This website serves as a support for my application to the University of Porto Excellence Award in Scientific Research 2024.
I am a Full Professor at the Mechanical Engineering Department of the Faculty of Engineering of the University of Porto (FEUP), and I have established the Advanced Joining Processes Unit of the Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), a research group mainly dedicated to the study of structural joining processes, such as adhesive bonding, welding and mechanical joining, joining of biological materials and also active in the design of advanced testing equipment. The unit also carries out research in pedagogical matters related to engineering education.
Research in these fields is organized into six different groups, all undertaking cutting-edge research with disruptive work, supported by dissemination activities with the edition of journals, the organization of conferences and technology transfer activities. All of these groups operate with an objective-based approach, without fixed schedules but with regular weekly meetings. These meetings are crucial to share experiences, assess progress and implement changes and correction in the work plans. These six groups are schematically presented in Figure 1.
 |
 |
 |
 |
 |
 |
During my career as an academic, I have always targeted excellence innovation, achieved both through extensive dissemination and technological transfer activities. I received the FEUP Scientific Excellence Award in both 2013 and 2018 and I am Editor-in-Chief of seven peer-reviewed journals. Two of these journals are oriented towards general research dissemination in engineering: the UPorto Journal of Engineering, which provides a highly visible outlet for the scientific publication generated in the engineering field within the University of Porto and Discover Mechanical Engineering, an open access journal publishing research across all fields relevant to mechanical engineering.
An underlying philosophy of my research is that scientific output is fundamental to increase visibility and further the establishment of industrial and academic interactions. Accordingly, we aim for high quality, consistent and impactful publications, demonstrated by more than 30 books, around 60 book chapters and nearly 500 ISI indexed scientific publications, which have received almost 18500 citations and correspond to an h-index of 71 (Scopus). Through extensive publication, the quality and the visibility of our work has generated significant industrial interest, which has fostered consistent growth and led to 65 different cooperation and consulting activities with industrial partners. We have also developed novel testing device to support these activities, leading to 15 patent requests. Currently, I manage a team of nearly 40 researchers, supported by a yearly budget of around 1 million euros, 50% of which is sourced from industrial partners.
In this website you can find the supporting documents for my application to this award.
Lucas F M da Silva
Full Professor at Faculty of Engineering of the University of Porto
As stated in the introduction, the scientific work I carry out is divided into six main research areas, each managed by a research group. The following subsections provide detailed information on these groups, listing key research activities, projects and dissemination and publication activities.
Adhesive bonding is the genesis of our research group, and for more than 20 years we have been performing extensive research work in adhesive characterization, working in partnership with major industrial players such as Aston Martin, Sika, John Deere, General Motors, Dupont, Embraer, Alstom and Honda, operating in the automotive, aerospace and railway sectors. These are all key clusters of the Portuguese economy and such cooperations have allowed us to bring knowledge and added value to these important sectors. We are also well-known for developing techniques to improve the mechanical performance of bonded joints, which include hybrid, mixed-adhesive and graded joints. Graded joints locally vary the properties of the adhesive layer to minimize stress concentrations and maximize performance and were first experimentally demonstrated during a PhD thesis I have supervised. We have recently developed multiple solutions for bonding composite materials, increasing interlaminar strength through surface toughening methodologies or the use of fibre metal laminates.
Advanced joint design concepts with complex materials can only be developed with the support of numerical modelling, using cohesive elements with experimentally determined mechanical properties and that can precisely predict damage and failure under varied conditions. Simpler analytical models have also been developed to facilitate joint design, such as those integrated in JointDesigner, an easy-to-use web application (shown in Figure 2) we created and used by the industry and academy alike, supporting practical classes at FEUP.
After mastering the design and optimization of joints for short-term conditions, we devoted our attention to durability, a major industrial concern. We have developed testing and design procedures that account for temperature, moisture, creep and fatigue loads in joint performance. In particular, we have carried out disruptive work on the subject of fatigue, developing two distinct design methodologies. One employs a fracture mechanics approach, modelling damage generated by fatigue in a joint and the resultant progression of the crack, known as the fatigue crack growth approach. The other approach is the total fatigue life approach, or S-N approach, determining the conditions that lead to crack initiation and thus the life of the joint. Both design methodologies are experimentally validated and implemented by many of our industrial partners, such as John Deere, Sika and Volvo.
