Mechanics of building structures

Mechanics of Building Structures

Kyoto University

Research Topics

1. Optimal design of building structures taking practical conditions into consideration

The performance requirements of building structures are getting more complex, diverse, and sophisticated. Further, it is strongly required to reduce the consumption of natural resources and the construction cost. To provide clear and effective solutions to such problems, it is strongly needed to improve the current status of structural design that depends on the intuition and experience of structural designers and to advance its restructure by appropriately introducing logical methods.

In practical design, design solutions are never accepted unless all the conditions are taken into account. For this purpose, we perform optimal design taking all the practical conditions into consideration. To deal with practical conditions, we propose a structural design navigation system, in which constraint conditions and objective functions can be set and changed at an arbitrary stage of the design process and the effect of change in a design condition on the other performance and cost is provided.

2. Interactive design method for membrane structures

Since architecture forms a living space for human, many factors like sensitivity and value, which are difficult to express numerically, interact in design (beauty of shapes and allocation of rooms are typical examples).

These factors change drastically in relation to cost and functionality. It is necessary to accept such characteristics inherent in architecture and to construct a new design system that effectively organizes human, theory, and information. For instance, complex structural analysis and sensual shape design are needed in the design of membrane structures. To such design, we propose an interactive design method, in which decision is made by directly controlling performance.

3.Unstable phenomena and limit state conditions for elastoplastic structures

For more sound structural design, it is important to understand the structural response under external disturbances like earthquakes and strong winds as accurate as possible and to set up proper critical conditions for avoiding undesirable response like unstable phenomena. Toward these goals, our comprehensive research ranges from developing fundamental theories and numerical techniques in structural mechanics to proposing practical design conditions for building structures.

A comprehensive stability design method for member and total buckling
Collapse behavior and stability limit of building structures under strong earthquakes
Unstable phenomena and limit state condition for elastoplastic structures under cyclic loading (symmetry limit theory and steady-state limit theory)
Stability of materials and structures based on fracture mechanics and crystal plasticity

4. Structural analysis methods and computational solid mechanics

To simulate the process of collapse of a structure and its limit states, a highly sophisticated simulation technique is needed. Toward this end, we develop fundamental theories for numerical modeling, implement the developed theory, and perform simulations for a variety of structural systems. Experimental studies are also conducted to validate the theoretical predictions by comparing them with the physical response.

Numerical methods for simulating critical phenomena of structures taking material and geometric nonlinearity into account
Dynamic response analysis of building structures with member fracture
Theories and techniques for large-scale simulations
Experiments and numerical modeling of traditional timber structures
Numerical methods for more efficient and stable dynamic analysis of structures having contact constraints
Eigenvalue analysis of piezoelectric plates by the time-harmonic boundary element method (BEM)

5. Nondestructive testing of structural systems

It is recognized that the structural integrity of infrastructures degrades quite rapidly in the near future in developed countries including Japan. Further, Japan is known as a country prone to natural disasters, e.g., earthquakes. Hence, it is one of the most important research topics to prolong the life span of building infrastructures while keeping their safety against natural disasters. For these purposes, our research aims at developing practical damage detection schemes for building structures from their measured response based on system identification techniques.

Optimal sensor placement and loading conditions for system identification
Experimental study for validating the proposed methods
Extension and improvement of damage-detection codes for practical structural