling and building vibration
mechanism. The CATdBTren prediction tool will be also capable of estimating the influence of the rolling stock, rail and wheel roughness, fastening system, substructure, soil vibration propagation properties and building characteristics, all in the final vibration impact.Two step optimization of transducer locations in single input single output tonal global active noise control in enclosures
http://hdl.handle.net/2117/10176
Two step optimization of transducer locations in single input single output tonal global active noise control in enclosures
Palacios Higueras, José Ignacio; Romeu Garbí, Jordi; Balastegui Manso, Andreu
Global active control of sound can be achieved inside enclosures under low modal
acoustic fields. However, the performance of the system depends largely on the localization of the elements of the control system. For a purely acoustic active control system in which secondary acoustic sources (loudspeakers) and pressure transducers (microphones) as error sensors are used, several optimization strategies have been proposed.
These strategies usually rely on partial approximation to the problem, focusing on the
study of number and localization of secondary sources without considering error transducers, or selecting the best positions of secondary sources and error transducers of an initial set of candidate locations for these elements. The strategy presented here for tonal global active noise control of steady states comprises two steps; the first is rather common for this sort of problem and its goal is to find the best locations for secondary sources and their strengths by minimizing the potential energy of the enclosure. The second step is the localization of the error transducer, which ensures the results of the first step. It is analytically demonstrated that for a single input single output system, the optimum location of error transducers is at a null pressure point of the optimally attenuated
acoustic field. It is also shown that in a real case, the optimum position is that of a
minimum of the optimally attenuated acoustic field. Finally, a numerical validation of this principle is carried out in a parallelipedic enclosure.
2010-11-08T14:25:47ZPalacios Higueras, José IgnacioRomeu Garbí, JordiBalastegui Manso, AndreuGlobal active control of sound can be achieved inside enclosures under low modal
acoustic fields. However, the performance of the system depends largely on the localization of the elements of the control system. For a purely acoustic active control system in which secondary acoustic sources (loudspeakers) and pressure transducers (microphones) as error sensors are used, several optimization strategies have been proposed.
These strategies usually rely on partial approximation to the problem, focusing on the
study of number and localization of secondary sources without considering error transducers, or selecting the best positions of secondary sources and error transducers of an initial set of candidate locations for these elements. The strategy presented here for tonal global active noise control of steady states comprises two steps; the first is rather common for this sort of problem and its goal is to find the best locations for secondary sources and their strengths by minimizing the potential energy of the enclosure. The second step is the localization of the error transducer, which ensures the results of the first step. It is analytically demonstrated that for a single input single output system, the optimum location of error transducers is at a null pressure point of the optimally attenuated
acoustic field. It is also shown that in a real case, the optimum position is that of a
minimum of the optimally attenuated acoustic field. Finally, a numerical validation of this principle is carried out in a parallelipedic enclosure.Analysis of fracture resistance of tool steels by means of acoustic emission.
http://hdl.handle.net/2117/10045
Analysis of fracture resistance of tool steels by means of acoustic emission.
Martínez González, Eva; Picas Anfruns, Ingrid; Casellas Padró, Daniel; Romeu Garbí, Jordi
The usage of advanced high strength steels (AHSS) in structural automotive components has
been broadened in the past few years to satisfy the strict specifications of the automotive industry.
Besides showing excellent strength to weight rations, AHSS have several limitations due to the high loads required in cold forming and cutting tools, which decrease considerably the tooling performances. Therefore, these important forces of impact provoke unforeseen breakage of the dies. The aim of this research is to study the micromechanical behaviour and fracture mechanisms (nucleation and crack propagation) during fracture of tool steels using the acoustic emission (EA) technique. To do that, bending testing specimens of different tool steels were monitored in order to establish a relationship between AE signals and their mechanical behavior (carbide breakage, cracks emanating from them and crack propagation through the metallic matrix).
2010-10-28T10:43:27ZMartínez González, EvaPicas Anfruns, IngridCasellas Padró, DanielRomeu Garbí, JordiThe usage of advanced high strength steels (AHSS) in structural automotive components has
been broadened in the past few years to satisfy the strict specifications of the automotive industry.
Besides showing excellent strength to weight rations, AHSS have several limitations due to the high loads required in cold forming and cutting tools, which decrease considerably the tooling performances. Therefore, these important forces of impact provoke unforeseen breakage of the dies. The aim of this research is to study the micromechanical behaviour and fracture mechanisms (nucleation and crack propagation) during fracture of tool steels using the acoustic emission (EA) technique. To do that, bending testing specimens of different tool steels were monitored in order to establish a relationship between AE signals and their mechanical behavior (carbide breakage, cracks emanating from them and crack propagation through the metallic matrix).Análisis, diseño y construcción de un chasis autoportante de material composite
http://hdl.handle.net/2117/9526
Análisis, diseño y construcción de un chasis autoportante de material composite
Velázquez Ameijide, Juan; Llumà Fuentes, Jordi; Sánchez, C; Martínez González, Eva; Ruiz, Carlos
Esta ponencia presenta el análisis estructural de un chasis autoportante para
un vehículo monoplaza de bajo consumo, realizada en materiales compuestos.
Este estudio comprende el análisis de los modos propios de vibración y su incidencia en la rigidez del chasis y la carrocería del vehículo. Se parte de un modelo existente, se parametriza y simula. La validación de los resultados se realiza mediante los resultados se realiza mediante los datos obtenidos en las pruebas de laboratorio.
Los posibles materiales para utilizar en el nuevo chasis propuesto se caracterizan mediante ensayos mecánicos estándar a fin de parametrizarlos para los programas de simulación. El ajuste fino de los valores obtenidos se realiza mediante las pruebas de laboratorio de la carrocería del modelo
existente.
