Finite deformation analysis of linearly viscoelastic simple structures2

In order to determine the effect of finite deformations on the stability and non-linear time-deflection behaviour of linearly viscoelastic uniaxially stressed structures, a series of simple rigid-bar-spring dashpot models were analysed ‘exactly’. The material representation was also kept as simple as possible using the standard three-element solid model.Results obtained indicate that the relaxation behaviour of such a structure depends only on its material properties. The creep response is influenced not only by the load level but most significantly by the instantaneous non-linear elastic characteristics of the structure. For structures exhibiting instantaneous elastic local instability a ‘critical time’ may be defined beyond which equilibrium is impossible. The definition for ‘safe-load-limit’ or viscoelastic critical force usually used in linear stability analyses of viscoelastic columns is generalized.