Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version

Development of Mathematical Models of a Human Virtual Ear

L’orecchio umano è un complesso sistema biomeccanico deputato alla ricezione e percezione del suono. Il presente lavoro di tesi verte sull’analisi delle parti esterna o media. Sono introdotti alcuni cenni di anatomia dell’orecchio esterno e medio ed una indagine di letteratura rivolta alla modellazione. È stato sviluppato un modello ad elementi finiti standard e generalizzati del canale uditivo e della membrana timpanica, a seguito di un approfondito confronto tra modelli di letteratura della membrana timpanica. Per la catena ossiculare, comprensiva di giunti, legamenti e tendini muscolari che la supportano, è stato adottato un approccio di tipo multibody. Il modello ad elementi finiti della membrana timpanica è stato combinato con il modello multibody della catena ossiculare al fine di ottenere un modello ibrido dell’orecchio medio. L’elaborazione dell’informazione nel sistema uditivo è un tema centrale della psicoacustica, una branca dell’acustica concernente la correlazione quantitativa delle grandezze fisiche e della percezione del suono. Un approccio psicoacustico è stato applicato in un’attività sperimentale e teorica per la valutazione del rumore da alzacristalli elettrici, nell’ambito di un progetto in collaborazione con un’azienda del territorio. The present thesis mainly focuses on the outer and middle parts of the human ear, which is a complex biomechanical system, devoted to sound reception and perception. The anatomy in brief and a model-oriented review of outer and middle ear are introduced. A model including the auditory canal and the tympanic membrane was developed applying standard and generalized finite element methods, following a thorough comparison between literature finite element models of the tympanic membrane. The multibody approach was adopted for the ossicular chain and supporting structures (joints, ligaments and muscle tendons). The tympanic membrane finite element model and the ossicular chain multibody model were combined in a hybrid finite element-multibody model of the middle ear. The information processing in the auditory system is a central issue of the psychoacoustics, a branch of acoustics concerning the quantitative correlation between the physical characteristics of sounds and their perceptual attributes. The psychoacoustic approach was applied in an experimental and theoretical activity on power window noise evaluation, within a project in collaboration with a local enterprise

Multibody dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: Formulations and Numerical Methods, Efficient Methods and Real-Time Applications, Flexible Multibody Dynamics, Contact Dynamics and Constraints, Multiphysics and Coupled Problems, Control and Optimization, Software Development and Computer Technology, Aerospace and Maritime Applications, Biomechanics, Railroad Vehicle Dynamics, Road Vehicle Dynamics, Robotics, Benchmark Problems. The conference is organized by the Department of Mechanical Engineering of the Universitat Politècnica de Catalunya (UPC) in Barcelona. The organizers would like to thank the authors for submitting their contributions, the keynote lecturers for accepting the invitation and for the quality of their talks, the awards and scientific committees for their support to the organization of the conference, and finally the topic organizers for reviewing all extended abstracts and selecting the awards nominees.Postprint (published version

Дослідження частотних характеристик імплантатів кісточок середнього вуха людини

У роботі розглядаються засоби для відновлення слуху людини у випадках, коли порушення слуху не зачіпають слуховий нерв. Тоді відновлення слуху здійснюється методами тимпанопластики - шляхом заміни (відновлення) барабанної перетинки або ланцюга слухових кісточок. В роботі досліджено імплантати, які виготовлено з біозамінних матеріалів, що дуже різняться за своїми механічними властивостями. Тому для індивідуального підбору осикулярних імплантатів при тимпанопластиці, в роботі розроблено фізичну модель імплантатів. На її основі визначено такий важливий параметр імплантатів, як значення їх резонансних частот. В роботі також проведено порівняння теоретичних значень резонансних частот імплантатів з експериментальними результатами їх вимірювання за допомогою оригінальної установки.The paper considers the means to restore human hearing in cases where hearing impairment does not affect the auditory nerve. Then the restoration of hearing is carried out by tympanoplasty - by replacing (restoring) the eardrum or chain of auditory ossicles. The paper examines implants made of bioreplaceable materials that differ greatly in their mechanical properties. Therefore, for the individual selection of ossicular implants in tympanoplasty, a physical model of implants was developed. Based on it, such an important parameter of implants as the value of their resonant frequencies is determined. It was found that the first resonant frequency for a cartilage implant is 61.1 MHz, and for a titanium implant - 487.2 MHz. The paper also compares the theoretical values of the resonant frequencies of implants with the experimental results of their measurement using the original installation. The acoustic part of the experimental setup was an electroacoustic emitter placed on an acoustic vibration absorber (paralon) and a sensitive microphone placed on a counterweight to reduce the pressure on the oscillary prosthesis during measurements and fix it. Signal from the laptop was fed to amplify the input of the audio interface, and from its output signal was sent to the electroacoustic emitter. Between the electroacoustic emitter and the microphone, through the additionally developed and manufactured duralumin nozzles, which provided the introduction of sound vibrations in the prosthesis at angles of 15, 30, 45, 60, a sample of the oscillary prosthesis was recorded. With the help of the installation, the transfer coefficients of samples of ossicular prostheses made of Teflon, titanium, cartilage and bone tissues were measured and compared. It is established that for high frequencies the level of transmission coefficients decreases faster with increasing angle than for low ones, due to the increase in the acoustic size of prostheses with increasing frequency. Also due to the general decrease in the signal level with increasing angle, you can see a decrease with a center frequency of 1 kHz. It is established that at the angle of incidence of the acoustic wave 30, for all samples of prostheses, at a frequency of 4 kHz there is a rise in frequency response. Moreover, for a titanium prosthesis, the value of the transmission coefficient at an angle of incidence of 30 at this frequency exceeds the value of the direct incidence of the acoustic wave

