Open Access
Combining soft computing techniques and the finite element method to design and optimize complex welded products
(IOS Press, 2015) Lostado Lorza, Rubén; Fernández Martínez, Roberto; Mac Donald, Bryan J.; Villanueva Roldán, Pedro; Ingeniería; Ingeniaritza
Open Access
Diseño de un nuevo motor de explosión de dos tiempos con etanol como combustible
(DYNA, 2012) Lostado Lorza, Rubén; Villanueva Roldán, Pedro; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta Proiektuak
Actualmente, el mecanismo en el cual están basados la mayoría de los motores de explosión mono o pluricilindricos y que montan los vehículos convencionales, es el tradicional mecanismo cigüeñal-biela-pistón. En este mecanismo, el pistón tiene la posibilidad de girar con respecto a la biela y de friccionar con las paredes del cilindro a medida que éste se desplaza por su interior. La fricción entre el pistón y las paredes del cilindro puede ocasionar un desgaste excesivo tanto del interior del cilindro como del propio pistón, y, en el peor de los casos, incluso un atascamiento (o gripaje) del pistón en su recorrido o carrera. Para reducir este desgaste y evitar los indeseables gripajes, los motores requieren de sofisticados circuitos de engrase, los cuales han de proporcionar una película lubricante homogénea y constante entre las paredes del cilindro y las paredes del pistón. En este artículo, se ha diseñado un nuevo motor de explosión reemplazando el mecanismo cigüeñalbiela- pistón tradicional, en el que el émbolo se desplaza con un movimiento alternativo rectilíneo, por un sistema en el que el émbolo describe un movimiento alternativo circular. En este nuevo sistema, el pistón está unido rígidamente a la biela mediante pasadores, suprimiendo el giro del pistón y evitando su contacto con las paredes interiores del cilindro. Esta restricción de giro, reduce tanto el desgaste del pistón y del cilindro como el consumo de aceite lubricante. El motor diseñado funciona con etanol, y su ciclo termodinámico es el de un motor de dos tiempos. En este motor, la admisión de la mezcla airecombustible se realiza mediante lumbreras laterales y el escape de los gases productos de la combustión a través de una válvula situada en la parte superior de la cámara de explosión hemisférica.
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
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
Design of an electromagnetic servo brake with ABS function
(Trans Tech Publications, 2015) Lostado Lorza, Rubén; Somovilla Gómez, Fatima; Corral Bobadilla, Marina; Villanueva Roldán, Pedro; Fernández Martínez, Roberto; Ingeniería; Ingeniaritza
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
Recovered foam impact absorption systems
(MDPI, 2024-10-19) Marcelino Sádaba, Sara; Benito Hernández, Pablo; Martín Antunes, Miguel Ángel; Villanueva Roldán, Pedro; Veiga Suárez, Fernando; Ingeniería; Ingeniaritza
The use of foam materials in environments where they come into contact with individuals often results in deterioration, necessitating periodic replacements to maintain safety and hygiene standards. Foam, a lightweight, porous plastic formed by aggregated bubbles, possesses excellent impact-absorbing properties; however, its inherent porosity and susceptibility to wear present challenges. This project aims to develop a technological application for repurposing spent polyurethane (PU) foam from leisure facilities into effective impact absorption systems. By focusing on the reuse of deteriorated foam materials, this initiative seeks to minimize environmental impact while leveraging their beneficial technical characteristics. Addressing issues related to foam degradation, this project endeavors to create sustainable solutions by reintegrating spent foam into new systems. This innovative approach promotes sustainability while enhancing safety through the provision of high-quality, impact-resistant elements. Ultimately, this work aims to contribute to environmental conservation and the advancement of effective impact protection measures in leisure facilities.
Open Access
Pugh's total design: the design of an electromagnetic servo brake with ABS function - a case study
(SAGE, 2016) Villanueva Roldán, Pedro; Lostado Lorza, Rubén; Corral Bobadilla, Marina; Ingeniería; Ingeniaritza
Open Access
Análisis de sensibilidad de los parámetros de configuración de un proceso de soldadura GMA
(AEIPRO, 2011) Villanueva Roldán, Pedro; Ibarra Murillo, Martín; Sanz García, Andrés; Lostado Lorza, Rubén; Ingeniería; Ingeniaritza
El proceso de soldadura GMA en la fabricación de componentes mecánicos es una técnica difícil de ajustar debido al elevado número variables de configuración necesarias. A pesar de ello, dicho proceso se ha aplicado con éxito en múltiples sectores a lo largo del siglo XX. El ajuste óptimo de las variables de configuración es una tarea complicada ya que las desviaciones producen un incremento en las tensiones y deformaciones residuales en la pieza resultante. En el presente trabajo, un análisis de sensibilidad fue realizado para determinar la influencia de cada uno de los parámetros de configuración del proceso y posteriormente, poder establecer un orden de importancia. Un caso práctico de la soldadura de dos placas de acero fue realizado para realizar una lectura de datos y aplicar el análisis de sensibilidad.