Sensitivity of Space Trusses to Member Geometric Imperfections

Abstract

The existence of some geometrically imperfect members in a space truss is almost inevitable, and the fact that they produce initial internal member forces is undeniable. This paper is not about how to avoid member imperfections, but rather is a step forward towards better understanding of the implications of having imperfect members. The paper attempts to answer two main questions; how damaging are member imperfections to truss strength and behaviour; and where are the critical areas of a truss at which no imperfect member should be used? Additionally, the effect of composite action between a top concrete slab and a steel truss in suppressing truss sensitivity is assessed. The work is carried out on a non-composite and a composite square-on-square space truss.