Approximate Analysis of Space Trusses

Abstract

For decades, space trusses have been designed using approximate numerical methods that are based on simplified truss layouts. Although these methods still rely on using computers, their demand on computer time and resources is considerably less than that associated with full finite element analyses. However, as the last decade has seen a revolutionary advance in computer technology, full F.E. analyses are no longer time consuming or expensive, and as a consequence, the old approximate analysis methods have become almost obsolete. Now the need has shifted towards methods that are quick and easy to use, and yet accurate enough for preliminary designs and as a check on F.E. analysis results. In practice, a suitable method is adopted for a first choice of member sizes, then the results obtained are fed into a cycle or more of F.E. analysis and redesign until a final design is reached. Following a discussion on the required characteristics of modem approximate methods of space truss analysis, two examples of these methods are presented and assessed in this paper.