Academic literature on the topic 'Rolling sounds'

Three listening tests were conducted to perceptually evaluate different versions of a new real-time synthesis approach for sounds of sustained contact interactions. This study aims to identify the most effective algorithm to create a realistic sound for rolling objects. In Experiment 1 and 2, participants were asked to rate the extent to which 6 different versions sounded like rolling sounds. Subsequently, in Experiment 3, participants compared the 6 versions best rated in Experiment 1 and 2, to the original recordings. Results are presented in terms of both statistical analysis of the most effective synthesis algorithm and qualitative user comments. On methodological grounds, the comparison of Experiments 1, 2 and 3 highlights major differences between judgments collected in reference to the original recordings as opposed to judgments based on memory representations of rolling sounds.

In this article, we propose a control strategy for synthesized continuous-interaction sounds. The framework of our research is based on the action–object paradigm that describes the sound as the result of an action on an object and that presumes the existence of sound invariants (i.e., perceptually relevant signal morphologies that carry information about the action's or the object's attributes). Auditory cues are investigated here for the evocations of rubbing, scratching, and rolling interactions. A generic sound-synthesis model that simulates these interactions is detailed. We then suggest an intuitive control strategy that enables users to navigate continuously from one interaction to another in an “action space,” thereby offering the possibility to simulate morphed interactions—for instance, ones that morph between rubbing and rolling.

It is believed that the human ear is very sensitive to subtle changes in sounds. In the context of a guitar, the myriad of sounds produced by the strings depends majorly on the plucking technique of the player, but it is hypothesized that the sound produced by a string is also influenced, to some degree, by the thickness of the plectrum used for playing. This has led many to speculate whether bands and artists like the Beatles, Led Zeppelin and the Rolling Stones would have sounded very different if they hadn't used the right guitar plectrum. In this research paper, three plectrums of different thickness have been used to pluck electric guitar strings and the output electric voltage has been documented using the software Visual Analyzer. The observations show that the thickness of a plectrum indeed influences the sound produced by a guitar string to a significant extent

This paper presents a new method in damage detection by taking the sound signals of the rolling bearings in different levels. The tested bearing was put on the end of the shaft rotated by permanent magnet synchronous motor. The sound signal produced by this rig was recorded separately for each bearing condition with the same experimental environment. The sound data signals are compared each other. Based on the cross-correlation analysis, the recorded sound signal proved that the signals were recorded with the same environment. The power spectra calculation has shown different harmonic frequencies according to various bearing conditions. The total power of the sound is decreased along with the increasing damage. This is also confirmed by the auto-correlation of each sound signal that shows the appearance of the sounds impulse repetition with a wider period.

Micro-mobility transportation, including electric scooters and e-bikes, could bring substantial benefits to resolving road congestion, provide an eco-friendly transportation system, offer low-cost personal transportation, and increase accessibility. Another benefit is that electric scooters are very quiet, only producing some minimal rolling noise and high frequency emission due to electric motors. Quietness of the vehicles has led to safety concerns being raised by accessibility groups, such as the Royal National Institute of Blind people (RNIB). For this reason, we have teamed up with the RNIB to explore, well-designed Acoustic Vehicle Alerting Systems (AVAS) as a potential solution to ensure vehicle detection and avoid potential conflict with pedestrians. This paper presents the key findings of a research project carried out by the University of Salford's Acoustic Research Centre, in collaboration with Dott Scooters and RNIB. The goal of this project was to develop a stand-alone warning sound system for electric scooters, with the main constraint of ensuring an appropriate balancing between vehicle awareness and noise annoyance. Based on preliminary results, this project concluded that a significant benefit, in terms of vehicle noticeability, is observed with the addition of a warning sound. Funding has been secured to carry out further research to optimise the AVAS for complex urban environments.

Rolling/sliding contacts, such as rolling-element bearings or gears, are a keystone of many machines, which could not properly operate in absence of these components. Machine elements of this kind are typically made of certain variants of steel, whereby hardening processes are carried out in order to increase lifetime and reduce wear. Furthermore, proper lubrication of these tribo-systems is inevitable in order to guarantee a safe operation throughout the component’s lifetime. In recent years high performance polymers, such as Polyether ether ketone (PEEK) or polyamid 46 (PA46), have become an option for application in rolling/sliding contacts. Due to the low density and effective manufacturing processes, such as injection moulding, polymers enable lightweight design solutions under relatively low cost. A comparative investigation based on tribological properties including the friction and wear behaviour of two polymers (Polyamide 6, Polytetrafluoroethylene) was researched in this study. Where samples were prepared by machining for precast cylinders of these materials, and experiments were carried out using a device designed for this purpose, with two parameters (rolling speeds and loads) in select. The morphology of the polymeric transfer film which plays a lubricating role in the dry operation conditions was observed for both materials. The obtained results showed that the friction feature of PTFE was better than that of PA 6 which released high sounds during testing duo to adhesion bonds with metallic counterface. The main wear mechanism of polyamide was micro mechanical machining and deformation, while was adhesive wear for PTFE, and the wear rate of PTFE was very high compared to PA 6 which suffered from delamination wear in some cases

To reduce noise exposure along railway lines various combinations of noise mitigation measures can be considered. However, predicting and assessing their effects is non-trivial and the potential need for multiple measures is difficult to communicate to stakeholders. Auralisation is a promising tool that can help to support communication and decision-making, and enable psychoacoustic evaluations. This paper presents developments of a physics-based auralisation model for train pass-bys that allows various mitigation measures to be included. The work is conducted within the European research project SILVARSTAR. The proposed model includes contribution from rolling noise, impact noise, traction, auxiliary systems, and aerodynamic noise. It is physically based and allows a direct assessment of pass-by parameters such as speed, roughness, wheel flats and track design. Based on the TWINS model, five structural transfer paths for rolling noise are considered to integrate mitigation measures such as wheel and rail dampers. Shielding by noise barriers is simulated with analytical models. Reflection at different ground types is considered and can account for track embankments. The results can be coupled to an immersive Virtual Reality environment, by first panning the synthesised sounds to a small virtual speaker array and subsequently dynamic binaural rendering for headphones.

