About MIST

The Mitsui Institute of Structural Technology (MIST) of the Department of Architecture and Building Engineering of the Institute of Science Tokyo was founded in Dec., 2024. The activity is based on tests on building materials and structures, both for scientific purposes.

The laboratory is equipped with a large frames, it allows to perform experimental activities on large-scale models, even in 1:1 scale. This configuration gives the Laboratory a specific versatility for carrying out seismic tests.

Our laboratory focuses on understanding and evaluating the behavior and performance of steel structures, ranging from material properties to structural members and connections. Most of our research activities are conducted in collaboration with the Ikarashi Laboratory.

While steel structures remain our primary field of interest, we have recently expanded our research into related areas, including CLT panels, RC slabs, and innovative structural systems utilizing adhesives.

To address these challenges, we combine experimental and analytical approaches. Full-scale and laboratory experiments are performed to capture actual structural behavior, while finite element analysis and theoretical modeling are employed to gain deeper insight into structural mechanisms and develop practical design methodologies.

 The research activity of the MIST is primarily devoted to the experimental study of the seismic behaviour exhibited by ordinary and steel structures. A further field of numerical analysis investigation concerns the behaviour of buckling behavior. Focusing on the use of new materials in the field of Architectural and Civil Engineering, a remarkable part of the Laboratory's activity is also dedicated to experiments on the related structural connections, both bolted and glued. A further research topic concerns the development of software for buckling behavior of I-shaped beams and thin-walled members. 

Structural design has traditionally been required to protect human life and property during major earthquakes while also enabling open and lightweight architectural spaces. However, as societal needs continue to evolve, I believe that sustainability and environmental responsibility will become increasingly important requirements in structural design.

Steel structures are buildings whose primary structural members are made of steel. However, the production of steel generates a significant amount of carbon dioxide. Specifically, approximately two tons of CO₂ are emitted for every ton of steel produced. Therefore, environmental issues are not something that those of us involved in the construction industry can ignore.

On the other hand, for countries such as Japan, which frequently experience natural disasters and require the construction of high-rise buildings, steel remains an irreplaceable material due to its high strength and excellent ductility. In many applications, it cannot simply be replaced by timber or concrete.

How, then, can we design steel structures that are both safe and environmentally responsible? One possible answer is to reduce the amount of steel used by optimizing the cross-sectional shapes of structural members while maintaining thinner plate thicknesses. By improving structural efficiency through innovative cross-sectional design, we aim to reduce material consumption while maintaining the same level of structural performance as conventional steel structures. Through this approach, our research seeks to contribute both to structural safety and to environmental sustainability.

Understanding the overall behavior of a structure is essential for structural design. However, global structural behavior is governed by the behavior of individual members, and accurate prediction of member behavior is therefore crucial for understanding the performance of the entire structure. Furthermore, member behavior, particularly phenomena such as buckling and fracture, is strongly influenced by material properties.

In other words, materials, structural members, and global structural behavior are all interconnected. I believe that these topics should not be studied independently but rather through an integrated research approach. At the Mitsui Laboratory, we conduct research spanning all scales, from material behavior and member performance to the response of entire structural systems.

What Is Buckling?

To create lightweight architectural spaces and reduce material consumption, engineers often use thin-walled or slender structural members. However, such members are susceptible to buckling, one of the most important phenomena in structural engineering.

Although steel is a very strong construction material, structural members subjected to compressive forces may experience buckling and fail at loads significantly lower than those expected under tension. Understanding and preventing buckling is therefore essential for the safe and efficient design of structures.

One fascinating aspect of buckling is that it is a natural phenomenon that can be explained through mathematics. Nature and mathematics are closely connected; a famous example is the relationship between the Fibonacci sequence and the arrangement of sunflower seeds. In a similar way, studying buckling means exploring the mathematical principles behind a natural phenomenon.

Because of this, research on buckling often feels like solving a mathematical puzzle. Personally, I would not describe myself as a mathematician, but I believe that anyone with curiosity and a desire to explore can become a little bit of a mathematician—or even a physicist—through structural engineering research.

• Apr 2026 Our Instagram post exceeded 7,000 likes.

• Apr 2026 A laboratory information session will be held after the graduate school admission briefing on May 16.

• Apr 2026 A new fourth-year student has been assigned!

• Feb 2026 The structural performance index WFp, developed through our research, was implemented in the structural analysis program RESP.

• Dec 2025　The undergraduate thesis presentation

• May 2025　Overview Document of the Laboratory (Prepared by Mitsuda and Okazaki)

• Apr 2025  Prof. Mitsui received the AIJ Young Research Award in 2025.

• Apr 2025 Two undergraduate students were assigned to Mitsui laboratory. (Keigo Okazaki, Sena Mitsuda)

• Mar 2025  Prof. Mitsui participated as a panelist in the SSI Workshop, "Building a Sustainable Society through Next-Generation AI Utilization."

• Dec 2024 Republic of Tunisia Ambassador visits our structural lab.

• Dec 2024  Mitsui Labs. was established.