In modem technology, more widely are used the composites with the gas phase - porous structures with pores closed, filled the gas. Can find here polymeric materials: EPP polyurethanes used in automobile bumpers, CELLASTO polyurethane in suspension systems. To the same group may also include gazars - composites reinforced by gas, and thus structure, in which the gas in the closed pores is subjected to initial pressure. Gazars are made as the structure of metal, usually copper, carbon dioxide or a mixture of gases. The aim of this work is to develop methods of describing the properties of such materials based on knowledge of: basic materials, technologies (gas pressure formed during foaming) using the theory of hyperplastic materials, in particular using Ogden’s model and its modifications. The resulting description can be used for the applicability of hyperelstic models, and therefore in the whole range of deformation of the polymer-based composites and elastic composites of metals (not included plasticity). Verification of the method is carried out through the execution of experimental EPP foam polyurethane derived from car bumpers, enabling a better understanding of materials and will be able to better modify structures, and thus, improve the mechanical properties.