Open Access
Diseño de un mecanismo de propulsión para bicicleta capaz de almacenar y descargar energía mecánica producida por el usuario
(AEIPRO, 2013) Villanueva Roldán, Pedro; Corral Bobadilla, Marina; Lostado Lorza, Rubén; Illera Cueva, M.; Bona, J; Ingeniería; Ingeniaritza
La energía eléctrica todavía proviene en su mayor parte de combustiones fósiles y soluciones no ecológicas. En este artículo se describe una alternativa a la bicicleta eléctrica. Se muestra el proceso de diseño de un dispositivo aplicable a una bicicleta, formado únicamente por elementos mecánicos siguiendo una moda retro o steampunk. Tiene por objetivo divertir al usuario, produciendo un estímulo directamente relacionado con la velocidad y el esfuerzo físico. Tanto el almacenamiento de energía, como la descarga de la misma, se produce a voluntad del usuario. Por un lado, una vez alcanzada una velocidad adecuada al gusto del usuario o cuando él así lo desee, da marcha atrás con los pedales cargando así el dispositivo. Por otro lado, mediante una palanca descargará la energía que ha acumulado previamente. El diseño del componente está basado en el diferencial utilizado en la dirección dentro del sector de automoción, así como en los engranajes dotados con resortes utilizados en los coches de juguete, los cuales almacenan energía al hacerlos rotar. El nuevo dispositivo combina estos elementos aplicando modificaciones en los mismos para que su efecto se adapte a los objetivos deseados.
Open Access
Automatic trajectory determination in automated robotic welding considering weld joint symmetry
(MDPI, 2023) Curiel Braco, David; Veiga Suárez, Fernando; Suárez, Alfredo; Villanueva Roldán, Pedro; Aldalur, Eider; Ingeniería; Ingeniaritza
The field of inspection for welded structures is currently in a state of rapid transformation driven by a convergence of global technological, regulatory, and economic factors. This evolution is propelled by several key drivers, including the introduction of novel materials and welding processes, continuous advancements in inspection technologies, innovative approaches to weld acceptance code philosophy and certification procedures, growing demands for cost-effectiveness and production quality, and the imperative to extend the lifespan of aging structures. Foremost among the challenges faced by producers today is the imperative to meet customer demands, which entails addressing both their explicit and implicit needs. Furthermore, the integration of emerging materials and technologies necessitates the exploration of fresh solutions. These solutions aim to enhance inspection process efficiency while providing precise quantitative insights into defect identification and location. To this end, our project proposes cutting-edge technologies, some of which have yet to gain approval within the sector. Noteworthy among these innovations is the integration of vision systems into welding robots, among other solutions. This paper introduces a groundbreaking algorithm for tool path selection, leveraging profile scanning and the concept of joint symmetry. The application of symmetry principles for trajectory determination represents a pioneering approach within this expansive field.
Open Access
Weld joint reconstruction and classification algorithm for trajectory generation in robotic welding
(Trans Tech Publications, 2023) Curiel Braco, David; Veiga Suárez, Fernando; Suárez, Alfredo; Villanueva Roldán, Pedro; Aldalur, Eider; Ingeniería; Ingeniaritza
Open Access
The integration of mechanical energy absorbers into rollover protective structures to improve the safety of agricultural tractors in the event of rollover
(MDPI, 2024) Alfaro López, José Ramón; Pérez Ezcurdia, Amaya; Latorre Biel, Juan Ignacio; Arana Navarro, Ignacio; Benito Amurrio, Marta; Villanueva Roldán, Pedro; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA1912
The combination of safety belts and rollover protective structures (ROPSs) is key in improving the safety of agricultural tractors in the event of rollover. However, we also have the opportunity to enhance the security provided by each ROPS; one such example is the combination of this safety device with adequate mechanical energy absorbers (MEAs). Inexpensive disc-shaped MEAs can be included in the anchoring points of a ROPS onto the chassis of a tractor. Three configurations of ROPS combined with MEAs were tested during the application of loads that simulated the effects of side rollover in the vehicle. The tested configurations included a blank MEA as a reference case alongside a single MEA and a stack assembly containing both elements. The results of the tests show that both the deformation of the ROPS itself and the strain energy are larger in the case of blank MEAs; thus, there is also a risk that the clearance zone will be infringed upon and that the protective structure will collapse. We can conclude that the implementation of an appropriate MEA in ROPS reduces the deformation of the ROPS itself and its strain energy in cases of vehicle rollover; hence, the safety provided by such protection systems may be improved at a low cost.
Open Access
Evaluation of the potential of natural mining by-products as constituents of stabilized rammed earth building materials
(MDPI, 2025-05-06) Martín Antunes, Miguel Ángel; Perlot, Céline; Villanueva Roldán, Pedro; Abdallah, Rafik; Seco Meneses, Andrés; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this investigation, different natural by-products were used to modify the Particle Size Distribution (PSD) of a soil to evaluate their potential in Stabilized Rammed Earth (SRE) building. Three different mixes were manufactured: (i) a mix composed entirely of a clayey soil, (ii) a mix consisting of mining by-products and clayey soil and (iii) a mix entirely based on mining by-products. Unstabilized and stabilized samples of the mixes were manufactured using two cement dosages (2.5% and 5%), and the samples were tested for Unconfined Compressive Strength (UCS), soaked UCS, and wetting and drying tests. Mining by-products demonstrated significant potential in SRE building, as their addition to the clayey soil resulted in higher UCS values compared to the UCS obtained from clayey soil alone. Unstabilized samples lost their integrity during exposure to water. The inclusion of mining by-products also showed potential as, although the mixes did not fully meet the requirements for soaked UCS and the wetting and drying tests, the mix containing both mining by-products and clayey soil retained its integrity in water, unlike the samples composed solely of clayey soil. M3C5 successfully met the requirements for soaked UCS and the wetting and drying tests, further highlighting the great potential of mining by-products in SRE building.
