Abstract A simple model is proposed which qualitatively describes the phenomenon of the dynamic loading of a fibrous material. The model is based on a treatment of the laws of conservation of energy and momentum during the fragmentation of a material. A dependence of the sizes of the fragments on their shapes, rates of deformation, densities and energies of formation of new surfaces is introduced. By fragments, we mean those parts of bodies which have been formed during the break up of the latter. The fibre fragments of a composite are called splinters. A comparison is made with experimental data.