On the basis of experimental data from the piano hammers study a one-dimensional constitutive equation of wool felt material is proposed and used to study compression pulse propagation in microstructured felt. One-dimensional strain wave propagation in wool felt is considered. It is revealed that stiffness of microstructured wool felt is a nonlinear function of the felt compression, and it is strongly determined by the rate of the felt loading. This means that the speed of the compression wave that propagates in such medium depends on the form of the wave and its amplitude. It is shown that a pulse of a smooth form that has no discontinuity on its front propagates with a constant speed up to the moment when the accumulation of nonlinear effects results in the eventual continuous wave breaking. After that moment, a shock wave will be formed, and the velocity of the shock wave propagation depends on the value of its amplitude jump discontinuity across the wave front. It is shown that the front velocity of the shock wave is greater than the velocity of sound in a linear medium.
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