Open Access
Effect of the heat input on wire-arc additive manufacturing of invar 36 alloy: microstructure and mechanical properties
(Springer, 2022) Veiga Suárez, Fernando; Suárez, Alfredo; Artaza, Teresa; Aldalur, Eider; Ingeniería; Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Invar, also known as FeNi36, is a material of great interest due to its unique properties, which makes it an excellent alternative for sectors such as tooling in aeronautics and aerospace. Its manufacture by means of wire arc additive manufacturing (WAAM) technology could extend its use. This paper aims to evaluate the comparison of two of the most widespread WAAM technologies: plasma arc welding (PAW) and gas metal arc welding (GMAW). This comparison is based on the analysis of wall geometry, metallography, and mechanical properties of the material produced by both technologies. The results show a slight increase in toughness and elongation before fracture and worse tensile strength data in the case of PAW, with average values of 485 MPa for ultimate tensile strength (UTS), 31% for elongation and 475 MPa, 40% in GMAW and PAW, respectively. All results gathered from the analysis show the possibility of successful manufacturing of Invar by means of WAAM technologies. The novelties presented in this paper allow us to establish relationships between the thermal input of the process itself and the mechanical and metallographic properties of the material produced.
Open Access
Validation of the mechanical behavior of an aeronautical fixing turret produced by a design for additive manufacturing (DfAM)
(MDPI, 2022) Veiga Suárez, Fernando; Bhujangrao, Trunal; Suárez, Alfredo; Aldalur, Eider; Goenaga, Igor; Gil Hernández, Daniel; Ingeniería; Ingeniaritza
The design of parts in such critical sectors as the manufacturing of aeronautical parts is awaiting a paradigm shift due to the introduction of additive manufacturing technologies. The manufacture of parts designed by means of the design-oriented additive manufacturing methodology (DfAM) has acquired great relevance in recent years. One of the major gaps in the application of these technologies is the lack of studies on the mechanical behavior of parts manufactured using this methodology. This paper focuses on the manufacture of a turret for the clamping of parts for the aeronautical industry. The design of the lightened turret by means of geometry optimization, the manufacture of the turret in polylactic acid (PLA) and 5XXX series aluminum alloy by means of Wire Arc Additive Manufacturing (WAAM) technology and the analysis by means of finite element analysis (FEA) with its validation by means of a tensile test are presented. The behavior of the part manufactured with both materials is compared. The conclusion allows to establish which are the limitations of the part manufactured in PLA for its orientation to the final application, whose advantages are its lower weight and cost. This paper is novel as it presents a holistic view that covers the process in an integrated way from the design and manufacture to the behaviour of the component in use.
Open Access
Validation of the use of concept maps as an evaluation tool for the teaching and learning of mechanical and industrial engineering
(Springer, 2024) Veiga Suárez, Fernando; Gil del Val, Alain; Iriondo, Edurne; Eslava Adot, Urko; Ingeniería; Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This paper presents the experimental work developed to measure the learning process through concept map analysis. The development of a concept map is requested by the students for each chapter or theme of the subject. As a result, maps from engineering courses have been analyzed. The measurements carried out consider several parameters, such as individual and team map building, student progressive knowledge level, and map complexity. Concerning the complexity analysis, the focus is qualitative, and it is based on the data extracted from the concept maps elaborated by the students. The study, conducted during the 2018-2019 academic year, included students from various academic levels and institutions, such as the Public University of Navarra UPNA and the University of the Basque Country UPV-EHU, covering first-degree students of Bachelor's Degree in Mechanical Engineering and first-degree students of Master's Degree in Industrial Engineering at UPNA, third-degree students of Bachelor's Degree in Mechanical Engineering at UPV-EHU. The data collected from 37 individual maps in Industrial Drawing, 31 group maps in Industrial Drawing, 12 individual maps in Design of Machinery, and 12 group maps in Design of Machinery, along with a control group of 79 students who did not participate in any activity, provided valuable insights into the effectiveness of concept maps for evaluating understanding levels and learning outcomes across various engineering subjects and academic levels. The learning outcome of the students is treated to obtain the level of understanding of complex systems shown by the students through the concept maps previously drawn and the questionnaire answered by each student about the achievement of learning results through the use of concept maps. This work shows the research methodology established and the learning results achieved qualitatively: measuring the maps by means of a rubric, self-assessment based on a survey, and through the questionnaires. Also, the results obtained in the final exams have been compared. From the observed results, this methodology is presented as a suitable alternative for evaluating the correct acquisition of concepts in online teaching situations.
