抄録
In this study authors measure both of the maximum coefficients of static friction while a vibration board vibrates and it doesn't, and examine the effect of decrease of friction by vibration. In this case, four kinds of small metal blocks instead of powder and grains are used because the study is fundamental research. As a result it is found that the maximum coefficient of static friction decreases with increasing the amplitude, and finally settles down about constant value. And also, the same tendency and the rate of decrease for these metal blocks can be seen.
