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A Micromechanical Damage Model for Quasi-Brittle Rocks Subjected to Fatigue-Creep Loading
Abstract To accurately describe the long-term deformation of quasi-brittle rocks, a micromechanical elastoplastic model is proposed for modeling the mechanical responses under cyclic-creep loading. Based on experimental observation, the formation and propagation of microcracks are quantitatively estimated by introducing a micromechanic-based damage variable, which is related to the number of loading cycles and hold time. Thus, the macroscopic property deterioration of material is resulted from the progressive microstructural degradation, which is described by a convolutional law. Different from previous models, the evolution of damage is driven by the deviation from a self-equilibrium state. Within the elastoplastic framework, the fatigue-creep damage evolution is coupled with the plastic deformation, leading to a unified model for both instantaneous and fatigue-creep behaviors of brittle rocks. With the use of a modified returning mapping procedure, the established model is validated by comparing to the experimental results of salt rocks under both constant upper limit cyclic-creep loads and multilevel conditions. Main features of cumulative deformation, fracture mechanism and damage evolution are well captured by the proposed model.
Highlights A novel micromechanical model is developed to describe the mechanical behavior of quasi-brittle materials subjected to cyclic-creep loading.The fatigue-creep damage is physically related to the progressive microstructural degradation, due to the initiation and propagation of microcracks.A convolutional formulation is applied to describe the damage evolution considering the loading cycles and time.Numerical simulations are performed and compared to experimental data under both constant upper limit cyclic-creep loads and multilevel conditions.The acceleration of fatigue cumulative deformation and damage due to additional creep effects are confirmed.
A Micromechanical Damage Model for Quasi-Brittle Rocks Subjected to Fatigue-Creep Loading
Abstract To accurately describe the long-term deformation of quasi-brittle rocks, a micromechanical elastoplastic model is proposed for modeling the mechanical responses under cyclic-creep loading. Based on experimental observation, the formation and propagation of microcracks are quantitatively estimated by introducing a micromechanic-based damage variable, which is related to the number of loading cycles and hold time. Thus, the macroscopic property deterioration of material is resulted from the progressive microstructural degradation, which is described by a convolutional law. Different from previous models, the evolution of damage is driven by the deviation from a self-equilibrium state. Within the elastoplastic framework, the fatigue-creep damage evolution is coupled with the plastic deformation, leading to a unified model for both instantaneous and fatigue-creep behaviors of brittle rocks. With the use of a modified returning mapping procedure, the established model is validated by comparing to the experimental results of salt rocks under both constant upper limit cyclic-creep loads and multilevel conditions. Main features of cumulative deformation, fracture mechanism and damage evolution are well captured by the proposed model.
Highlights A novel micromechanical model is developed to describe the mechanical behavior of quasi-brittle materials subjected to cyclic-creep loading.The fatigue-creep damage is physically related to the progressive microstructural degradation, due to the initiation and propagation of microcracks.A convolutional formulation is applied to describe the damage evolution considering the loading cycles and time.Numerical simulations are performed and compared to experimental data under both constant upper limit cyclic-creep loads and multilevel conditions.The acceleration of fatigue cumulative deformation and damage due to additional creep effects are confirmed.
A Micromechanical Damage Model for Quasi-Brittle Rocks Subjected to Fatigue-Creep Loading
Zhang, Jin (author) / Ren, Ke (author) / Wang, Wen (author) / Shen, Wanqing (author) / Ni, Tao (author)
2023
Article (Journal)
Electronic Resource
English
BKL:
38.58
Geomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
38.58$jGeomechanik
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB41
Quasi-micromechanical damage model for brittle solids with interacting microcracks
British Library Online Contents | 2004
|Micromechanical Study of Damage and Permeability Variation in Brittle Rocks
British Library Conference Proceedings | 2006
|A micromechanics-based creep damage model for brittle rocks
Taylor & Francis Verlag | 2015
|