Акустичне поле ультразвукового приладу для диференційної діагностики слуху людини

В даній роботі проведено аналіз актуальності та новизни застосування багатоелементної решітки в електроакустичному перетворювачі для диференційної діагностики завитки внутрішнього вуха людини. Наве-дено розрахунки геометричних розмірів та акустичного поля для циліндричного хвильового фронту створюваного лінійною багатоелементною решіткою п'єзоелементів. Проведені розрахунки розподілу акустичного поля по гли-бині зі зміною куту відхилення від осі та тривалості імпульсу. Зроблено висновок про доцільність використання даного типу електроакустичного перетворювача для диференціальної діагностики слуху людини. З отриманих графіків з'ясували, що при збільшенні коефіцієнта згасання імпульсу призводить до зменшення значень дифракцій-ного максимуму. Також показано, що відносну амплітуду дифракційного максимуму можна зменшити шляхом зменшення тривалості імпульсу та збільшенням кількості п'єзоелементів у робочій групі. Цей тип п'єзоелектричного перетворювача дозволить при зміні кута випромінювання ультразвукової хвилі впливати на всі ділянки завитки людини та обирати певну тривалість для безпечного впливу.In this paper analyzes the relevance and novelty of using a multielement array in an electroacoustic transducer for differential diagnosis of human inner ear coagulation by changing the pulse duration and direction of radiation. Today the clinical applications of ultrasound are numerous and diverse, and ultrasound diagnostics is one of the most rapidly developing methods in medicine. In recent years the effect of focused ultrasound on the human auditory system has been actively studied. The structure of the human inner ear is in the middle of a system of spaces and channels of bony labyrinths. It is known that the most successful way to the auricular labyrinth is the one with the shortest distance and with the least tissue loss. In order for the width of the scanning ultrasound beam to remain constant throughout the entire length of probing, the mode of dynamic focusing of the ultrasound beam was considered. The ultrasonic beam in the scanners is formed using a linear multielement array with individual element dimensions of several wavelengths by introducing between the electrical signals sent or received from the elements such delays that ensure that the fields are focused at a given point on the beam axis, and additionally by using acoustic lenses. In practice, the problem is solved by successive focusing of the beam at several fixed distances from the working surface. Calculations of the geometric dimensions and the study of the acoustic field for the cylindrical wave front created by a linear multielement array of piezoelements are performed. Calculations of the acoustic field distribution in depth at var-ying pulse duration and at changing the angle of deflection from the axis, with the focal distance unchanged. It is concluded that it is reasonable to use this type of electroacoustic transducer for differential diagnosis of human hearing. From the obtained graphs it was found that an increase in the pulse attenuation coefficient leads to a decrease in the values of the diffraction maximum. It is also shown that the relative amplitude of the diffraction maximum can be reduced by reducing the pulse duration and increasing the number of piezoelectric elements in the working group. This type of piezoelectric transducer will allow, by changing the angle, to affect all parts of the cochlea of a person, as it is known that each part of the cochlea is responsible for a certain frequency of perception, pick up a certain duration for safe exposure. And it will also be possible to perform acoustic influence on the cochlea to confirm the functioning of the auditory nerves before cochlear implantation

Engineering Dynamics and Life Sciences

From Preface: This is the fourteenth time when the conference “Dynamical Systems: Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our invitation has been accepted by recording in the history of our conference number of people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcomed over 180 persons from 31 countries all over the world. They decided to share the results of their research and many years experiences in a discipline of dynamical systems by submitting many very interesting papers. This year, the DSTA Conference Proceedings were split into three volumes entitled “Dynamical Systems” with respective subtitles: Vibration, Control and Stability of Dynamical Systems; Mathematical and Numerical Aspects of Dynamical System Analysis and Engineering Dynamics and Life Sciences. Additionally, there will be also published two volumes of Springer Proceedings in Mathematics and Statistics entitled “Dynamical Systems in Theoretical Perspective” and “Dynamical Systems in Applications”

Dynamical systems : control and stability

Proceedings of the 13th Conference „Dynamical Systems - Theory and Applications" summarize 164 and the Springer Proceedings summarize 60 best papers of university teachers and students, researchers and engineers from whole the world. The papers were chosen by the International Scientific Committee from 315 papers submitted to the conference. The reader thus obtains an overview of the recent developments of dynamical systems and can study the most progressive tendencies in this field of science