Inverted triangular self stressing roof truss - has horizontal member connected to sloping members by vertical struts to concel bending and tensile stresses

摘要

An inverted self-stressing roof truss shaped like a triangle with the point facing downwards, is intended to transfer pull, not to the centre of gravity of the section of the tie beam, but instead to offset the point of application of the pull. It is in two halves (2, 3) anchored at each end to a horizontal beam (1) with vertical props (5) joining them at regular intervals the whole length of the truss. One central prop (4) is attached to the top part of the two truss sections. The props transfer the exterior vertical loads applied to the beam (1) onto the truss. This is then subjected to bending stress between the anchorage and the point of the triangle, and also to pull because the truss also acts as the tie beam in the stability of the system. It is possible to calculate dimensions so that the dual effect of bending stress and pull cancel each other out.