Modelización, simulación y caracterización acústica de materiales para su uso en acústica arquitectónica

El objetivo global del estudio que esta memoria de tesis presenta consiste en evaluar la viabilidad de aplicar nuevos materiales absorbentes del sonido que intentan, por un lado, ser una alternativa a los clásicamente utilizados (como las lanas minerales) y, por otro, ofrecer una solución a una de las problemáticas actuales más importantes, como es el dar salida a los productos de desecho de las industrias textiles mediante el reciclado. Para ello, se han estudiado algunos de los parámetros que permiten caracterizar el comportamiento acústico de los materiales absorbentes del sonido (tales como la impedancia acústica, el coeficiente de absorción acústica y la resistencia específica al flujo, entre otros). También se han descrito diversos métodos de medida experimentales utilizados para obtener estos parámetros acústicos. De los métodos presentados en este trabajo, se ha centrado la atención en los basados en el tubo de impedancia acústica (o tubo de Kundt). Esta técnica presenta ventajas, como la de requerir sólo un pequeño espacio en laboratorio así como probetas de los materiales a estudiar no demasiado grandes. El estudio se ha asentado sobre tres pilares fundamentales: modelización matemática, caracterización acústica de materiales y simulación numérica. En primer lugar, tras repasar los principales modelos y teorías utilizados en la evaluación acústica de los materiales absorbentes sonoros de tipo poroso y fibroso, se propone un nuevo modelo matemático y se demuestra su validez para el tipo de materiales estudiados. Con respecto a la caracterización acústica, se han realizado diversas campañas de mediciones con el fin de obtener el coeficiente de absorción acústica y la resistencia específica al flujo de diversos materiales. Por último se aplica, mediante un programa informático basado en el método de los elementos finitos, la técnica de la simulación numérica con el fin de contrastar los resultados obtenidos experimentalmente, así como para la evaluación de unJuliá Sanchis, E. (2008). Modelización, simulación y caracterización acústica de materiales para su uso en acústica arquitectónica [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/2932Palanci

Propuesta de integración de Design Thinking en la asignatura Design of Structural Systems

[EN] The objective of the present work is to propose the application of the Design Thinking (DT) methodology in the course of Design of Structural Systems in which different teaching-learning strategies are being implemented. It is an applied subject to design and test different industrial products by learning a numerical simulation software. The course is taught in the fourth year of the degree in Engineering in Industrial Design and Product Development. The main methodology used is Problem-Based Learning (PBL) blended with the experience of teaching the subject through the English language (English as Medium of Instruction, EMI) to promote the learning of technical and specific vocabulary of the Engineering in Industrial Design and Product Development. In addition, the Flipped Classroom methodology has also been integrated and is beginning to be applied. The combination of the different strategies has been a satisfactory experience for the students and now it is proposed to integrate these methodologies in the Design Thinking philosophy.[ES] El objetivo del presente trabajo es proponer la aplicación de la metodología Design Thinking (DT) en la asignatura Design of Structural Systems en la cual se están aplicando distintas estrategias de enseñanza-aprendizaje. Se trata de una asignatura aplicada al diseño y comprobación estructural de diferentes productos industriales a partir del aprendizaje de un software de simulación numérica. La asignatura se imparte en cuarto curso del grado en Ingeniería en Diseño Industrial y Desarrollo de Productos. La principal metodología utilizada es la del Aprendizaje Basado en Problemas (ABP) junto con la experiencia de impartir la asignatura en lengua inglesa (English as Medium of Instruction, EMI) para favorecer el aprendizaje de vocabulario técnico y específico del Grado en Ingeniería en Diseño Industrial y Desarrollo de Productos. Además, desde hace unos años también se ha integrado la metodología de Docencia Inversa, que se está comenzando a aplicar. La combinación de las diferentes estrategias ha resultado una experiencia satisfactoria para los estudiantes y ahora se propone integrar estas metodologías en la filosofía de Design Thinking.Juliá Sanchis, E.; Martín Rubio, I. (2021). Propuesta de integración de Design Thinking en la asignatura Design of Structural Systems. En IN-RED 2021: VII Congreso de Innovación Edicativa y Docencia en Red. Editorial Universitat Politècnica de València. 187-194. https://doi.org/10.4995/INRED2021.2021.13670OCS18719

