Estimation method for shock absorbability and walking performance of wood based floors.

Research Project

Project/Area Number	61560192
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	林産学
Research Institution	Kyoto University
Principal Investigator	MASUDA Minoru Kyoto University, Associate Professor, 農学部, 助教授 (40027165)
Co-Investigator(Kenkyū-buntansha)	SADOH Takeshi Kyoto University, Professor, 農学部, 教授 (00026494)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥2,200,000 (Direct Cost: ¥2,200,000) Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	Impact / Shock absorbability / Walking performance / Wood based floor / Coefficient of restitution / Steel cylinder impression hardness / 熱流量 / 衝撃ひずみ / 衝撃たわみ / 表面硬さ / 衝撃加速度 / 床剛性
Research Abstract	1. How much strong force exerts when a body falls on a floor? It should be determined by mechanical properties of the falling body and the floor. A theoretical equation which predicts impact force was derived in this study, and good agreement with the theoretical forces and experimental ones was obtained. 2. It was investigated that what kind of mechanical properties of floors and falling bodies mainly decides coefficient of restitution. And it was discovered that a hysteresis loop of load-deformation curve of the falling body and the floor gives decisive effect on the coefficient. A theoretical equation for estimating the coefficient of restitution was derived and good agreement was observed between theoretical values and experimental ones. But in several cases of combination of floors and falling bodies, the theoretical equation gives higher value than observed coefficient. This may have something to do with difference of vibration frequencies of the falling body and the floor. 3. Questionnaires were distributed regarding psychological images of floors made of plywood,particleboard, concrete, ALC,carpet, Tatami-mat, vinyl chloride foam mat(cushion floor) or P-tile. Images of "hardness" has correlation between steel cylinder impress hardness which was developed in this study. "Cool" impage has high correlation between logarithm of heat flow from foot to floor. Coefficient of restitution has no high correlation between image of walking performance. "Warmness" and "softness" has high correlation between walking performance, so that "steel cylinder impression hardness" and "heat flow" from foot have also high correlation.