Tsutomu Yoshida

Research on relation between bending stress and characteristic frequency of H-shaped beam by free vibration deflection

In order to investigate a relation between a bending stress and a characteristic frequency of a beam, 4-point loading which had constant moment region was conducted to a beam with H shape configuration experimentally and numerically. H-shaped beam has many characteristic deformation modes. Axial tensile stress in the beam made its characteristic frequency higher, and compressive stress lower. In the experiment, some characteristic frequencies got higher by a bending stress, and the others stayed in a small frequency fluctuation. The distinction is anticipated as a capability to measure a bending stress of a beam by its characteristic frequencies.

Measurement of Elastic Constants for Composite Materials by 3-Point Bending, Twisting and Impact Sound Test

Analyzing a sound produced by an impact of a fallen ball upon a small rectangular bar specimen, elastic moduli of engineering ceramic composites can be determined. In this paper,three-points bending and torsional test devices which employed the specimen for the impactsound test were designed. Using the devices, elastic moduli of various materials were mea-sured applying deformation theory. The elastic constants evaluated by the impact sound testwere compared with those measured by the devices. They agreed well. A reliable measure-ment system was developed for elastic constants of anisotropic materials.