A NEW APPROACH TO GEOMETRIC NONLINEARITY OF CABLE STRUCTURES

The basic structural principles surrounding nonlinear behaviour of cab le networks are explained through the example of a two-link structure. The nonlinear static response to load for this structure is then deri ved explicitly using the proposed simple approach, and results are com pared with those obtained from a general two-dimensional non-linear ba r element (derivation given), and to results quoted in the literature. The proposed approach to geometric nonlinearity is then tested on thr ee three-dimensional cable networks and the results compared with thos e obtained by three other techniques, namely geometric stiffness matri x, dynamic relaxation and general minimum energy. The proposed techniq ue has been found to be comparable to established techniques in accura cy, stability and speed of solution while at the same time exhibiting the key features of separation of the numerical computation from the u nderlying structural mechanics, and the requirement of understanding o nly the most elementary of structural mechanics. The proposed techniqu e is thus also most suitable for introducing cable structures to under graduate courses. (C) 1998 Elsevier Science Ltd. All rights reserved.