粒状体が作るアーチの安定性と目詰まりの発生の関係について

概要

論文の詳細を見る
Two dimensional physical experiments were performed to find under what conditions the formation of arches plugging the flow is likely to occur, throughout the gravity emptying of a silo. Labolatory measurements of particles' movement with the help of a video camera gave some interesting results; 1) there can be seen two axi-symmetric slip lines during continuous flow of particles, but particles' flow only on a one-side slip line was found at each moment; 2) at transition of the flow from one-side to the other, two-side flows collided each other just above the hopper, which possibly resulted in the formation of arches; 3) in the special case for 2) when arches were stable enough, plugging of the flow occurred. Thus the stability of arches can be the key parameter of the occurrence of plugging. But it is not easy to quantify the stability of arches of granular materials. In this paper we attempt to demonstrate the calculation of the stability of arches using the techniques of structure mechanics. The arches of granular materials were modeled into two hinges arches and intersectional forces were calculated for concentrated load. By comparison with absolute maximum shearing force and the product of axial force and the coefficient of friction of stainless steel, the stability of arches were determined. Therefore it was found that axi-symmetric load on axi-symmetric arches has its great contribution to the strength of arches.
神戸大学の論文
1993-01-30