When a child does not meet his or her developmental milestones within the predicted time or age, this is referred to as developmental delay. Developmental milestones are activities that certain children master or acquire at specific ages. Head balance, rolling, crawling, driving, and talking are a few examples. The mechanism of growth and the completion of such developmental milestones are referred to as child development. The patient was a 14 months old male child came to the hospital with complaint of inability to sit also he is unable to hold anything in his hand. As narrated by the mother the child was born to G2P1L1A1 mother at 9 months 5 days of gestation. The child has not yet attained gross motor milestone such as rolling over and no sit with support. The child attained immature pincer grasp at 12 months of age and has not attained mature pincer grasp. Social smile was attained at 6 months, stranger anxiety at 12 months and the child has not attained bye-bye. The child was alert to sounds by the age of 9 months .babbles at 10 months and says mama-dada at 12 months. The child is immunized till age. The marriage of the parents was non-consanguineous marriage. The child was born with a weight of 2.5 kg the mother had LSCS and breech delivery. The child did not cry immediately after birth. The child has history of fever after 3 months of delivery. The child is also interpreted as grade 1 mild malnutritious (71-80) %. Developmental delay and grade 1 mild malnutrition. The above study shows that Neck facilitation exercises in prone lying, Ice technique and proper brush technique for neck facilitation improves neck holding. Rolling facilitation in side lying position and proper handling positions helps in attaining milestones such as Rolling over. Facilitation of extension tone with vestibular rehabilitation helps to facilitate extensors. Family plays an important role in the management of such cases all the exercises should be properly explained to them for more improvement. Supporting the child while sitting, for example, might help him or her develop weight shifting, rotation, coordination, and balance.

Sensory as a vehicle of information is today a relevant topic. For many years, the immediacy and spontaneity of the visual approach has supported several theories affirming living in a real “eye culture”. Nowadays, these theories are overtaken, and architects and designers are more and more willing to enclose all the multisensory aspects in their projects. In this context, in Politecnico di Torino developed SounBe, an innovative-patented tool and method conceived in support to the selection of the most suitable materials within the possible hyper-choice, taking into consideration also the sound as a project requirement. Nevertheless, an effective validation of the efficacy of SounBe tool and method was still lacking. Therefore, the aim of the Doctorate research was to validate SounBe tool and method, verify its accuracy as a design tool as well as the effectiveness of the subjective tests performed following its method, and find out any possible improvement. A huge experimental phase was carried out in the anechoic chambers in Politecnico di Torino and IRCAM (Institut de Recherche et Coordination Acoustique/Musique) in Paris. The workspace was selected as testing ground because of the existing relationship between the acoustic conditions of the work environment and workers’ health, job satisfaction and wellbeing; office chair rolling sounds represented the main case-study of the experimentation. More than ninety subjects took part to different listening tests performed in ecologic, laboratory and SounBe conditions, comparing from time to time the results of the descriptive processes adopted to give a qualitative characterization to the sound. Subjective data were compared to objective measures, to better interpret the qualitative judgement. The key point of the validation was demonstrated: the comparability of sounds obtained with the SounBe method and from the real object in action, which was assumed as a reference, was proved. Moreover, a second objective of the research was looking for a possible implementation of the method. Therefore, a set of tests adopting the semantic differential technique were performed, disclosing the possibility to adopt also this technique to sounds obtained with SounBe tool. A final step of this Doctorate research consisted in a direct comparison with enterprises, in order to verify the potential interest of firms in investing on this innovative technology. In this context, the positive feedback as well as its acceptance by firms let hypothesize new activities to carry out after the Doctorate research. Some possible future steps could be finalized to the realization of a new working prototype, as well as the launch of a starting exploitation phase of the technology.

The goal with this project, was to explore the producing of a musicvideo with a synergistic focus in a practical way. Beside the practical work with the recording and editing of music and video, I wanted to explore the sound engineers role in such a project? To my help I had the video producer Hannes Knutsson from the small film- collective Lefvande Bilder and the singer, guitarist and songwriter Conny Flink. The result of my work is a musicvideo published on the internet website YouTube and the report of the making of it along with my work around the question above is published in this report. The name of the recorded and filmed song, written and performed by Conny Flink is ”My Way”.

