Author(s): Lucas Moreau, Sofia Rinaldi, Markus Vogel and Elena Papadopoulou

Abstract: Granular materials such as sands, gravels, powders, and industrial particulates exhibit complex mechanical responses when subjected to repeated loading. Under low-amplitude cyclic loading, these materials often remain below classical failure thresholds, yet they undergo progressive microstructural rearrangements that significantly influence stiffness, damping, and long-term stability. This study examines the mechanical behavior of granular assemblies exposed to low-amplitude cyclic loading, with emphasis on strain accumulation, modulus evolution, and energy dissipation mechanisms. The abstract synthesizes experimental observations from cyclic triaxial, resonant column, and simple shear tests, alongside insights from micromechanical interpretations. Results reported in the literature consistently demonstrate that even small cyclic stresses can induce irreversible particle rearrangement, contact sliding, and fabric anisotropy development. These processes lead to phenomena such as cyclic hardening or softening, depending on initial density, confining pressure, particle shape, and loading frequency. Particular attention is given to the threshold strain concept, below which granular materials exhibit quasi-elastic behavior and above which plastic deformation accumulates. The role of coordination number evolution and contact force redistribution in governing small-strain stiffness is also highlighted. Understanding these mechanisms is critical for predicting the performance of geotechnical systems subjected to environmental vibrations, traffic loads, and seismic aftershocks, where cyclic stresses are typically low but persistent. The findings summarized in this work contribute to improved constitutive modeling of granular materials by linking macroscopic response to microscopic mechanisms under cyclic loading. Such understanding supports safer and more economical design of foundations, pavements, embankments, and granular layers in engineering practice, particularly in applications where serviceability rather than ultimate failure governs performance.

DOI: 10.22271/2707806X.2026.v7.i1a.54

Pages: 11-15 | Views: 31 | Downloads: 8

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