Plastic Design Aids for Pinned-Base Gabled Frames

Abstract

Single-span rigid steel gabled frames are widely used in the construction of structures covering large areas with no obstructions, such as industrial buildings, auditoriums, warehouses, etc. It is the intent of this paper to facilitate the design of such structures by offering charts for the ultimate strength requirements of the frameworks that comprise them. In the case of statically indeterminate structures, such as most rigid frames, the methods of plastic design are more rational procedures than their elastic counterparts and yield lighter, yet perfectly adequate, designs. Furthermore, it is possible to realize additional weight savings by using haunches at the eaves of the frame, which strengthen the structure, and by using different column and rafter sections that result in a more efficient distribution of material. Only pinned-base frames are investigated, since complete end fixity is not only difficult to achieve in practice, but is also expensive. Besides, in the case of a differential settlement, the results are less detrimental to the frame if the bases of the columns are pinned rather than fixed.