[ES] El ruido de rodadura es un fenómeno producido debido a la interacción entre la rueda y el carril e inducido por las pequeñas irregularidades existentes en la superficie de ambos. Dichas irregularidades, conocidas como "rugosidad", provocan que se genere una vibración tanto en la rueda como el carril cuando el tren circula a una cierta velocidad, lo que consecuentemente lleva a la aparición de radiación acústica. Esto conforma una de las fuentes de molestias más relevantes y principal origen de la contaminación acústica producida por los trenes al circular por regiones urbanas densamente pobladas. Así, el objetivo de esta Tesis es el desarrollo de una metodología integral para la obtención de diseños de rueda viables mediante el uso de Algoritmos Genéticos (AG) con la finalidad de minimizar el ruido de rodadura asociado. Al desarrollar los mencionados algoritmos de optimización, el Método de Elementos Finitos (MEF) se combina con la parametrización geométrica de las diferentes tipologías de diseño de rueda analizadas, descritas en función de aquellos parámetros más relevantes para la presente investigación. Se hace uso de modelos linealizados en el dominio de la frecuencia, capaces de resolver la dinámica completa del sistema a partir de las correspondientes mallas de la sección transversal. La obtención de la potencia acústica radiada se lleva a cabo mediante el empleo de una formulación semi-analítica para el cálculo de la eficiencia acústica de la rueda y al uso de un Modelo de Fuentes Equivalentes (MFE) en el carril. El desarrollo teórico, además, es validado con el software comercial de referencia en el campo de investigación, TWINS, en el cual se basa. A lo largo de los procedimientos de optimización, se realiza un análisis de fatiga en cada diseño de rueda considerado con el fin de asegurar su viabilidad estructural, lo que actúa como una restricción de "pena de muerte" en el algoritmo. Además, se desarrolla un procedimiento de identificación modal que permite caracterizar los modos de vibración y clasificarlos según su número de diámetros y circunferencias nodales. Seguidamente, se exploran dos formulaciones diferentes de la función objetivo: una centrada en reducir directamente el ruido radiado, llamada LA;W -min; i otra centrada en disminuir el ruido de rodadura maximizando la media de las frecuencias naturales de los modos de vibración, conocida como NF-max. En la metodología LA;W -min, se minimiza la suma en energía del nivel de potencia acústica expresado en dB(A). Para el caso de NF-max, se desplazan las frecuencias naturales a regiones de frecuencia donde la amplitud de rugosidad es menor. Se consideran diversas aproximaciones: la inclusión de esquemas de perforación y la modificación de la forma de su sección transversal. Además, también se ha estudiado la influencia en el ruido de la variación de las propiedades geométricas del carril y viscoelásticas de la vía. Como resultado de esta Tesis se han conseguido diversos modelos más silenciosos de rueda ferroviaria, con reducciones en el ruido de rodadura de hasta 5 dB(A). Cuando se considera el sistema ferroviario completo,se siguen consiguiendo mejoras en la potencia acústica radiada con los diseños de rueda resultantes. Además, se analizan las correlaciones entre la maximización de las frecuencias naturales y la atenuación del nivel de potencia acústica, estableciendo NF-max como una metodología adecuada para los casos en que se priorice la eficiencia computacional. La sensibilidad del problema a los espacios de diseño seleccionados y la adecuación del uso de AG se estudian también con la obtención de Superficies de Respuesta. Adicionalmente, se han establecido relaciones entre la variación de los parámetros geométricos y la disminución en la radiación acústica asociada, así como se ha propuesto la reubicación de los modos de vibración a lo largo del espectro en frecuencia com
[CA] El soroll de rodament és un fenomen causat per la interacció entre la roda i el carril i induït per les xicotetes irregularitats presents a les seues superfícies. Aquestes irregularitats, conegudes amb el nom de "rugositat", provoquen que es genere una vibració tant a la roda com al carril en circular el tren a una certa velocitat, el que conseqüentment du a l'aparició de radiació acústica. Açò conforma una de les fonts de molèsties més rellevants i el principal origen de la contaminació acústica generada pels trens al seu pas per regions urbanes densament poblades. Així, l'objectiu d'aquesta Tesi és el desenvolupament d'una metodologia integral per a l'obtenció de dissenys de roda viables mitjançant l'ús d'Algoritmes Genètics (AG) amb la inalitat de minimitzar el soroll de rodament associat. Al desenvolupar els esmentats algoritmes d'optimització, el Mètode d'Elements Finits (MEF) es combina amb la parametrització geomètrica de les diferents tipologies de disseny de roda analitzades, descrites en funció d'aquells paràmetres més rellevants per a aquesta investigació. Es fa ús de models linealitzats en el domini de la freqüència, capaços de resoldre la dinàmica completa del sistema a partir les corresponents malles de secció transversal. La obtenció de la potència acústica radiada es du a terme mitjançant la utilització d'una formulació semi-analítica per al càlcul de l'eficiència acústica de la roda i l'ús d'un Model de Fonts Equivalents (MFE) amb el carril. El desenvolupament teòric s'ha validat amb el software comercial de referència al camp d'investigació, TWINS, en el qual es basa. Al llarg dels procediments d'optimització, es realitza una anàlisi de fatiga a cada disseny de roda considerat amb la finalitat d'assegurar la seua viabilitat estructural. S'ha desenvolupat un procediment d'identificació modal que permet caracteritzar els modes de vibració i classificar-los d'acord al seu número de diàmetres i circumferències nodals. També, s'exploren dos formulacions diferents de la funció objectiu: una centrada en reduir directament el soroll radiat, anomenada LA;W -min; i altra centrada en disminuir el soroll de rodament maximitzant la mitja de les freqüències naturals dels modes de vibració, coneguda com NF-max. D'aquesta manera, en la metodologia LA;W -min, es minimitza la suma en energia del nivell de potència acústica expressat en dB(A). Per al cas de NF-max, es desplacen les freqüències naturals a regions de freqüència on l'amplitud de rugositat és menor. Es consideren diverses aproximacions: la inclusió d'esquemes de perforació i la modificació de la forma de la seua secció transversal, establint el radi com un valor fixe en un cas i utilitzant-lo com un paràmetre d'optimització més en l'altre. A més a més, s'ha estudiat la influència en el soroll de la variació de les propietats geomètriques del carril i viscoelàstiques de la via. Com a resultat d'aquesta Tesi s'han aconseguit diversos models de roda ferroviària més silenciosos, amb reduccions en el soroll de rodament de fins a 5 dB(A). Quan es considera el sistema ferroviari complet amb tots els seus components, es segueixen aconseguint millores en la potencia acústica radiada amb els dissenys de roda resultants. A més a més, 'analitzen les correlacions entre la maximització de les freqüències naturals i l'atenuació del nivell de potencia acústica, establint NF-max com una metodologia adequada pels casos en que es prioritza l'eficiència computacional. La sensibilitat del problema als espais de disseny escollits i l'adequació de l'ús de AG s'estudia també mitjançant l'obtenció de Superfícies de Resposta (SRs) per als paràmetres geomètrics utilitzats. Addicionalment, s'han establert relacions entre la variació dels paràmetres geomètrics i la disminució en la radiació acústica associada, així com s'ha proposat la reubicació dels modes de vibració al voltant de
[EN] Rolling noise phenomenon is produced due to the wheel/track interaction and induced by the small unevenness present in their surfaces. Such unevenness, known as "roughness", causes that vibrations arise in both the wheel and track when the train passes by with a certain speed, that consequently leads to the appearance of acoustic radiation. This kind of noise is one of the most relevant sources of annoyance and the principal focus of the railway acoustic pollution produced by trains operating through highly populated urban regions. Thus, the main goal of the present Thesis is the development of a comprehensive methodology to achieve suitable railway wheel designs through the use of Genetic Algorithms (GAs) with the aim of minimizing the associated rolling noise. When developing the aforementioned optimization algorithms, the Finite Element Method (FEM) is combined with the geometric parametrization of the different wheel design typologies analysed, described as a function of those parameters most relevant for the current research. In order to describe the dynamic behaviour of each component involved in the wheel/track interaction, use is made of linearised models in the frequency domain capable of solving the whole coupled dynamic response from the corresponding cross-section meshes. Subsequent derivation of the radiated sound power from the dynamic information is carried out by applying a semi-analytical formulation that allows for the wheel acoustic efficiency computation, on one hand, and by making use of an Equivalent Sources Model (ESM) in the track, on the other hand. Besides, such theoretical development is validated with the reference commercial software in the field, TWINS, on which it is based. Throughout the optimization procedures, a fatigue analysis is performed on every wheel design considered to assure structural feasibility, that acts as a "death penalty" constraint in the algorithm. Furthermore, a modal identification procedure is developed, which allows to characterize modeshapes and to classify them according to their number of nodal diameters and circumferences. Then, two different formulations of the objective function are explored: one focused on directly reducing radiated noise, named LA;W-min; and another centred on decreasing rolling noise by maximizing the average natural frequency of the modeshapes, called NF-max. Hence, in the LA;W -min methodology, the sum in energy of the wheel Sound poWer Level (SWL) expressed in dB(A) is minimized. For the NF-max case, natural frequencies are shifted to frequency regions where the roughness amplitude content is lower. Different approaches are considered: the inclusion of perforation schemes in the wheel and the variation of its cross-sectional shape, setting the radius as a constant value in one case and using it as an optimization parameter in another. Moreover, the influence on the noise of changing the rail geometric and track viscoelastic properties is also studied. As a result of the present Thesis, several quieter models of railway wheels have been achieved, with rolling noise reductions of up to 5 dB(A). When the whole railway system with all the components is considered, improvements in the radiated sound power remain achieved with the resulting wheel designs. Besides, correlations between maximization of natural frequencies and SWL mitigation are analysed, establishing the NF-max as a suitable methodology for cases when computational efficiency is prioritized. The sensitivity of the problem to selected design domains and the suitability of the use of GAs are also studied with the obtention of Response Surfaces (RSs) for the geometric parameters used. Additionally, correlations are established between the variation of the geometric parameters and the decrease in the associated acoustic radiation, while the shifting of the modeshapes along the frequency domain is proposed as a physical mechanism responsible of the observed sound power decrease.
This thesis has been supported by the Agencia Estatal de Investigación and the European Regional Development Fund (projects TRA2013-45596-C2-1-R and TRA2017-84701-R).
Garcia Andrés, X. (2021). Development of innovative methodologies to reduce railway rolling noise through Genetic Algorithm-based shape optimization techniques [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/164194
TESIS

