Numerical study of 3D-compressions of entangled materials

We employ a discrete simulation adapted from molecular dynamics techniques in order to study the mechanics of entangled semiflexible fibers. Each fiber is discretized by a small number of segments allowed to stretch and bend. A few hundred fibers, initially straight and placed and oriented at random are simulated during incremental compressions in the three directions of space. Aspect ratios ranging from 20 to 200 were considered. The most important results are (i) an exponent of three is obtained for the pressure–density compression curve, (ii) friction shifts the densities to lower values and (iii) friction does not influence the exponent of the pressure–density curve.