| 摘要 |
PURPOSE:To make the bending-resistant load larger by a structure wherein stiffeners are equipped on the inside or outside surface, except four corners, in the longitudinal direction of duct plates, on the side of which bending load is applied. CONSTITUTION:T-shape stiffeners 10 are equipped by welding or the like on the inside surface of the upper and lower plank surfaces 1 of a duct in the longitudinal direction at its middle part. Due to the above-mentioned structure, the middle part of a duct plate, the part of which has not contributed to the bending strength at a conventional duct, can be made contribute to the bending strength. Consequently, the strength to bending load of the duct can be heightened. |