Nous étudions la commandabilité du système de contrôle décrivant le procédé de roulement, sans glissement ni pivotement, de deux variétés riemanniennes n-dimensionnelles, l'une sur l'autre. Ce modèle est étroitement associé aux concepts de développement et d'holonomie des variétés, et il se généralise au cas de deux variétés affines. Les contributions principales sont celles données dans quatre articles, attachés à la fin de la thèse.Le premier d'entre eux «Rolling manifolds and Controllability : the 3D case»traite le cas où les deux variétés sont 3-dimensionelles. Nous donnons alors, la liste des cas possibles pour lesquelles le système n'est pas commandable.Dans le deuxième papier «Rolling manifolds on space forms», l'une des deux variétés est supposée être de courbure constante. On peut alors réduire l'étude de commandabilité à l'étude du groupe d'holonomie d'une certaine connexion vectorielle et on démontre, par exemple, que si la variété à courbure constante est une sphère n-dimensionelle et si ce groupe de l'holonomie n'agit pas transitivement, alors l'autre variété est en fait isométrique à la sphère.Le troisième article «A Characterization of Isometries between Riemannian Manifolds by using Development along Geodesic Triangles» décrit, en utilisant le procédé de roulement (ou développement) le long des lacets, une version alternative du théorème de Cartan-Ambrose-Hicks, qui caractérise, entre autres, les isométries riemanniennes. Plus précisément, on prouve que si on part d'une certaine orientation initiale, et si on ne roule que le long des lacets basés au point initial (associé à cette orientation), alors les deux variétés sont isométriques si (et seulement si) les chemins tracés par le procédé de roulement sur l'autre variété, sont tous des lacets.Finalement, le quatrième article «Rolling Manifolds without Spinning» étudie le procédé de roulement et sa commandabilité dans le cas où l'on ne peut pas pivoter. On caractérise alors les structures de toutes les orbites possibles en termes des groupes d'holonomie des variétés en question. On montre aussi qu'il n'existe aucune structure de fibré principal sur l'espace d'état tel que la distribution associée à ce modèle devienne une distribution principale, ce qui est à comparer notamment aux résultats du deuxième article.Par ailleurs, dans la troisième partie de cette thèse, nous construisons soigneusement le modèle de roulement dans le cadre plus général des variétés affines, ainsi que dans celui des variétés riemanniennes de dimensiondifférente
We study the controllability of the control system describing the rolling motion, without slipping nor spinning, of two n-dimensional Riemannian manifolds, one against the other.This model is closely related to the concepts of development and holonomy of the manifolds, and it generalizes to the case of affine manifolds.The main contributions are those given in four articles attached to the the thesis.First of them "Rolling manifolds and Controllability: the 3D case"deal with the case where the two manifolds are 3-dimensional. We give the listof all the possible cases for which the system is not controllable.In the second paper "Rolling manifolds on space forms"one of the manifolds is assumed to have constant curvature.We can then reduce the study of controllability to the study of the holonomy groupof a certain vector bundle connection and we show, for example, thatif the manifold with the constant curvature is an n-sphere and ifthis holonomy group does not act transitively,then the other manifold is in fact isometric to the sphere.The third paper "A Characterization of Isometries between Riemannian Manifolds by using Development along Geodesic Triangles"describes, by using the rolling motion (or development) along the loops,an alternative version of the Cartan-Ambrose-Hicks Theorem,which characterizes, among others, the Riemannian isometries.More precisely, we prove that if one starts from a certain initial orientation,and if one only rolls along loops based at the initial point (associated to this orientation),then the two manifolds are isometric if (and only if) the pathstraced by the rolling motion on the other manifolds, are all loops.Finally, the fourth paper "Rolling Manifolds without Spinning"studies the rolling motion, and its controllability, when slipping is allowed.We characterize the structure of all the possible orbits in terms of the holonomy groupsof the manifolds in question. It is also shown that there does not exist anyprincipal bundle structure such that the related distribution becomes a principal distribution,a fact that is to be compared especially to the results of the second article.Furthermore, in the third chapter of the thesis, we construct carefully the rolling modelin the more general framework of affine manifolds, as well as that of Riemannian manifolds,of possibly different dimensions

