| 摘要 |
PURPOSE:To restrict vibration of the duct by a method wherein the plate material of the duct is consisting of a thin dimple plate formed with a plurality of recesses and protrusions, protruded and recessed on both surfaces allover thereof alternately. CONSTITUTION:The walls of the duct 11, having a wind tunnel having rectangular section, or the flange wall 12 and a web wall 13 are connected at respective sections 14 by duplicated interlocking connection and a connecting flange 15 is connected to the opening section of the duct by rivets 16. The plate material a1, constituting the flange wall 12 and the web wall 13, is a thin plate formed with a plurality of protrusions (b) and recesses (c) on both sides of the plate so as to protrude or recess in the semi-circular section alternately in the transverse and lateral directions in the shape of lattices. The sizes of respective protrusions (b) and recesses (c) are made constant and the shaft of gravity center (a neutral shaft) coincides with the central axis (x) of the main part (a'1) of the flat plate material so as to increase the rigidity of the plate. According to such constitution, the vibration of the duct walls may be reduced remarkably. |
