Application of the sub-region mixed energy principle to numerical modelling of prestressed clad cable nets

The sub-region mixed energy principle is applied to the analysis of pre-stressed clad cable net structures, with the emphasis on the interaction between the cable net and the cladding panels. The sub-region mixed energy principle is reformulated with special consideration of the conditions under which the principle is applicable to geometrically non-linear problems. The established governing equations are solved using the dynamic relaxation technique. Comparison of the results from the proposed numerical approach and from an experimental model shows good agreement. Two numerical models, a five-force model and a four-force model, arc developed to represent the behaviour of flat or warped quadrilateral panels. The flexibility matrices of these models are calculated using the finite element method. The influence of curvature of the panels on flexibility, and the influence of different finite element meshes on the results of flexibility analysis are investigated. The five-force model is proved to be capable of expressing any self-balanced nodal forces applied to a panel. Several computer programs for the analysis of clad network structures are introduced. These programs are the result of optimisation of dynamic relaxation, involving viscous and kinetic dampings respectively, and different selections of parameters that control the speed of convergence of the method, mainly the fictitious masses. Numerical examples are calculated and the effects of using these programs on the rate of convergence of the solution are discussed