| 摘要 |
A structural element (1, 20, 30, 40) comprises a web (2) extending between a pair of flanges (3, 4). The areas of particular structural importance are the portions (5, 6) of theweb and flanges adjacent to the junction between the web and the flanges. Material is gathered into these structurally important areas of an otherwise thin component. This is achieved by providing a plurality of small ribs (10) to absorb the material in these structurally important areas (5, 6). The ribs (10) are on a pitch of 2 to 8 times the wall thickness t. The pitch is approximately the same as a typical self drilling, self tapping fastener to prevent skating of the fastener, on fixing. The ribs (10) are of a depth of between 1.5t and 3.0t, where t is the metal thickness. These parameters ensure that in terms of fixing, the ribs allow a fastening screw to be used and to perform in the same manner as with a flat faced flange or web. |
