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The Structural Engineer, Volume 62, Issue 14, 1984
The shape of a structure often plays a significant part in deciding its cost. In this paper a method is proposed for the design of pin-jointed space frames which includes the shape, i.e. their geometry and topology, as a variable to be decided not by the designer but by the method itself. The method includes stress, serviceability, buckling and stiffness requirements as constraints to be satisfied, while the cost of the material is minimised. In doing so the self-weight of the structure, which is changing during the design process, is fully considered as a design variable. To reduce cost, members are allowed to be grouped together so that those in a group have the same cross-section. However, a member is allowed to have a variable length as the joints at its end are allowed to move in a 3-dimensional space. Examples are given of the design method which include a dome and a transmission tower. Professor K.I. Majid and X. Tang
In the course of redrafting BS5950, the successor to BS449, it was discovered that the common method of design for single-angle tension members connected by welding at the ends is based entirely on research for such members connected by bolting. A literature search failed to reveal any evidence for the use of the method for welded members and, as a result, a series of tests was carried out at the Polytechnic of Central London. This paper reports on those tests which confirmed the expected conservativeness of the BS449 method and suggests a simpler, less conservative approach. P.E. Regan and P.R. Salter