Open Access
Design and optimization of an electromagnetic servo braking system combining finite element analysis and weight-based multi-objective genetic algorithms
(Springer, 2016) Lostado Lorza, Rubén; Villanueva Roldán, Pedro; Fernández Martínez, Roberto; Mac Donald, Bryan J.; Ingeniería; Ingeniaritza
Open Access
Modeling of MAG welding process using data mining techniques
(AEIPRO, 2011) Villanueva Roldán, Pedro; Ibarra Murillo, Martín; Lostado Lorza, Rubén; Sanz García, Andrés; Ingeniería; Ingeniaritza
La fabricación de componentes mecánicos mediante soldadura eléctrica es un proceso que se lleva aplicando con éxito en diferentes sectores desde comienzos del siglo XX (Automoción, Construcción, Aeronáutica…). Este proceso de fabricación presenta siempre el inconveniente de inducir sobre el componente fabricado elevadísimas tensiones y deformaciones residuales, obligando a un mecanizado posterior hasta poder ajustar a las tolerancias de diseño. El mecanizado posterior supone siempre un sobrecoste en el precio total de fabricación del componente soldado, aumentando este según el grado de mecanizado requerido. En este trabajo se expone la experiencia adquirida en la modelización del proceso soldadura MAG mediante técnicas de Minería de Datos. El objetivo principal es encontrar modelos predictivos de deformaciones angulares y de los espesores de los cordones de las soldaduras en función de los parámetros de configuración de la máquina de soldeo (intensidad, velocidad, ángulos, etc.), así como identificar los factores mas influyentes en la generación de las tensiones y deformaciones residuales.
Open Access
Determination of the most influential factors on the quality of resin gears manufacturing
(MDPI, 2025-08-12) Echeverria Lazcano, Angel María; Martín Antunes, Miguel Ángel; Villanueva Roldán, Pedro; Fuertes Bonel, Juan Pablo; Marcelino Sádaba, Sara; Ingeniería; Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA2023-11383
The manufacture of industrial parts using silicone molds is becoming more frequent due to their versatility, durability, and precision, particularly in the production of complex components. One specific application is the manufacture of gears, which play a fundamental role in high-performance mechanical systems, where geometric accuracy is essential. Gears produced from resins offer several advantages such as efficient tribological performance, load resistance, noise reduction, and non-magnetic properties. The main goal of this paper is to determine the main factors affecting the final quality of resin gears by analyzing two principal gear quality parameters: teeth profile (ffα) and helix deviation (ffβ). This work includes a global analysis of all contributing factors influencing the final quality of gears manufactured. One of the main conclusions obtained is that gear quality depends on a combination of factors, such as mold properties, choice of resin, the manufacturing process, and the quality of the original model. As a result, two regression equations have been developed, relating all influencing factors to the two gear quality parameters (ffα and ffβ). Different response surfaces have been obtained, enabling the definition of the required quality level of the model to achieve reproductions with certain ffα and ffβ values suitable for the intended application conditions.
Open Access
Benefits of aeronautical preform manufacturing through arc-directed energy deposition manufacturing
(MDPI, 2023) Suárez, Alfredo; Ramiro, Pedro; Veiga Suárez, Fernando; Ballesteros Egüés, Tomás; Villanueva Roldán, Pedro; Ingeniería; Ingeniaritza
The paper introduces an innovative aerospace component production approach employing Wire Arc Additive Manufacturing (WAAM) technology to fabricate near-finished preforms from Ti6Al4V titanium. Tensile tests on WAAM Ti6Al4V workpieces demonstrated reliable mechanical properties, albeit with identified anisotropic behavior in horizontal samples, underscoring the need for optimization. This alternative manufacturing strategy addresses the challenges associated with machining forged preforms, marked by a high Buy To Fly (BTF) ratio (>10), leading to material wastage, prolonged machining durations, elevated tool expenses, and heightened waste and energy consumption. Additionally, logistical and storage costs are increased due to extended delivery timelines, exacerbated by supply issues related to the current unstable situation. The utilization of WAAM significantly mitigates initial BTF, preform costs, waste production, machining durations, and associated expenditures, while notably reducing lead times from months to mere hours. The novelty in this study lies in the application of Wire Arc Additive Manufacturing (WAAM) technology for the fabrication of titanium aircraft components. This approach includes a unique height compensation strategy and the implementation of various deposition strategies, such as single-seam, overlapping, and oscillating.
Open Access
Methodology for the path definition in multi-layer gas metal arc welding (GMAW)
(MDPI, 2023) Curiel Braco, David; Veiga Suárez, Fernando; Suárez, Alfredo; Villanueva Roldán, Pedro; Ingeniería; Ingeniaritza
The reconstruction of the geometry of weld-deposited materials plays an important role in the control of the torch path in GMAW. This technique, which is classified as a direct energy deposition technology, is experiencing a new emergence due to its use in welding and additive manufacturing. Usually, the torch path is determined by computerised fabrication tools, but these software tools do not consider the geometrical changes along the case during the process. The aim of this work is to adaptively define the trajectories between layers by analysing the geometry and symmetry of previously deposited layers. The novelty of this work is the integration of a profiling laser coupled to the production system, which scans the deposited layers. Once the layer is scanned, the geometry of the deposited bead can be reconstructed and the symmetry in the geometry and a continuous trajectory can be determined. A wall was fabricated under demanding deposition conditions, and a surface quality of around 100 microns and mechanical properties in line with those previously reported in the literature are observed.