Le roulement est un élément essentiel dans la conception des machines tournantes. À l'échelle industrielle, sa défaillance peut avoir de coûteuses conséquences. La maintenance prédictive sert à minimiser les coûts d'entretien et à prévenir de l'état de fatigue du composant mécanique. Dans ce cadre, nous proposons une étude de l'endommagement par fatigue de contact de roulement appliquée au cas des butées à billes. Cette étude se structure en deux axes : numérique et expérimental. Le premier consiste à établir une modélisation numérique tridimensionnelle dynamique du passage cyclique d'une bille sur une bande de roulement en présence d'un indent, en utilisant la méthode des éléments finis. L'estimation de l'évolution de la taille d'un défaut d'écaillage initié en surface en fonction des cycles de chargement est effectuée. Ces résultats sont en adéquation avec les essais en laboratoire effectués dans les mêmes conditions à l'aide d'un banc d'essais de fatigue dédié aux butées à billes. Le deuxième axe consiste à déterminer un indicateur vibratoire utilisant l'analyse modale et permettant d'estimer le niveau d'endommagement de la butée à billes in situ en présence d'indent. La technique développée dans ces travaux permet de suivre l'évolution des valeurs de l'amortissement modal en fonction des cycles de vie, évolution déterminée à partir des essais en modes statique et dynamique. Cette étude contribuera à l'estimation de la durée de vie résiduelle du composant mécanique après apparition d'un écaillage en surface, en utilisant la méthode des éléments finis et en prenant compte de l'état d'endommagement de la structure
The bearing is an essential element in the design of rotating machines. In an industrial context, bearing failure can have extremely costly consequences. Predictive maintenance minimizes the intervention costs and warns about the state of fatigue of the mechanical component. In this frame, we propose a study of the rolling contact fatigue damage applied to thrust ball bearings. This study is twofold: numerical and experimental. The first axis consists in establishing a dynamic three-dimensional numerical model of the cyclic shift of a ball on a running surface in the presence of an indent, using the finite element method. An estimation of the size evolution of a surface initiated spall depending on loading cycles is also performed. These results are consistent with laboratory tests executed in the same conditions using a fatigue test rig dedicated to ball bearings. The second axis consists in determining a vibratory indicator using modal analysis to estimate the on-line structural damage level of the ball bearing in the presence of an indent. The technique developed in this work enables monitoring the evolution of the modal damping values based on the life cycles determined from tests in static and dynamic modes. This study will contribute to estimate the residual life of the mechanical component after onset of a spall using the finite element method and accounting for the structural damage state

Nous étudions deux problèmes différents qui ont leur origine dans la théorie du contrôle géométrique. Le Problème I consiste à étendre le concept du groupe d'holonomie horizontale sur une variété affine. Plus précisément, nous considérons une variété connexe lisse de dimension finie M, une connexion affine ∇ avec le groupe d'holonomie H∇ et une distribution lisse ∆ complètement non intégrable. Dans un premier temps, nous définissons le groupe d'holonomie ∆-horizontale H∆∇ comme le sous-groupe de H∇ obtenu par le transport parallèle le long des lacets tangents à ∆. Nous donnons les propriétés élémentaires de H∆∇ et ensuite nous faisons une étude détaillée en utilisant le formalisme de roulement. Il est montré en particulier que H∆∇ est un groupe de Lie. Dans un second temps, nous avons étudié un exemple explicite où M est un groupe de Carnot libre d'ordre 2 avec m ≥ 2 générateurs, et ∇ est la connexion de Levi-Civita associé à une métrique riemannienne sur M. Nous avons montré dans ce cas particulier que H∆∇ est compact et strictement inclus dans H∇ dès que m≥3. Le Problème II étudie la modélisation du problème du solveur d'esquisse. Ce problème est une des étapes d'un logiciel de CFAO. Notre but est d'arriver à une modélisation mathématique bien fondée et systématique du problème du solveur d'esquisse. Il s'agira ensuite de comprendre la convergence de l'algorithme, d'en améliorer les résultats et d'en étendre les fonctionnalités. L'idée directrice de l'algorithme est de remplacer tout d'abord les points de l'espace des sphères par des déplacements (éléments du groupe) et puis d'utiliser une méthode de Newton sur les groupes de Lie ainsi obtenus. Dans cette thèse, nous avons classifié les groupes de déplacements possibles en utilisant la théorie des groupes de Lie. En particulier, nous avons distingué trois ensembles, chaque ensemble contenant un type d'objet: le premier est l'ensemble des points, noté Points , le deuxième est l'ensemble des droites, noté Droites, et le troisième est l'ensemble des cercles et des droites, que nous notons ∧. Pour chaque type d'objet nous avons étudié tous les groupes de déplacements possibles, selon les propriétés souhaitées. Nous proposons finalement d'utiliser les groupes de déplacements suivant: pour le déplacement des points, le groupe des translations, qui agit transitivement sur Points ; pour les droites, le groupe des translations et rotations, qui est de dimension 3 et agit transitivement (globalement mais pas localement) sur Droites ; sur les droites et cercles, le groupe des anti-translations, rotations et dilatations qui est de dimension 4 et agit transitivement (globalement mais pas localement) sur ∧
We study two problems arising from geometric control theory. The Problem I consists of extending the concept of horizontal holonomy group for affine manifolds. More precisely, we consider a smooth connected finite-dimensional manifold M, an affine connection ∇ with holonomy group H∇ and ∆ a smooth completely non integrable distribution. We define the ∆-horizontal holonomy group H∆∇ as the subgroup of H∇ obtained by ∇-parallel transporting frames only along loops tangent to ∆. We first set elementary properties of H∆∇ and show how to study it using the rolling formalism. In particular, it is shown that H∆∇ is a Lie group. Moreover, we study an explicit example where M is a free step-two homogeneous Carnot group with m≥2 generators, and ∇ is the Levi-Civita connection associated to a Riemannian metric on M, and show in this particular case that H∆∇ is compact and strictly included in H∇ as soon as m≥3. The Problem II is studying the modeling of the problem of solver sketch. This problem is one of the steps of a CAD/CAM software. Our goal is to achieve a well founded mathematical modeling and systematic the problem of solver sketch. The next step is to understand the convergence of the algorithm, to improve the results and to expand the functionality. The main idea of the algorithm is to replace first the points of the space of spheres by displacements (elements of the group) and then use a Newton's method on Lie groups obtained. In this thesis, we classified the possible displacements of the groups using the theory of Lie groups. In particular, we distinguished three sets, each set containing an object type: the first one is the set of points, denoted Points, the second is the set of lines, denoted Lines, and the third is the set of circles and lines, we note that ∧. For each type of object, we investigated all the possible movements of groups, depending on the desired properties. Finally, we propose to use the following displacement of groups for the displacement of points, the group of translations, which acts transitively on Lines ; for the lines, the group of translations and rotations, which is 3-dimensional and acts transitively (globally but not locally) on Lines ; on lines and circles, the group of anti-translations, rotations and dilations which has dimension 4 and acts transitively (globally but not locally) on ∧

