CHAPTER XIX – TAPERED STRUTS

Publisher Summary This chapter discusses tapered struts. In a pin-jointed strut failure always occurs on account of the stress exceeding a certain limit, at least in all the struts that are ever used in engineering or building, on account of a real or fictitious eccentricity, although it happens that if the ratio l/k exceed a certain value, and eccentricity of loading be small, the strength may be calculated from the criterion of stability without appreciable error. If the section of the strut be uniform, the stress will be greatest on the central cross section. In view of this it appears that we could obtain a more economical strut by designing it so that the maximum stress on all sections is the same, by tapering the strut towards the ends. Such a strut will be called a strut of uniform stress. Tapered struts are sometimes made with their longitudinal section in the form of an ellipse with its ends cut off. This is a bad type of strut as, even with “long” struts, stress failure will probably occur near the ends before the Euler crippling load is reached. The most simple kind of tapered strut is one in which the longitudinal section consists of a central parallel portion and two conical ends.