Fluidity characteristic of granular materials within low frequency dynamics. (15th July 2021)

• Record Type: Journal Article
• Authors: Tong, L.H.; Qi, Bowen; Xu, Changjie
• Is Part Of: International journal of mechanical sciences. Volume 202/203(2021)
• Publication Date: 2021-07-15
• Subjects: Granular materials -- Dynamics -- Fluidity -- Viscosity -- Triaxial tests; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2021.106508
• Languages: English
• ISSNs: 0020-7403

Abstract

Highlights: We study rheological behaviors of granular materials undergoing low-frequency dynamical loading. Strain evolution experiments show that fluidity of granular material is enhanced with vibration amplitude and frequency. Dynamic weakening of effective viscosity of granular materials can be elucidated theoretically by our proposed statistical model. Abstract: Dynamic fluidization behavior has been generally identified as a result of irreversible grain sliding and dominates the strain time evolution in granular materials in presence of vibrations. From vibration-induced strain evolution experiments performed in a triaxial configuration, we provide direct evidences that fluidity of granular packing is enhanced with vibration amplitude and frequency within low frequency dynamics. It is verified that a simple fluidity model based on standard Maxwell viscoelastic rheology can be used to account for the strain time evolution in presence of low frequency vibrations. The proposed configuration reveals that the frequency has a completely contrary effect on aging and rejuvenation of the granular system comparing with vibration amplitude. Weakening of effective viscosity induced by increasing vibration amplitude and frequency is well elucidated by a statistical model, in which both parameters considering potential energy stored in the system and distribution of grain-contact orientations are introduced. Graphical abstract: Typical input dynamic load with frequency of 1 Hz and the observed strain evolution using a triaxial test system. Image, graphical abstract