Another issue that still limits wider use of adhesive bonding is the lack of effective non-destructive testing (NDT). In response, we are developing novel defect detection processes based on the response of defective joints to mechanical wave propagation, using machine learning to interpret the data generated (shown in Figure 3). We have achieved promising results in the detection of weak adhesion, which is practically invisible to state-of-the-art NDT methodologies and thus a “holy grail” in this field. Process control is another hot topic in bonding, aiming to precisely model the flow and gap filling capabilities of the adhesive. While our body of work in this matter is not yet extensive, we will dedicate more attention to this subject while leading a European SMART-EUREKA network project, starting its activities in the coming months.
We are responsible for training personel that will work in high responsibility bonding operations, organizing the European Adhesive Bonder Course, which trains bonders according to the European Welding Federation standards. Furthermore, we also organize custom courses for companies, targeting specific needs. We have provided training for many partners, including General Electric Power, John Deere and Volkswagen and this allow us to transfer all our research experience and knowledge directly to the industrial sector.
All our experience and impact in the subject of adhesive bonding is patent in the "Handbook of Adhesion Technology (2nd Edition)", a comprehensive reference book which I have authored and edited and is consistently the most cited publication in this field (Figure 4), according to Google Scholar.
I am editor in chief of a leading journal in the field of adhesive bonding, The Journal of Adhesion and the Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications and also organize international scientific conferences, including the International Conference on Structural Adhesive Bonding (AB), the International Conference on Industrial Applications of Adhesives (IAA) and the International Conference on Materials, Design and Applications (MDA).
During the last five years, the group has evolved from being solely dedicated to just adhesive bonding and now covers multiple advanced joining processes, including joining by plastic deformation. This follows a desire to establish a structure similar to that employed by German research groups, such as that led by Professor Uwe Reisgen, which encompass all aspects of joining. This is especially relevant in light of the current transition towards cleaner mobility, hinged on lightweight materials and efficient joints. We are working to be a reference in all joining methods and now run projects studying novel processes, such as a highly efficient hole hemming joining process, able to join metals and polymers. This process is shown numerically in Figure 5.
This research has been leveraged to form a consortium, dedicated to automotive battery pack manufacturing, which seeks to find new methods to join cells, conductors and housings of high voltage batteries. This is a very active research topic, driven by the transition to electric vehicles and our contribution is to develop novel plastic deformation processes which simplify the battery manufacturing and improve performance, including the aforementioned hole hemming process. This consortium, which we lead, is fully funded by its industrial partners, which include Sabic, Volvo, Momentive, ABEE, and Aston-Martin, which shows its high industrial relevance.
To further the dissemination in this field, I have also founded the Journal of Advanced Joining Processes which, while recent, already consistently publishes high-quality works in all aspects related to joining, a Q1 journal with an impact factor of 4.1. I also organize the International Conference on Advanced Joining Processes (AJP), which gathers the leading experts in this field and has been crucial to establish new partnerships in this area.
As described above, the research of the group was complemented in the last five years by carrying out research in multiple joining processes and this has led to the establishment of a new research group dedicated to welding. Currently, we focus our research mainly on laser and friction stir welding, addressing industry relevant topics such as intermetallic formation in dissimilar welding, the minimization of residual stresses and heat inputs, thin sheet hybrid joining and increasing the flexibility of joint design. Of special note are our recent works in the development of a novel buttering technique for friction stir welding of dissimilar metals, avoiding the formation of brittle intermetallic compounds. A short video of a thermal simulation of a friction stir welding process is shown in Figure 6.
We are leading a large scale research project studying welded joints for the automotive industry, combining the capabilities of three LAETA laboratories (INEGI at Porto, IDMEC at Lisbon and ADAI at Coimbra). This project looks at welded joints from different perspectives, which include the metallography and mechanics of the welded connection, the dynamic characteristics of the bonded joint and its interaction in the vehicle behaviour and finally the full life cycle analysis and environmental impact. Aston-Martin is a key partner in this project, supplying engineering data on actual welded vehicle structures.
