ON THE DESCRIPTION OF THE PHENOMENON OF FILLED ELASTOMER STRENGTHENINGYu. A. Gamlitskii and Yu. P. Bass UDC 678.01:539.21 Relations invariantly relating the matrix deformation to the composite deformation have been derived. A model that permits obtaining a Mullins effect and explains the multiple increase in the strength characteristics of the composite compared to the matrix is proposed. At the basis of the model is the presence at the matrix-filler boundary of a hard rubber layer. This layer is formed due to the interaction between the active surface of the filler and the rubber macromolecules. The quantitative form of the tension distribution function density of active chains of the mesh explaining the strengthening phenomenon has been substantiated. Federal State Unitary Enterprise "Scientific-Research Institute of Tire Industry," Moscow; email: firstname.lastname@example.org. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 76, No. 3, pp. 101-105, May-June, 2003. Original article submitted September 6, 2002.