An experimental study on thickness loss of Wilton type carpets produced with different pile materials after prolonged heavy static loading. Part 2: Energy absorption and hysteresis effect

In the first part of the article, an evaluation was made of the characteristic parameters defined as the squeezing susceptibility or compression sensitivity S, permanent deformation DP, elasticity E and resilience R, all quantities expressed in per cent, which determine the behaviours of carpets of different pile materials (wool acrylic and PP). This second part consists of an extended analysis covering the energy absorption, work done on the carpet, damping characteristics and hysteresis effect of pile materials on the behaviours of carpet during recovery after unloading the static pressure. Therefore, some more definitions are also presented, such as the rigidity coefficient, withdrawal force, total energy, elastic energy, damping energy, elastic recovery coefficient, damping coefficient and decompression coefficient. Throughout the paper, these parameters are specifically symbolised and explained for each carpet, and the results are discussed at the end