Dans cette these, nous considerons le probleme de la planification de la production pour une classe d'entreprises de sous-traitance. Celles-ci peuvent avoir une clientele tres diversifiee, ce qui implique notamment une grande variete des produits fabriques. Nous nous interessons en particulier au cas d'une entreprise de siderurgie, dont l'activite est le laminage a froid de feuillards d'acier. Etant donnee la complexite d'un tel probleme, nous avons envisage une approche hierarchisee, apres avoir defini des niveaux d'agregation sur les produits et sur les equipements. L'une des principales preoccupations de telles entreprises est de pouvoir proposer aux clients des delais competitifs, tout en s'assurant que ceux-ci puissent etre respectes. Pour cela, nous avons developpe un systeme d'aide a la decision base sur trois niveaux. Le premier niveau sert de support pour gerer de maniere dynamique l'arrivee de nouvelles commandes sur un horizon long terme, tout en effectuant une planification au niveau de l'usine. A partir des resultats obtenus, un deuxieme niveau verifie la faisabilite du plan de production en tenant compte des capacites des ateliers. Pour ce niveau plusieurs modeles adaptes a la classe d'entreprises consideree sont presentes. Enfin, le niveau inferieur a pour but d'assurer la coherence entre le plan prevu et le deroulement reel dans le systeme de production, en agissant sur les lancements en fabrication. Pour ce dernier module, nous presentons une approche heuristique specifique au cas particulier etudie, en prenant en compte des contraintes fortes du processus de fabrication, et nous proposons une generalisation possible de la methode pour d'autres entreprises de sous-traitance.

Le dimensionnement en fatigue à grand nombre de cycles d'un contact roulant entre des éléments ayant subi un traitement thermochimique de cémentation s'avère rapidement complexe.D'une part le traitement de cémentation apporte une hétérogénéité de propriété dans les couches supérieures de la pièce qui dépend du protocole utilisé. D'autre part le chargement de contact roulant est un chargement complexe dont le mode de défaillance en fatigue s'initie en sous-couche.Afin de limiter le temps de la caractérisation des champs de propriétés en fatigue, l'utilisation des mesures d'auto-échauffement sous sollicitation cyclique ainsi que leur interprétation par un modèle probabiliste à deux échelles est proposé. Néanmoins de par l'hétérogénéité du matériau et de par la particularité du chargement il peut s'avérer délicat d'appliquer une telle méthode d'évaluation. ll est alors proposé d'explorer ces deux difficultés de manière séparé.Pour prendre en compte l'hétérogénéité matériaux, un protocole d'analyse de courbe d'auto-échauffement basé sur une variante d'un modèle probabiliste à deux échelles et sur les mesures de taux de carbone a été proposé. Les paramètres du modèle ont été identifiés sur une classe d'acier via des mesures d'auto-échauffement réalisées sur des éprouvettes représentatives de l'hétérogénéité du au traitement de cémentation. Enfin le modèle a été validé par comparaison avec des points de fatigue expérimentaux.En ce qui concerne le chargement de contact roulant, les difficultés pour réaliser une mesure d'auto-échauffement ont mené à effectuer une première campagne de mesure sur le cas intermédiaire du contact répété. A l'aide d'un modèle analytique simple, l'évolution du champ de température a pu être reliée à un terme source de chaleur moyen dont le lien avec les mécanismes de fatigue reste à démontrer. Finalement, des prototypes de machine de contact roulant dédiés aux mesures d'auto-échauffement ont été proposés. Les mesures réalisées sur ces dernières et leur interprétation laissent à penser qu'il sera possible d'identifier des propriétés de fatigue à partir de mesure d'auto-échauffement
The rolling contact fatigue prediction between two carburizing part quickly becomes complex.On one hand, the carburizing treatment give heterogeneous properties in surface layer depending on the treatment protocol. On the other hand, the rolling contact load is a complex load with a fatigue initiation in the sub-layer. To limit the duration of the field fatigue properties characterization, self-heating measurements under cycle load are used and their interpretation by a probabilistic two scales model is proposed. Nevertheless applying this fatigue evaluation method on heterogeneous material and for rolling contact load can be difficult. ln first approach those difficulties are split.To take into account the material heterogeneity, an analysis based on a variation of one probabilistic two scales model and on carbon rate measurement is proposed. Model parameters are identified on one steel class with self-heating measurement made on specimens representative of carburizing material heterogeneity. Finally the model is validated by comparison with experimental fatigue point.Making self-heating measurement for rolling contact load is complex. Consequently a first self-heating measurement campaign is made on the intermediary case of repeated contact. With a simple analytic model, the temperature field evolution can be linked to a mean heat source whose link with fatigue mechanism must be proven. Finally, rolling contact machine prototypes are proposed. Self-heating measurement made on those prototypes and their interpretation suggest that it will be possible to identify fatigue properties with self-heating measurement

The final chapter focuses on official and unofficial cultural diplomacy efforts that have been organized to celebrate the United States and Cuba restoring diplomatic relations. Spring 2016 included a visit to Cuba by Barack Obama and free concerts by Major Lazer and the Rolling Stones in Havana. The following month, the President’s Committee on the Arts and Humanities led a delegation to Havana with various federal agencies represented. Unofficial musical diplomacy initiatives continued as well, such as a trip with Musicians Across the Straits, a program that brought performers from St. Augustine, Florida to Havana for a residency at the Fábrica de Arte Cubano.

