Advances in Science and Technology Vol. 132

Abstract: Catapults are war instruments that have been used for centuries; the author of the first catapult is not known with certainty, although many scholars agree that their first appearance could have occurred in China. At first, they were operated by human power, with a dozen men pulling a rope to run the mechanism. Later came the trebuchet, an invention attributed to Mardi Ibn Ali al-Tarsusi, a type of catapult that uses the potential energy of a counterweight to launch the projectile further and with more power than with the old catapults. Today, we can find several mechanisms that use the same principle as the trebuchet. In this work, the geometrical modelling, the mechanical analysis, its functioning, and the actual scale reproduction of the device are carried out.

Abstract: The industrialization of Antequera went through an important development during the 19^th century. From this golden age, few factories remain. In general, they have been substituted entirely by other constructions or abandoned to deterioration. However, Antequera’s town hall is working towards the maintenance of the industrial and textile heritage of the area, with special programs focused on the recovery of the remains as museums, areas dedicated to education and special hiking routes around the textile factories. In this context, it is easy to recognize the need of special activities centered on reusing the facilities to preserve them in good shape. However, this is not an easy task because reuse can damage the heritage value of the assets under preservation. This paper explores the synergies between two methodological proposals for the enhancement of industrial immovable asset on which the authors have been working. One based on the use of drones, photogrammetry and reverse engineering and the other on the application of multi-criteria decision support techniques for the selection of new uses with less impact on the conservation of the heritage values of the analyzed asset. Results show that these two methodologies can work together for a better evaluation of the industrial assets, being drones an important resource for those assets that are difficult to access.

Abstract: Screw presses were machines widely used in various industrial sectors at the end of the 18th century and the beginning of the 19th century, among which the minting of coins stands out. In the Museum of the Royal Factories of Riópar (Albacete, Spain) there is a unique screw press, built in Paris at the beginning of the 19th century by the Delalande. Due to its structure and characteristics, it seems that its drive has been modified on at least two occasions, going from an initial design of a flywheel press with manual operation by several operators to the type of friction spindle with hydraulic wheel drive, for, to from 1940, be operated by an electric motor, as corresponds to its current configuration. Due to its age, characteristics and excellent state of conservation, this press is considered to have an important patrimonial and technological value. In the present work, we will proceed to the study of this screw press and the evolution of its typology throughout the two centuries of its existence. Its digital modeling is also considered, as well as the simulation of its operations. A comparative study of this press will be carried out with others of a similar structure, available at the Museum of the “Real Casa de la Moneda” of Segovia (Spain) and at the Museum “Casa de la Moneda” of the Fábrica Nacional de Moneda y Timbre (National Mint and Stamp Factory) in Madrid. Finally, it should be noted that this year marks the 250th anniversary of the creation of these Royal Factories, during the reign of Carlos III.

Abstract: Spain and Portugal share a common track gauge, different from the European standard gauge, and they have come to have 5 rail connections of which only 3 are currently active. On the two disused connections two different programs have developed for their respective protection, conservation, and valuation in the service of society. In the Spanish province of Salamanca, the route from the railway station of Boadilla-Fuente de San Esteban to the Portuguese border. This route has been recognized as a Bien de Interés Cultural (BIC) since 2000 and has been preserved including all the infrastructure and a good part of the railway superstructure. The Camino de Hierro program, at the final section, is a route of 17 km, conditioned for walking, crossing the Natural Park of Arribes del Duero. The program is managed by public initiative of the Diputación de Salamanca. On the other hand, we have the railway connection from Caceres to Valencia de Alcantara (last Spanish town) that then crosses into Portugal through Marvão-Beirã (first Portuguese station) to Torre das Vargens, where it connects with the route currently in use from Badajoz, through Elvas to main station of Entroncamento. Between the first two Portuguese stations, a private initiative (Rail Bike Marvão) has launched a program to make this 15 km route traversable on pedal-operated platforms on the railway and crossing the Serra de São Mamede Natural Park. This paper analyses both initiatives, identifying their strengths and weaknesses and the strategies employed as examples of good reference practices for similar initiatives, in order to identify key aspects which will be part of the criteria that the authors want to define as the initial phase of a methodology for the application of decision-making techniques in the management of these kind of assets.

