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In general, eigenvalue analysis for beams considering rotatory inertia and shear deformation is not trivial, even in the case of uniform beams. In this paper, a practical method is proposed for calculating natural bending frequencies of uniform elastic beams considering rotatory inertia and shear deformation. The proposed method is based on the modified Timoshenko beam theory, which is more rigorous and realistic than the traditional Timoshenko beam theory. It is shown that the proposed method calculates the natural frequencies of an arbitrary order-vibration mode for beams of arbitrary cross-sections with a high level of accuracy, similar to numerical analysis.

An automated warehouse is a system which automatically controls the storing and shipping of a large number of cargoes in small floor spaces. In the 2011 Tohoku earthquake, many automated warehouses shut down because of the fall of stacked cargoes, and the recovery needs a long time. The importance of the seismic countermeasure preventing the fall of cargoes is noticed from the business continuity planning. The authors developed two countermeasures; one is the vibration control system and the other is the base isolation system. For developing these countermeasures, it is important to clarify the falling behaviors of cargoes. Shaking table tests were conducted for evaluating them. This paper describes the experimental results focusing on the dynamic characteristics of cargoes.

This report shows the advantage of using high-strength steels and hysteretic dampers for low- and medium-rise buildings. In this paper, the structural members are decided by the long term stress. Seismic loads are burdened with hysteretic dampers. There are two methods to increase the yield stress of columns; one is using high-strength steels, and the other is adopting larger members. Through the investigation of time history response analysis, a method using high-strength steels has high performance not only decreasing damage of frame but also increasing the equivalent damping factor than another method.

This paper discusses the wind tunnel tests for a tall building model having either viscous or visco-elastic damper under the turbulent boundary layer flow. The wind tunnel tests are carried out either the across- or along-wind direction for the viscous and the visco-elastic damper systems, respectively. This wind test set-up includes a special measurement system to obtain the damper hysteetic loop, then the response property of damper and system are discussed by the referring to the obtained loop. In case of the severe wind speed, the response of visco-elastic system is smaller than the viscous system because the stiffness of visco-elastic damper contributes to the stiffness of system.