... 17Fig. 2.11 Viscous connec-tions: a cohesive material with rigid particles, b viscoelasticgranular materialFig. 2.12 Plastic connec-tions: a plastic material with rigid particles, belastic-plasticgranular ... (1992)22. Mr z, Z. , Szymanski, C.: Non-associated flow rules in description of plastic flow of granular materials. In: Olszak, W. (ed.) Limit Analysis and Rheological Approach in Soil Mechanics. CISM Courses ... compression. A rigid contact describes mechanical prop-erties of an ideal granular material involving rigid particles for an uniaxial stressstate. Combining it with elastic, plastic, and viscous...