竹原 幸生

A213 衝撃力によるモルタル・花崗岩のクラック伝播現象の可視化とPIV解析

The purpose of this research is to explore the mechanism required for the generation of earthquake vibration on the propagation velocity of the crack in fault plane. In this research, the impact splitting tensile tests of mortar and granite were carried out, and the propagation velocity of the crack was visualized and obtained by image analysis using ultra high-speed video camera. A relationship between the impulse which is impact loading and propagation velocity of the crack was observed. There appears to be a critical state in which propagation velocity does not increase, even if impulse is increased over it. It was proven to converge in 2.6 km/sec. Next, the mechanism of the development of the dynamics of the crack by the impulse was examined from displacement vector and Particle Image Velocimetry (PIV) analysis.

222 3板式高速カラービデオ/トリプルフレーミングカメラの性能評価

In 1991, the authors developed a high-speed video camera with a frame rate of 4, 500 pps, which was the worlds fastest at that time and currently marketed by a third party. An MCP-type image intensifier is attached directly to the image sensor to realize both very high light sensitivity and frame rate. Three intensified image sensors are combined with a cubic three-way beam splitter prism and three optical filter holders to form this high speed colour video/ultra-high-speed triple-framing camera.

B209 3板式高速カラービデオ/マルチフレーミングカメラ

Three sets of the intensified image sensors are combined together with a cubic three-way beam-split prism and three optical filter holders to set up a utility high-speed video/ultra-high-speed multi-framing camera. The camera can capture fast-moving images in the following conditions: (1)4, 500-pps continuous color imaging with R, G and B filters and perfect synchronization of three imagers for a full frame of 256x256x3 pixels, and faster color imaging up to 40, 500 pps for reduced resolution of 64x64x3 pixels, (2)Three times faster continuous monochrome imaging without filters and delayed synchronization, i.e., 13, 500-pps for a full frame(256x256), and up to 121, 500-pps for a reduced frame(64x64), and, (3)Ultra-fast three-frame capturing at a rate of 1/10, 000, 000 second by delayed gating of the image intensifiers.