Interview of Julien, postdoc' researcher at IBOIS

VP: What is your career path?

JG: My career path is uncommon: after obtaining a scientific baccalaureate in France, I joined for three years the Compagnons du Tour de France*. There I followed a work-study training in the timber industry, and obtained a BTS (NDLR: Brevet Technicien Supérieur). At that time, my goal was not so much to obtain a diploma, but rather to immerse myself in the industry to get to know all its workings. These three years allowed me to acquire a very technical training in the field of construction and the wood industry. Then, I passed a competition exam to integrate the ENSTIB School (École Nationale Supérieure des Technologies et Industries du Bois). I graduated three years later in 2016 with an engineering degree.

* The Compagnons du Tour de France offer training in the building and furniture trades, in work-study or continuing education programs.

VP: Can you explain how and why you decided to start a PhD at IBOIS? How did you choose your thesis topic?

JG: at the end of my master's degree at ENSTIB, I did a master project in a start-up company. This project was my first contact with research in timber construction. I enjoyed it, and decided to start a PhD. The IBOIS laboratory is well known at ENSTIB, and has been the seat of several PhDs of former students of my school, so it was quite natural for me to come to IBOIS. When I arrived, the research line of the laboratory was very focused on wood-wood connections, and I was able to contribute to different projects, such as the Théâtre de Vidy. (Editor's note: inaugurated in September 2017). At that time, the question of free-form structures with integrated connections was already widely studied at IBOIS.
On the other hand, I wanted to develop a standardized and optimized construction system for the implementation of more usual constructions. Finally, my thesis topic reflects my passion for the transition from theoretical research to the realization of concrete and operational construction, with the ubiquitous question of sustainability and optimization of resources.

VP: At the beginning of your PhD, what was the focus of your research? What were the main challenges? Did these challenges evolve throughout the 4 years of your PhD?

JG: When I arrived at IBOIS, the challenge was to prove that it was possible to build a building, using only wood-wood connections. The realization of the Vidy Pavilion generated a new challenge: how to give tools to professionals of the timber construction, to enable them to build standard structures entirely out of wood. This new issue implied moving away from complex calculation methods (such as finite elements) to develop efficient calculation methods applicable to standard wooden constructive elements (walls, slabs etc), made with wood-wood connections. How to propose a new construction method easily applicable in the industry, using a fully automated workflow ?

VP: What have been your main accomplishments over the last few years? What were the decisive elements in your research ?

JG: In order to propose a simple and standardized construction system, it was necessary to simplify the joints as much as possible, optimize the assembly steps and propose standardized elements, that are as close as possible to conventional engineering elements. The choice of materials was also important; we focused on the engineered wood panels (type LVL, OSB, CLT) widely used in construction. We then established a methodology to characterize and test the different types of connections: nearly 600 to 700 different joints have been tested! Thanks to these tests, the results allowed us to create and enrich a first database. This database describes the behaviour of joints and architectural elements, which is essential for engineers. If other engineers wish to look into the matter, my publications and results are freely available (open-access) and the database is waiting to be enriched (with, for example, tests on other types of wood materials)! Nowadays, I think it is very important to share research. This new knowledge, created in our research institutes, should be spread worldwide to allow others to contribute.
A decisive factor has been the people who have surrounded me and collaborated with me during these 4 years of research. I take this opportunity to thank them again. It is important to be able to exchange and take a step back: even if you are focused on your subject, exchange remains essential.

VP: In your opinion, has the accomplishment of a PhD (4 years of research) affected your way of thinking and working?

JG: The PhD allows you to build a critical mind. In the first year, a study plan is drawn up and the following years are planned as well as possible. But research is often (always!) full of surprises and you have to be reactive, agile and adaptable. Finally, you are quite aware that the initial plan will not be followed to the letter. But we learn to forge a working method and scientific rigour to advance and meet the challenges of our thesis subject. It is a very formative experience in project management because you have to know how to manage the available resources (budget, personnel, infrastructure, etc.) within a given time frame, which may seem long … but in the end goes by very quickly.
The question of communication is also a big point. How do you present your work, what question do you ask… You have to be able to explain the reasons and the context, and then answer it clearly and in detail according to the audience you have in front of you.

VP: Let's talk about your research topic: what could be the impact of your research for the world of wood construction?

JG: Generally speaking, the construction sector has a very high degree of inertia. That means that everything moves very slowly. However, the world of timber construction has rather always been quite in advance: the timber industry has efficient tools such as CNC cutting machine, and valuable know-how. For us researchers, the challenge is to offer companies new tools that they can already implement in their working methods.
For many years, I have had this desire to participate in the development of more sustainable construction methods. I believe that this research work in connection with industrialists and their digital tools is a gateway to the optimization and sustainability of the timber construction industry. And this is what is happening right now, because industry is not necessarily waiting for research!

VP: What are your professional aspirations, now that you are successfully done with your Ph.D.?

JG: When you do a thesis, you don't necessarily think about the "after" because you have a tight and stressful schedule with deadlines for the next 4 years. However, I want to contribute to the improvement of the society in which we live and of the industry, but I'm not yet sure of the form of my involvement. I wish to make my contribution and especially to see things happen. They are many different opportunities for it to happen; for now, I am continuing my research as a post-doctoral researcher at IBOIS.