Experimental and Numerical Acoustic Characterization of Laminated Floors

[EN] This work has focused on characterizing laminated floors from the sound perception perspective. There are two main aspects in this work. The first is an alternative proposed for experimental characterization, which consists in recording the sound generated by the impact of a steel ball when it falls on a laminated floor from a known height. The second is a numerical hybrid FEM-FDTD model. The numerical model uses FEM to simulate the mechanical part of the experiment when the ball impacts the floor. The results are implemented into a FDTD algorithm to take into account the acoustic part of the problem and to obtain the sound pressure level of the microphone. This numerical model is useful for identifying laminated floors if the mechanical properties of the material are known, and to characterize them from the sound perception perspective.Gadea Borrell, JM.; Segura Alcaraz, JG.; Juliá Sanchis, E. (2015). Experimental and Numerical Acoustic Characterization of Laminated Floors. Experimental Techniques. 40(2):857-863. doi:10.1111/ext.12132S85786340

IMPACT ACOUSTIC ISOLATION OF ETHYLENE VINYL ACETATE PANELS

[EN] Ethylene Vinyl Acetate (EVA) foam is used in fitness facilities floors because of its shock absorption and isolation properties. Varying some material properties such as density and thickness, a range of these materials have been studied in order to evaluate their dynamic and acoustic behaviour. Two material properties (dynamic stiffness, and sound absorption coefficient) have been characterized according to the corresponding standards: ISO 9052 and ISO 10534-2. The results provide useful information to evaluate the influence of the density and thickness in the dynamic and acoustic behaviour of these materials.Segura Alcaraz, JG.; Juliá Sanchis, E.; Gadea Borrell, JM. (2015). IMPACT ACOUSTIC ISOLATION OF ETHYLENE VINYL ACETATE PANELS. ANNALS of the UNIVERSITY of ORADEA. Fascicle of Management and Technological Engineering. XIV:245-248. http://hdl.handle.net/10251/99708S245248XI

Teaching based on challenges for the subject steel structures

[EN] The evolution of information and communication technologies has changed the way in which agents involved in teaching have access to information. The classic concept of transmission of knowledge, valid 30 years ago, of a lecture (message) in a physical classroom (space) at a certain time (time) has now become obsolete. There are many disciplines taught in universities that can adapt their teaching model to hybrid face-to-face and online systems, where class time is used in the application and discovery of knowledge by the student. In this paper, a learning methodology based on challenges is proposed for the subject of Steel Structures of the Degree in Mechanical Engineering of the Universitat Politècnica de València. The organization of the contents and didactic tools used: tele-training platforms, flipped teaching, commercial software for steel structures ..., allows the teaching of the subject to be carried out face-to-face or online without changes and brings the student closer to the professional reality of steel structures. The results obtained during the last 5 years show a high percentage of passes and a high degree of student satisfaction based on surveys.Segura Alcaraz, JG.; Juliá Sanchis, E.; Montava-Belda, I.; Gadea Borrell, JM. (2021). Teaching based on challenges for the subject steel structures. EDULEARN Proceedings (Internet). 812-815. https://doi.org/10.21125/edulearn.2021.0219S81281

Learning mechanics of materials by doing models

[EN] Mechanics of Materials is a discipline taught to the second-year students in the Bachelor Degree of Mechanical Engineering at Universitat Politècnica de València, Alcoi Campus. The teaching-learning process is focused on three main aspects: theory, practice, and numerical simulations. There are several experiments designed to better understand the mechanical behaviour of the materials that are present in buildings and machines. This paper explains the application of another hands-on methodology that has been included in the course. It consists of completing the process by constructing or prototyping scale models which help the students to understand how the structures work in real life. The results of the experience allow us to consider that learning by doing has supposed a significant step in the comprehension of the Mechanics of Materials and the students have showed a positive attitude towards this activity. Not only by constructing models, but the fact that their construction is blended with other active methodologies, contribute to enhance the motivation in learning the subject.Montava-Belda, I.; Juliá Sanchis, E.; Gadea Borrell, JM.; Segura Alcaraz, JG. (2021). Learning mechanics of materials by doing models. EDULEARN Proceedings (Internet). 806-811. https://doi.org/10.21125/edulearn.2021.0218S80681

