A STUDY OF COMPARATIVE PERFORMANCE FOR DIFFERENT TYPES OF CABLE TRUSSES

Abstract

During the last two decades there has been a steadily growing interest in the general use of tension structures for large spans. 'There has been an increase in the number of hanging roof structures that have been built. This has led to an increasing amount of theoretical research work devoted to the analysis of tension structures. Cable structures which exhibit non—linear structural response, pose a special problem of analysis. However, with the advent of electronic digital computers, it is now possible to solve complex problems satisfactorily. Analysis methods and computer techniques presently available, enable one to undertake the detailed study of different suspended roof systems. Amongst the various forms of cable roof systems used, the truss form is the most popular, on account of its simplicity and versatility. In the present work an attempt has been made to study the comparative behaviour of different types of cable truss configurations. This, in turn, will help the designer to choose the most economical cable truss form to suit the requirements. The influence of each design . parameter, such as, sag to span ratio, cable sizes and prestressing forces, uponthe behaviour of the structure has been investigated for various cable truss forms subjected to both symmetrical and unsymmetrical loading. The structural efficiency of a truss form with vertical hangers and with the two main cables connected together at the centre span points is established in comparison to other forms. The effect of support flexi-bility has also been studied for some cable truss configurations. Cable trusses have been analysed as a discrete system by means of the displacement method. For the purpose an already available computer programme has' been used after necessary modifications. A subroutine has also been developed to compute the initial geometry of the system for various cable truss forms with vertical