We have prepared a reference book on the subject of modelling welding processes, titled "Computational Concepts in Simulation of Welding Processes" and are currently writing another dedicated to the welding processes of aluminum alloys. Finally, both the aforementioned Journal of Advanced Joining Processes and the International Conference on Advanced Joining Processes (AJP) I organize are also essential to support our contribution to this field.
More recently, we have invested in researching joining of biological and bio-based materials and thus have established a dedicated research group in this subject, seeking to make use of all our knowledge and experience in the field of joining to address new problems. We have previously explored the use of cork to reinforce adhesives in a functionally graded manner, seeking to improve the toughness of these often brittle materials using this naturally sourced material with unique properties. The magnetically coated material is seen on Figure 7.
Currently, we are still working towards more sustainable bonded structures, leading a nationally funded project (FCT) to design joints employing bio-based materials such as densified wood, cork and bio-adhesives. We are also developing fully recyclable bonded structures which perform comparably to those made with metals or synthetic composites.
More recently, we have are starting an innovative research project dedicated to developing a bonding process for horseshoes, avoiding the classical methods which use nails and can cause damage to the horse hoof. This project is fully funded by Mustad, the world leading company in the hoofcare sector. We are also currently writing a reference book on this subject to be published by Elsevier in 2025, titled "Bio-joining: Adhesion in biomaterials, biological adhesives and biomimetic adhesive systems", which will provide a comprehensive and up to date summary of the state of the art in this field.
To support cooperation and knowledge sharing in this specific field I have established and will chair the International Conference on Bio-joining (BJ), which will have its first occurrence in December 2024. We are also preparing a new journal in this field, to complement and reinforce our contribution to this field.
Since most of the research carried out in the group involves an important experimental component, the group has naturally developed competences in the development of advanced testing equipment. By involving students and professors in this development process the group has been able to produce complex machine designs, including advanced testing machines able to precisely characterize materials under extreme conditions. These include torsion loads, strain rate, creep, fatigue and extreme temperatures. We are currently undertaking the design and manufacture of an innovative machine to mechanically characterise weak snow layers, which will provide crucial data to support investigation on the formation and the avoidance of avalanches. As an output, this work has led to 15 national and international patent requests. As machine design currently represents a substantial part of our research, we have set up the Journal of Machine Design and Automation Intelligence and organize the International Conference on Machine Design (MD) to increase our impact and commitment to this field. Figure 8 shows the design and development process of a torsion machine, created for adhesive characterization.
I also have a passion for the pedagogical aspects of my role as an academic and strive to provide the best conditions possible for my students in an inclusive and diverse environment. I supervised the youngest ever PhD recipient at FEUP and the first doctoral candidate from East-Timor to conclude his PhD at FEUP. I was awarded with the Pedagogical Excellence Award from FEUP in 2023 and have established a research group on pedagogical matters. We have researched the discrimination of women in mechanical and industrial engineering roles, the motivation and integration of foreign students (Brazilian and Iranian) at FEUP, analysed the research and teaching performance of the mechanical engineering teaching staff and identified misconceptions in the correlation of students learning styles, their beliefs on intelligence and academic performance.
I have carried out a research work seeking to introduce a theatrical element to expositional classes, employing techniques which capture the students attention and present the contents in a more engaging form. Based on the lessons gathered from this work, I am currently undertaking a year long project to create high quality videos of the classes I teach, seeking to provide the students with the additional tools to support their learning process. An example of a video produced under this project is shown below in Figure 9.
Seeking to assemble world leading education researchers in a common forum, I have created the International Conference on Science and Technology Education (STE), which first took place in 2020, and I am Editor-in-Chief of International Journal of Mechanical Engineering Education. I am also a founding member of an association dedicated to supporting the work of women in science, technology, engineering, and math fields, which will first convene on the 9th of May, 2024.