Elizalde's band got strict rules from the Savoy management about the style of its music, and the BBC, British Broadcasting Company, ended his broadcasts. Rollini went to the USA to hire more reed players for Elizalde and his brother Art was one of them. Special performances enhanced Elizalde's popularity, but by mid-1927 the Savoy ended his contract and making records had virtually stopped. No reason for Elizalde to stop paying his men. They worked on the soundtrack of an early sound movie with PolaNegri, which did not bring them much publicity. A tour through the country to Scotland was a half success only and the band was falling apart. The Rollinis returned to New York.

Arthur Hand had an orchestra of his own which was incorporated into Kirkeby's California Ramblers and which he would co-lead with Ed Kirkeby. In April 1922, Kirkeby arranged for the first of countless record dates for almost any label. The band did not have a bass player and Adrian Rollini decided to fill the gap and quickly learned to play the bass saxophone. In just a few months, he developed a new style of playing, both for the bass line and for solo work. His sound would identify the California Ramblers for years to come. The band was fully employed from its start and one of their engagements was as a replacement for Paul Whiteman's band at the Palais Royal. However, Kirkeby and Hand preferred to have their own place where their band would perform regularly. They found it North of the City of New York and called it the California Ramblers Inn.

I used to enjoy listening to the National Weather Service forecasts on my short-wave weather radio. An endlessly repeated taped message updated every few hours might be less than thrilling, but the voices of the half-dozen or so forecasters made it come alive. Each one had an identifiable style and intonation; it was easy to assign personalities, even faces, to them. Ten years ago the announcers were all men. There was the one I labeled the grand elder, with his pontifical voice and distinctive, rolling rhythms. When cost-cutting forced the station to move from Manhattan to the grounds of the Brookhaven National Laboratory, way out on Long Island, he disappeared from the airways. Perhaps the daily commute on the Long Island Expressway was too much for the old fellow. I am sure I wasn’t the only listener to mourn the loss of his avuncular cadences. Another announcer who appealed to me spoke fluently until he came to an American Indian place name such as Manasquan or Wanaque (both in New Jersey). Then he hesitated. I could imagine the look of terror in his eyes when he scanned the next line of the script, and there it was, a word with fearsome Q-sounds or daunting combinations of con-sonants and vowels. If I had had any way of getting in touch with him, I would have comforted him by explaining how lucky he was to be broadcasting in the New York–New Jersey metropolitan area. Up in northern Maine, the forecasters have to cope with names such as Caucomgomoc and Chemquasabamticook. Some announcers proclaimed their individuality with what seemed like deliberately odd pronunciations of common words. The most original was the fellow who figured out a new way to say “climate,” an achievement I would have thought was impossible. He did it by lengthening the separation between the two syllables and heavily stressing the second: “cly-matt.”Eventually, the Weather Service hired its first woman announcer, a welcome addition; she made her mark immediately by shortening the phrase “Here are the latest Central Park observations” to “Here is the latest Central Park.”

This chapter examines the real and imagined South in relationship to the Muscle Shoals music industry by addressing how cultural outsiders like Jerry Wexler perpetuated stereotypes that fed the Muscle Shoals mystique. Dissemination of the Muscle Shoals mystique occurred through news articles, 45 rpm labels, and recordings made by Jimmy Cliff, the Rolling Stones, and Traffic. The chapter provides a close reading of the cumulative events that led to Paul Simon's arrival in Muscle Shoals. Positioning the songs recorded in the Shoals during the 1960s and early 1970s within a larger cultural context that includes the history, formation, and promotion of regional identity reveals how Muscle Shoals came to represent, for many, the continuation of an imagined South manifested in sound.

This chapter suggests that building a stone wall offers a lesson in poetry. The experience of writing a poem embodies a joyful feeling: the words take your shape as you wander through creek beds of syllables, with your own life rolling over them. Stones, like words, are everywhere; the trick to building a dry stone wall is to find stones that fit perfectly into one another and form a structure that will not collapse under its own weight. Stone walls, despite being made of one of the heaviest objects on the planet, all have a lightness and delicacy in the way the stones touch and balance. The best poems—made of the lightest things on the planet (words)—demonstrate a sturdiness, with the words coupled so perfectly that one cannot be removed without the whole structure crumbling. Writing a poem requires balancing sound, humor, feeling, and thought to support one another.

Labelling of data is an expensive, labour-intensive, and time consuming process and, as such, results in vast quantities of data being unexploited when performing analysis through data mining. This chapter presents a new paradigm using robust multivariate statistical methods to encapsulate normal operational behaviour—not failure behaviour—to autonomously derive unsupervised classifier labels for previously collected data in a rapid, cost-effective manner. This enables traditional machine learning to take place on a much richer dataset. Two case studies are presented in the mechanical engineering domain, namely, a wind turbine gearbox and a rolling element bearing. A statistically sound and robust methodology is contributed, allowing for rapid labelling of data to enable traditional data mining techniques. Model development is detailed, along with a comparative evaluation of the metrics. Robust derivatives are presented and their superiority is shown. Example “R” code is given in the appendix, allowing readers to employ the techniques discussed. High levels of agreement between the derived statistical approaches and the underlying condition of the components can be found, showing the practical nature and benefit of this approach.

The massive open online course is a development in distance education. The existing online courses for primary and middle school students are based on several classic open educational resources like images, sounds, animations, but they could also be based on competence achieving web games. Writing web games for each discipline competence is a hard task, achievable only by programmers. Using frameworks we can offer teachers and other content editors the possibility of creating their own web games for the students. In this sense we designed and implemented two frameworks. One framework is based on a configurable dialog between two players. The dialog can be configured with mathematical expressions based on formulas, fields for questions with expected answers, loops for repetition in case of wrong answers, mark giving algorithms. The second framework is based on a configurable board and dice. The board has to be designed as an image with several ordered cells. On each cell we can configure events like: showing simple messages, asking questions, reading surprises. All events can be configured with actions like: moving backward of forward on the table stepping a certain number of cells, rolling the dice again. Both frameworks are using the HTML5 web technology and a simple communication server side logic. Dialog based games are suitable to disciplines which are have mathematical formulas like arithmetic, physics, chemistry. The board games are suitable to disciplines where concepts must be learned and actions must be performed. Thus, the games implemented with these frameworks represent a more attractive way to perform distance education for primary and middle school students.