2010-10-07T10:46:01ZVelázquez Ameijide, JuanLlumà Fuentes, JordiSánchez, CMartínez González, EvaRuiz, CarlosEsta ponencia presenta el análisis estructural de un chasis autoportante para
un vehículo monoplaza de bajo consumo, realizada en materiales compuestos.
Este estudio comprende el análisis de los modos propios de vibración y su incidencia en la rigidez del chasis y la carrocería del vehículo. Se parte de un modelo existente, se parametriza y simula. La validación de los resultados se realiza mediante los resultados se realiza mediante los datos obtenidos en las pruebas de laboratorio.
Los posibles materiales para utilizar en el nuevo chasis propuesto se caracterizan mediante ensayos mecánicos estándar a fin de parametrizarlos para los programas de simulación. El ajuste fino de los valores obtenidos se realiza mediante las pruebas de laboratorio de la carrocería del modelo
existente.Integral curriculum on noise control in Spain: a cooperative task
http://hdl.handle.net/2117/9165
Integral curriculum on noise control in Spain: a cooperative task
Romeu Garbí, Jordi; Genesca Francitorra, Meritxell; Pàmies Gómez, Teresa
Since the European Directive on Environmental Noise 2002/49 came into effect requiring strategic agglomeration and infrastructure noise maps to be made, the demand on environmental Acoustics knowledge has been boosted in Spain. Currently several groups and companies are available to carry out noise surveys and pointing out the noise causes in different streets or areas of a city. However, a second stage is starting now: once the noise causes are identified, control noise techniques needs to be applied. This fact is supported
in the Spanish adaptation of this regulation known as Ley del Ruido (2003) that states that noise control techniques should be applied to minimize the acoustic emission of municipal work activities, municipal devices, infrastructures, road work…This means that a demand on noise control knowledge is arising. This knowledge is scarcely provided in the bachelor degrees currently available in Spain, but there are some master degrees focused in Acoustics. However, it is difficult to find an institution that can cover all the
topics needed for a complete Acoustics curriculum. This work analyses the feasibility of creating an integral curriculum in noise control involving different Spanish research groups in order to take benefit of the expertise of each one to cover the legal and industrial needs of Acoustics knowledge. In that way, the teaching effort would be optimized and the appropriate facilities would be available,
however funds would be necessary for the mobility of teachers and students.
2010-09-29T14:46:19ZRomeu Garbí, JordiGenesca Francitorra, MeritxellPàmies Gómez, TeresaSince the European Directive on Environmental Noise 2002/49 came into effect requiring strategic agglomeration and infrastructure noise maps to be made, the demand on environmental Acoustics knowledge has been boosted in Spain. Currently several groups and companies are available to carry out noise surveys and pointing out the noise causes in different streets or areas of a city. However, a second stage is starting now: once the noise causes are identified, control noise techniques needs to be applied. This fact is supported
in the Spanish adaptation of this regulation known as Ley del Ruido (2003) that states that noise control techniques should be applied to minimize the acoustic emission of municipal work activities, municipal devices, infrastructures, road work…This means that a demand on noise control knowledge is arising. This knowledge is scarcely provided in the bachelor degrees currently available in Spain, but there are some master degrees focused in Acoustics. However, it is difficult to find an institution that can cover all the
topics needed for a complete Acoustics curriculum. This work analyses the feasibility of creating an integral curriculum in noise control involving different Spanish research groups in order to take benefit of the expertise of each one to cover the legal and industrial needs of Acoustics knowledge. In that way, the teaching effort would be optimized and the appropriate facilities would be available,
however funds would be necessary for the mobility of teachers and students.A measurement method to discriminate aircraft fly-over noise
http://hdl.handle.net/2117/9137
A measurement method to discriminate aircraft fly-over noise
Genesca Francitorra, Meritxell; Romeu Garbí, Jordi; Pàmies Gómez, Teresa
Currently aircraft noise monitoring systems use a mesh of single microphones distributed around an airport to continuously sample the noise level. This fact requires a manual process of aircraft noise event detection and classification in order to distinguish aircraft events from the rest of noise events in the recording. In the present paper a 3-meter-long 12-microphone linear array is used to automatically obtain a background noise free aircraft noise recording. The beamforming process separates the noise impinging in the array from above (potential aircraft noise) and the noise impinging from below (urban noise and reflections), the results are enhanced by the use of a trigger condition on the difference between both. The theoretical results reveals that the background noise in the aircraft noise recording can be attenuated by about 8 dB if the microphone array is optimally placed. The experimental tests shows that even in non optimal
placements the array still provides better results than a single microphone if the threshold value in the trigger condition
is properly set.
2010-09-28T18:18:58ZGenesca Francitorra, MeritxellRomeu Garbí, JordiPàmies Gómez, TeresaCurrently aircraft noise monitoring systems use a mesh of single microphones distributed around an airport to continuously sample the noise level. This fact requires a manual process of aircraft noise event detection and classification in order to distinguish aircraft events from the rest of noise events in the recording. In the present paper a 3-meter-long 12-microphone linear array is used to automatically obtain a background noise free aircraft noise recording. The beamforming process separates the noise impinging in the array from above (potential aircraft noise) and the noise impinging from below (urban noise and reflections), the results are enhanced by the use of a trigger condition on the difference between both. The theoretical results reveals that the background noise in the aircraft noise recording can be attenuated by about 8 dB if the microphone array is optimally placed. The experimental tests shows that even in non optimal
placements the array still provides better results than a single microphone if the threshold value in the trigger condition
is properly set.