The plastic deformation of solids has been historically understood as a smooth and deterministic process. However, experiments on plastic activity at small scales report a widely different picture, where plastic activity at the microscopic scale is perceived as a stochastic and highly fluctuating phenomenon occurring in the form of intermittent strain bursts, known as avalanches. Moreover, similar behavior has been reported for a wide diversity of materials and microstructures such as, e.g., crystals, glasses, rocks, wood, porous materials or even yield stress fluids which can deform elastically under an applied load. This universality suggests understanding plastic activity within a unified conceptual framework independent of microstructural details. To this end, we present a stochastic mesoscale elastoplastic model which establishes links between the understanding of plastic deformation at the microscale, based on the concept of the potential energy landscape, and the understanding at the macroscale, based on the yield function of continuum plasticity theories. The model coarse-grains microscopic details into representative mesoscopic elements equal to or larger than the characteristic length scale of the elementary flow events characteristic of a particular microstructure. The behavior of the elements is defined according to a simple set of local rules, aimed at retaining only the fundamental characteristics of the elementary events relevant to the description of plastic deformation at the mesoscopic scale. Stochastic behavior is introduced into the model by considering a statistically distributed local resistance to plastic deformation, aimed at representing at the mesoscopic scale the effects of the underlying disordered microstructure. We study the avalanche statistics, strain localization and related phenomenology on the approach to and near plastic yielding. Using a tensorial description of the elastic fields, we simulate finite-size samples under complex loading conditions such as bending or ...
Stochastic modeling of plastic flow and failure in disordered materials ; Stochastische Modellierung der plastischen Verformung und Versagens ungeordneter Materialien
2019-01-01
Theses
Electronic Resource
English
Rahmen einer elektrischen Heizvorrichtung mit einem Mittel zur plastischen Verformung
European Patent Office | 2018
|British Library Conference Proceedings | 1993
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