For the designing of the musical instrument material substitutes, the vibration properties, specific dynamic modulus and logarithmic decrement of some wooden musical instrument materials are measured by the vibration testing system.The vibration properties of wooden musical instrument materials are compared with those of wooden generalpurpose materials. Generally various acoustic properties can be calculated from the above parameters. It is found that the musical instrument materials had higher dynamic moduli and lower logarithmic decrements than the wooden generalpurpose materials. From the testing results of unidirectional CFRP and GFRP, it is also found that these materials can't have the same properties as the musical instrument material substitutes. Because it is impossible to design musical instrument material substitutes by only FRP, we fabricate two types of adhesive structures and investigate these vibration properties. One is the 2-layered structure, CFRP/EVA foam. The other is the sandwich structure, FRP/Balsa/FRP. It is confirmed that vibration properties can be controlled by changing the EVA foam position. Two types of the sandwich structures, CFRP/Balsa/CFRP and GFRP/Balsa/GFRP are proposed. In these structures, the skin/core thickness ratio has a great influence on the vibration properties. By controlling the thickness ratio, it is confirmed that the GFRP/Balsa/GFRP can have the same vibration properties as the musical instrument materials. These results indicate .that the 2-layered structure and the sandwich structure using FRP are effective for designing musical instrument material substitutes.

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Conventional reinforcement materials of embankments had only a reinforcement function. However, geocomposite materials that can be used also as the drainage and consolidation materials as well as reinforcement materials are required at present.
In the development of geocomposite drain materials, the choice of filter medium becomes the most important problem, and it is necessary to choice the materials that does not occur the clogging and has the superior permeability in vertical direction. Nonwovens and woven fabrics are used for geosynthetic filter medium widely.
We have cleared the relationship between the pore size and properties of those textiles in first report of a series of studies.
In this paper, we investigate the water permeability of nonwovens and woven fabrics made by varying manufacturingparameters to make use of designing filter medium for geocomposite drain materials with drainage and reinforcement effects.

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