Sustainable multiple resonator sound absorbers made from fruit stones and air gap

[EN] This article investigates the sound absorption coefficient of materials manufactured from natural wastes. Fruit stones from some crops are one of the most available natural wastes in the Mediterranean Region. Recycled and vegetable products are becoming an interesting alternative to traditional materials to be used as sound-absorbing panels. Fruit stones can be profitable for a number of applications, such as biomass to produce energy. This research work intends to demonstrate that one of their applications can be ecological sound absorbers in building acoustics. Different four fruit stone samples, with different air gap volume percentages, display similar behaviour to multiple Helmholtz resonators (MHRs). By adding a 40 mm-thick rockwool layer, the sound absorption coefficients are compared for each sample. The experimental results allow establishing some analogies between MHRs and the new absorbing materials according to thickness, fruit type and the air gap volume. These fruit stones have been demonstrated as a good choice from acoustic and sustainable points of view.Juliá Sanchis, E.; Segura Alcaraz, JG.; Montava-Belda, I.; Gadea Borrell, JM. (2022). Sustainable multiple resonator sound absorbers made from fruit stones and air gap. Alexandria Engineering Journal. 61(12):10219-10231. https://doi.org/10.1016/j.aej.2022.03.0631021910231611

Spreadsheet solution of basic axial force problems of strength of materials

In this work, we present a spreadsheet developed for some particular problems of Strength of Materials. This paper is focused on the study of axial force systems, some statically determinate, such as trusses, and some statically indeterminate, such as a load-carrying rigid member supported by a pinned connection and by two axial bars. Starting with simple calculations for a particular problem, students develop the spreadsheet with more advanced calculations. The examples have been modelled on Microsoft Excel software. The aim is that, at the end of the course, students have developed a collection of such spreadsheets. This methodology contributes to enhancing the motivation in the study of the subject, which is the main learning objective.Juliá Sanchis, E.; Segura Alcaraz, JG.; Gadea Borrell, JM. (2010). Spreadsheet solution of basic axial force problems of strength of materials. Spreadsheets in Education. 4(1):1-11. http://hdl.handle.net/10251/62606S1114

Spreadsheet Solution of Basic Axial Force Problems of Strength of Materials

In this work, we present a spreadsheet developed for some particular problems of Strength of Materials. This paper is focused on the study of axial force systems, some statically determinate, such as trusses, and some statically indeterminate, such as a load-carrying rigid member supported by a pinned connection and by two axial bars. Starting with simple calculations for a particular problem, students develop the spreadsheet with more advanced calculations. The examples have been modelled on Microsoft Excel software. The aim is that, at the end of the course, students have developed a collection of such spreadsheets. This methodology contributes to enhancing the motivation in the study of the subject, which is the main learning objective

Textiles in architectural acoustic conditioning: a review

[EN] Environmental noise is a problem of increasing interest in advanced societies. Different types of textiles have properties which are suitable for the construction of elements able to condition sound in rooms. The use of these elements can foster acoustic comfort in all kind of rooms, both public and private. This work is a review of the possibilities and trends of textile materials in the field of acoustic conditioning. The use of textile materials for acoustic conditioning is widely extended. On the other hand, many efforts have been done in the last decades to understand the sound absorption mechanisms and to design materials and devices able to customize the sound space. Many of these new developments have used materials like wood, metal, plastic. Textiles can be thought as fully designable materials and potential base of composites, providing their unique technical and aesthetical characteristics to any ensemble.Segura Alcaraz, MP.; Bonet-Aracil, M.; Juliá Sanchis, E.; Segura Alcaraz, JG.; Montava-Seguí, I. (2022). Textiles in architectural acoustic conditioning: a review. Journal of the Textile Institute. 113(1):166-172. https://doi.org/10.1080/00405000.2021.1976483166172113