Open Access
Morphological design of a bicycle propulsion component using the hierarchical analysis process (AHP)
(MDPI, 2023) Villanueva Roldán, Pedro; Bona, Sergio; Lostado Lorza, Rubén; Veiga Suárez, Fernando; Ingeniería; Ingeniaritza
There are many mechanical and/or electrical energy storage devices nowadays which can be mounted on standard bicycles. The current trend regarding bicycle energy storage devices is to develop and improve electrical and electronic systems that can ease transportation. However, this paper shows the design process of a purely mechanical energy storage device, with no electrical components, which instead aims to entertain the user, producing a stimulus related to speed and physical exertion. The mechanical device has been designed according to an aspect or fashion known as steampunk, so that the mechanical elements forming the device (springs and spur gears) are visible to the user. The storage and discharge of energy are only produced by the user. In order to charge the device, after reaching an appropriate speed, the user uses the pedals in reverse motion. Alternatively, the mechanism can also be charged with a controlled braking system by actuating on a crank. The design process was based on the total design of Pugh and the AHP and QFD techniques.
Open Access
Cladding influence on the milling of low-stiffness aluminum alloy parts with local clamping
(Publicaciones DYNA, 2025-03-01) Casuso, Mikel; Rubio Mateos, Antonio; Silveira-Fernández, Elena; Veiga Suárez, Fernando; Lamikiz, Aitzol; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC
The milling of aeronautical skins on flexible and reconfigurable fixtures is a major industrial challenge due both to the low rigidity of the skins and to the configuration of these fixtures, which, although they provide a great versatility of use and are an efficient alternative to pollutant chemical milling, vibrations can easily occur in them that may impair the surface quality, increase the error of the final thickness and cause excessive cutting forces. Aiming to foster the use of flexible fixtures, a study of the natural frequencies and cutting forces obtained when milling thin parts has been carried out, with special emphasis on analyzing the influence of the cladding of aluminum alloy parts.
Open Access
Three-dimensional finite element modelling of sheet metal forming for the manufacture of pipe components: symmetry considerations
(MDPI, 2022) Bhujangrao, Trunal; Veiga Suárez, Fernando; Penalva Oscoz, Mariluz; Costas, Adriana; Favieres Ruiz, Cristina; Ingeniería; Ingeniaritza
The manufacture of parts by metal forming is a widespread technique in sectors such as oil and gas and automotives. It is therefore important to make a research effort to know the correct set of parameters that allow the manufacture of correct parts. This paper presents a process analysis by means of the finite element model. The use case presented in this paper is that of a 3-m diameter pipe component with a thickness of 22 mm. In this type of application, poor selection of process conditions can result in parts that are out of tolerance, both in dimensions and shape. A 3D finite element model is made, and the symmetry of the tube section generated in 2D is analysed. As a novelty, an analysis of the process correction as a function of the symmetrical deformation of the material in this case in the form of a pipe is carried out. The results show a correct fitting of the model and give guidelines for manufacturing.
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
Monitoring of blind rivets installations: contributions from the manufacturing chain and time-series imaging
(Elsevier, 2025-10-01) Penalva Oscoz, Mariluz; Gil del Val, Alain; Martín, Ander; Villanueva Roldán, Pedro; Uralde Jiménez, Virginia; Veiga Suárez, Fernando; Ingeniería; Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Fastening is a crucial operation in the aircraft manufacturing cycle, and the demand for automated solutions has grown in recent years. Blind rivets are particularly suitable for automation due to their ease of use. However, fastening with blind rivets requires indirect evaluation of the formed head for in-line quality monitoring. This study presents two approaches to address this problem. Firstly, an analysis of the drilling-riveting chain assesses the impact of the previous operation on riveting outcomes. Secondly, time-dependent signals from the riveting process are coded into images and analysed using deep learning techniques. Despite some limitations, both methods for monitoring blind riveting have demonstrated high precision and accuracy values above 0.9, with 1 indicating perfect precision or accuracy, suggesting that they can reliably predict the quality of rivet installations.
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.