[No. 123] Yoshiteru Aoyagi

When I was in high school, the internet was not as widespread as it is today, so there were very few opportunities to hear the unfiltered voices of university alumni. Now, we can access a wide variety of information in real time, and I feel the world has become a much more convenient place. The content I've written for this article is based on my experiences from over a decade ago, so you could say the information has been well-aged. It's written in a casual tone, so I would appreciate it if you would read it with an open mind.

In high school, I was a typical science-track student, good only at mathematics and physics. I loved what are commonly referred to as "machines," like those in crafts and robotics, so I enrolled in the Department of Mechanical Engineering without a second thought. It was in my sophomore year of university that I realized, "This isn't what I expected." As I studied the four major mechanics that form the foundation of mechanical engineering—mechanical dynamics, materials mechanics, fluid dynamics, and thermodynamics—I discovered that the "kikai" (機械) I was studying was not about "machines" but "mechanics." Still, learning that cars and aircraft are designed and manufactured through the accumulation of this specialized knowledge ignited a desire in me to master these academic fields, even if just a little.

I knocked on the door of the laboratory of Professor Kazuyuki Shizawa (then an associate professor), which focused on solid mechanics, a field that was not very familiar at the time. My reason for choosing it was similar to my motivation for joining the department: I was good at materials mechanics. Another appeal was that it was one of the rare labs in the Department of Mechanical Engineering that didn't conduct experiments. It wasn't that I disliked experiments, but I felt that the approach of tackling unsolved problems using theory and computers was a good fit for me back then. The research topic I was assigned as a fourth-year undergraduate was "Crystal Plasticity Model Using a Differential Geometric Representation of Dislocation Fields and Its Large Deformation FEM Analysis." I didn't understand it at all at first, but 15 years later, I am still conducting research in the same field.

There were no strict rules, and it was a relatively free-spirited laboratory, so for me, the lab felt like a "clubhouse." Whenever I dropped by, my friends, upperclassmen, and underclassmen were there. We would eat meals, chat about the previous night's get-together, play futsal, occasionally talk with our professor, and dedicate ourselves to research... I have nothing but happy memories. I couldn't imagine giving up such an enjoyable life, so I decided to advance to the Doctoral Programs (though that wasn't the only reason, of course).

The Doctoral Programs, unlike the master's program, marked the beginning of rigorous training to become an independent researcher. As opportunities to attend academic conferences grew, I started traveling not only domestically but also to various locations abroad. I had never traveled overseas and could barely speak English, so the thought of presenting at an international conference was incredibly nerve-wracking—I even contemplated fleeing. However, thanks to the generous support of Professor Shizawa, I managed to deliver my presentation. I am still grateful to him today. With more experience, even I got used to it and started to enjoy my international business trips. The thrill of visiting a new place, meeting new people, and experiencing new things was unlike anything I had known before. Although there were hardships, such as pulling all-nighters for research, it was, on the whole, an incredibly rewarding experience.

After completing the Doctoral Programs and following a few twists and turns, I am now an associate professor in the Department of Nanomechanics, Graduate School of Engineering, at Tohoku University, where I stand at the lectern to teach and supervise students in the laboratory. The materials indispensable to our daily lives—metals like iron, steel, and aluminum, and polymer materials such as plastics, fibers, and rubber—are continuously evolving. My research aims to uncover the complex behaviors of these state-of-the-art materials by integrating experimental data with computational simulations to generate new insights. I hope to draw on my experiences to create a bright and enjoyable environment for research.