Development of the Maximum Rate of Dissipation Criterion to Analyze the Deformation Mechanisms in Semi-Solid State

This study presents a new perspective on semi-solid rheology by applying the maximum dissipation rate criterion and stability analysis. Using this approach, we developed a criterion that identifies the conditions under which different deformation mechanisms dominate. A key finding is the critical role of rate-sensitivity in shaping both the mode and intensity of deformation. Specifically, we identify a threshold rate-sensitivity value of m = ۰.۲۱. Below this threshold, deformation is governed by granular processes such as grain rearrangement, jamming, and dilatancy. Above it, conversely, solid grains undergo plastic deformation instead. The analysis also establishes a strong correlation between dilatancy and rate-sensitivity. In the granular regime, higher rate dependency, resulting from increased solid fraction and stronger grain interconnections, promotes greater dilatancy and increased tendency for shear localization. At the critical threshold, localization emerges as bonds between grain agglomerates break, triggering Reynold’s dilatancy. Collectively, these findings highlight that semi-solid materials exhibit granular-like behavior, wherein grain and agglomerate rearrangement, coupled with dilatancy, drive the transition toward shear banding following the failure of inter-particle bonds. These insights provide a clearer framework for understanding and predicting the complex behavior of semi-solid materials under load.

کلیدواژه ها:

Shear localization ، dilatancy ، Dissipation ، Internal friction ، Semi-solid deformation