Abstract: Additive Manufacturing (AM) represents a technology that provides access to part designs that are impossible or very difficult to achieve by any other manufacturing process. In addition to this consideration, the possibility of customization, and consequently, the almost immediate adaptation of dimensions and geometries makes the AM an exceptional alternative in the manufacture of prototypes. From the experience in the teaching of subjects in the Manufacturing Processes Engineering Area, it has been in different aspects of them that a special difficulty has been detected by the students in the spatial visualization of the concepts. A case of this, of special relevance, is that of the main cutting angles in a machining tool (with two cutting edges, main and secondary). In this work, a proposal for teaching innovation is proposed through the materialization of a removable model made with AM of a cutting tool in which different elements can be broken down, giving rise to the different angles indicated above. The students can operate with it, observing the angle of interest. The possibility of manufacturing with different polymeric, composite or metallic materials, of making modifications to the original designs to alter the contemplated angles and create new model configurations, the precise adjustment of the different pieces due to the non-appearance of a gap between them, the use of a wide range of colors for each piece or set of them, and changes in scale and so on, offer the possibility of expanding this work to any other type of cutting tools.

Abstract: In Engineering Schools, labs for teaching forming processes by means of material conservation methods are generally equipped with the appropriate equipment and tools to exemplify the theory received in class. However, the use of simulation techniques to complement the formation is not usually widely extended, since their learning is not usually trivial.One of the material conservation forming processes is sand casting. This process is of great educational significance, since the theory that defines it sets the basis for understanding other related moulding processes. In this context, the use of simulations of the moulding process allows the visualization of practical examples, helping to explain more clearly the theoretical information explained in class.Therefore, in this research a simulation assisted analysis has been developed using the Inspire Cast by Altair software, of teaching parts made in sand casting. First of all, students have been shown by means of simulations, the defects that can be originated in a part manufactured by sand casting. The study has been carried out by redesigning the risers involved in the distribution system of the process, by means of the Chvorinov's rule.Finally, a series of conclusions have been achieved, among which the following one stands out: if the functional performance of the part manufactured by sand casting is to be taken into account, the cooling modulus criterion must be selected for the design of the riser. Although, in principle, the material required for moulding is much larger, the defects generated in the part will be considerably reduced.

Abstract: Additive manufacturing (AM) has different dimensions with high potential, apart from the well-known ability to produce complex parts with great feasibility, minimum material, and without the need of expensive dies, among other advantages. Social, Environmental, Health, and Teaching and Learning are some examples of dimensions where AM can serve as an engine to promote economic changes, with special focus in depopulated areas. The “Teaching and Learning” dimension is key to promote global changes. There are two main approaches to incorporating additive manufacturing technologies into teaching and learning processes: active and passive integration of 3D printing. In this work, both approaches are considered through the example of some experiences in subjects of different disciplines such as manufacturing processes engineering and materials science. From the active approach, that is, acquiring knowledge and developing skills on AM techniques, the application of AM to generate crystal lattices of the inner structure of materials and the fabrication of patterns in foundry processes are presented as examples. Through these examples students develop skills related to design for additive manufacturing, selection of suitable materials and printing parameters, and postprocessing tasks. Form the passive approach, that is, the use of these technologies to support the learning process in technical subjects, three examples are shown: Bravais crystal lattices spatial configuration, design of foundry processes, and mechanical behavior of auxetic structures. These examples are useful to help our undergraduates understanding basic concepts that require spatial vision, as is the case of crystal lattices, improve foundry processes through the design of patterns, core boxes and casting distribution systems, and approaching to mechanical behavior of advanced materials, such as auxetic structures. This work aims to disseminate the potential of AM dimensions, such as Learning and Teaching, to boost fields of innovation.

Abstract: In the context of engineering studies, and specifically in courses related to manufacturing processes, student must solve practical problems by applying a high variety of knowledge and skills that should have been acquired from previous courses, such as statistics, geometrical and dimensional tolerancing, physics, materials and metallurgy, mathematics, etc. Therefore, it can be expected that the degree of assimilation and retention of knowledge reached at these first-year courses has a relevant influence on the students’ performance in later manufacturing courses. In this sense, during last years the authors have identified many errors in the students’ tests due to the deficient assimilation of basic concepts from previous courses, such as physical concepts (torque, power, energy, etc.) or mathematical concepts (inequalities, use of exponential functions and logarithms, trigonometry, properties of statistical distributions, etc.), among others. In this work, the students’ performance in manufacturing courses and the relationship with their competences in mathematics acquired in previous years are analyzed. For this purpose, the students’ background on these fundamental previous courses is analyzed through a test at the beginning of the semester. The study will be conducted on third-year courses in mechanical engineering, industrial engineering, and industrial design engineering degrees.