1990 Fiscal Year Final Research Report Summary

Study on Mechanics of a System Consisting of Ski. Bining, Boots and Skier

Research Project

Project/Area Number	02650192
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	機械力学・制御工学
Research Institution	Chubu University
Principal Investigator	SAKATA Toshiyuki Chubu University, College of Engineering, Professor, 工学部, 教授 (80090174)
Project Period (FY)	1990
Keywords	Ski / Distribution of mass / Flexural rigidity / Torsional rigidity / Damping ratio / Natural frequency / Nonhomogeneous beam / Bending vibration
Research Abstract	1. Development of measuring apparatus Apparatuses were developed for measuring rapidly the flexural rigidity and tortional rigidity of a ski. 2. Mechanical properties of a ski Four kinds of ski, of which structure, manufacturing process, material and size are different from each other, were chosen for investigating the distribution of mass of the ski. They were cut into small parts and the mass of each part was measured. Experimental results showed that the ratio of the mass per unit length of each part to the mass per unit length of the ski varies in the similar manner along the longitudinal direction with no relation to the kind of ski. Accordingly, one can estimate simply the mass of each part from the whole mass and length of the ski. Next, the damping ratio and natural frequency of ski were measured by using the experimental modal analysis. Since 43 kinds of ski were measured, it is considered that the damping ratio of the ski sold in markets is roughly made clear in this study. Furthermore, the flexural rigidity and torsional rigidity of each small part were measured. Since the measurement of flexural rigidity and torsional rigidity of small parts was difficult, the distribution of them has not been published at yet. Experimental results obtained in the study are considered to be vary valuable. 3. Research on binding and boots By visiting to the companies of binding and boots, research was carried out on kind, material, mechanical properties, its measuring apparatus and standards of binding and boots. It follows that the releasing property of the binding and the mechanical properties of boots are important for the simulation of skiing.