Rearrangement Towards Stability: Plastic Shakedown in Granular Materials Under Thermal Cycles

ABSTRACT Granular materials are routinely subjected to thermal cycling due to natural and anthropogenic phenomena. Despite the ubiquity of this occurrence and its relevance for science, engineering, and technology, the long‐term thermo‐mechanical response of granular materials to repeated heating and cooling remains poorly understood. In this work, we employ large‐scale discrete element simulations to investigate the evolutionary response of granular materials subjected to cyclic thermal loading, with the aim of understanding whether these materials deform indefinitely upon thermal cycling or undergo particle rearrangement towards a stabilized structural state. By considering the response of such materials under isotropic and laterally restrained (oedometric) conditions, the study explores the influence of temperature amplitude, mean effective stress, initial relative density, and material properties like Young's modulus, interparticle friction coefficient, particle thermal expansion coefficient, and particle size distribution. The simulations show that the consideration of a sufficient number of thermal cycles always brings granular materials to a stabilized structural state through plastic shakedown, regardless of their boundary conditions, stress state, or material properties. This evidence suggests that plastic shakedown is a fundamental mechanism governing thermally induced strains in granular materials subjected to cyclic heating and cooling, in much the same way it happens with cyclic mechanical loading.