The main goal of the present work lies in the identification of the railway track properties that influence acoustic radiation, as well as in the analysis of these properties for the reduction of sound levels. This is achieved through a dynamic model of the railway wheel and track that allows the study of rolling noise, produced as a result of wheel/rail interaction. The vibroacoustic calculation methodology consists of characterising the railway wheel and track, using finite element techniques and periodic structure theory [1,2], respectively. Subsequently, the response of the railway components, which is caused by the roughness present in the surface of the wheel and rail, is determined. Finally, after having the vibrational response of the railway elements, the sound power radiated by them is calculated using the acoustic model developed by D. J. Thompson et al. and implemented in TWINS software [3]. The influence of the track properties on the sound radiation is analysed through statistical techniques applied to the acoustic power results of different track configurations. To do this, the geometry of the rail profile is parameterised and simulations are carried out by modifying these parameters and the viscoelastic properties of the track components. From the results obtained, a number of guidelines are presented for the noise mitigation of the involved railway subcomponents. Between the worst and the best track design, there are differences of approximately 7.5 dB(A) in the radiation (considering the wheel, rail and sleeper noise), which means that an optimised track design can be found with an acoustic radiation 5.5 times lower than another design.

When agricultural machines are operated on pavements, the vibration and noise caused by the interaction between the tire lugs and the road surface are inevitable. In conventional studies, it is considered that the dynamic behavior of a rolling agricultural tire is influenced by the vibration characteristics of the tire. Resonance occurs when the lug excitation frequency of the tire, which is defined as the lug number multiplied by the number of revolutions of the tire, becomes equal to the natural frequency of the tire. In other words, the rolling tire shows large vibrations in the direction of the natural mode corresponding to the natural frequency of the tire. However, the vibration mode of the rolling tire in resonance state has not yet been clarified. In this study, it is confirmed that the dynamic behavior of the rolling tire can be evaluated by performing sound pressure measurements using closely located microphones to the tire. Further, the vibration mode in the resonance state is identified by performing simultaneous measurements of the sound pressure, and the vibration mode corresponds to the natural mode of the tire is confirmed as well.

Railway rolling noise is nowadays a major source of acoustic pollution in urban areas, with nearly up to 12 million people daily affected in Europe by this phenomenon [1]. Hence, the search for ways of decreasing such noise radiation has become a highly active and significant research field. Following this approach, a Genetic Algorithms-based shape optimization of the railway wheel [2] is developed with the aim of minimizing rolling noise. Different approaches are considered to address the problem, such as directly minimizing radiated Sound poWer Level (SWL) or using the maximization of the natural frequencies if computational efficiency is especially critical. A parametric Finite Element model is implemented for the wheel based on the most relevant geometric parameters in rolling noise radiation. For the acoustic calculation, the sound radiation models used in the TWINS software [3] are adopted, which also accounts for the whole dynamics of the wheel/rail system. Furthermore, for every candidate wheel proposed, a structural analysis is computed in order to check design feasibility in accordance with the corresponding standard [4]. In all cases, new geometries for the wheel cross section are achieved that reduce the radiated rolling noise. REFERENCES [1] WHO European Centre for Environment and Health, “Burden of disease from environmental noise”, WHO, Tech. Rep., 2011 [2] X. Garcia-Andrés, J. Gutiérrez-Gil, J. Martínez-Casas and F. D. Denia, “Wheel shape optimization approaches to reduce railway rolling noise”, Struct. Multidiscipl. Optim., Vol. 62, pp. 2555-2570, (2020). [3] D. J. Thompson, B. Hemsworth and N. Vincent, “Experimental validation of the TWINS prediction program for rolling noise, part 1: Description of the model and method”, J. Sound Vib., Vol. 193 (1), pp. 123–135, (1996). [4] UNE, “Railway applications. Wheelsets and bogies. Monobloc wheels. Technical approval procedure. Part 1: Forged and rolled wheels. UNE-EN-13979-1:2006”, Asociación Española de Normalización (UNE), Technical Standard, 2011.

This experimental research is intended to research on noise generation of rolling surfaces. This problem is important in bearings, railroad transport and many technical applications. Experimental research was performed in such a way that noise and vibration from any technical equipment didn’t interfere; only ambient vibration and noise influenced measurement. Tests were performed on special setup, which is described in the paper. Parameters of vibrations on steady plane and noise in surroundings of rolling cylinder were registered. For this purpose three sets of test surfaces with different roughness parameters were performed. It was experimentally proven that dry and lubricated surfaces generate different noise sound frequencies, found some interest dependencies on connection between generated vibrations and sound. The proposed technique can be applicable to bearing noise evaluation, especially when special materials are used. Research brings useful results, which can be used to estimate noise in newly designed devices. Finally, conclusions on results are made.

A computer aided tool for tire sound quality evaluation was developed. Automotive engineers can evaluate a tire structure by listening to synthesized sound that the tire would radiate when it rolls on a specific type of road surface. Among three kinds of tire sound, this study dealt with only the tire sound that radiates through its structural vibration caused by road surface texture excitation. The tool can be used on personal computers. To make it happen, tire sound radiation process is modeled into two parts. One is excitation. Tire deformation at the contact patch was calculated from road surface texture database by rolling contact analyses using multi-body dynamics simulation software. The model includes rolling tire structure model with contact compliance and simple suspension system for the wheel axle. Observation of the calculation results gives such an insight that excitation waveforms from road surface have prominent peaks that occur only at high peaks isolated from others, and do not have dips. This transformation process from road surface waveform to excitation is more accurate than tire envelope model and also not prohibitive considering today’s low-price computing power. The other process is tire structure vibration response. By limiting the usage of tire structure models just in representing over all vibration modal responses to road surface excitations in relatively low frequency range, a simple structural finite element model (FEM) was created. In this FEM, tire wall composite structures are modeled as assembly of solid elements with uniform material properties. The trick in using this FEM model lies in its boundary condition setting. By measuring vibration transfer functions from many points on a contact patch to tire tread and sidewalls, excitation in the middle of the contact patch was found to be blocked to travel to the sidewalls in higher frequency range due to the contact restriction on the periphery of the patch. This finding is essential in giving suitable boundary conditions to the FEM model and choosing the excitation points. To make the computing time minimum for synthesis, the vibration responses of the tire are represented by infinite impulse response (IIR) digital filter banks. The waveform obtained by applying the measured road texture waveforms to the IIR filter, was transferred to sound waves by the sound command of Matlab. By modifying the IIR filter, automotive engineers can judge the effect of tire structural design changes.