Investigation of physically nonlinear behaviour of polystyrene packages and their elements


  • K. Ragulskis
  • E. Kibirkštis
  • A. Dabkevičius
  • V. Bivainis
  • V. Miliūnas
  • L. Ragulskis


The model for the analysis of compression of a polystyrene package is based on the analysis of an axi-symmetric physically nonlinear elastic structure. Nonlinear elasticity is taken into account using the hyperbolic model and it is considered as an approximation to the plastic be-haviour which can be analyzed by the theory of deforma-tional plasticity valid for monotonic loading.
The model for the analysis of bending of a strip of polystyrene is presented. The beam model by taking cubic nonlinearity of Duffing type into account is used. It is shown that the bending behaviour is substantially influ-enced by the physical nonlinearity.
Experimental investigations using a specially de-veloped setup have been performed for a number of types of polystyrene packages. The main graphical relationships and results of the experimental investigations are pre-sented. It is determined that the results of experimental investigations in the initial stage of deformations corre-spond with the numerical ones. The obtained results of investigations are used in the process of design of the ele-ments of packages.