We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
A Micromechanical Damage Model for Quasi-Brittle Rocks Subjected to Fatigue-Creep Loading.
- Authors
Zhang, Jin; Ren, Ke; Wang, Wen; Shen, Wanqing; Ni, Tao
- 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.
- Subjects
DAMAGE models; BRITTLE materials; MECHANICAL behavior of materials; DETERIORATION of materials; MICROCRACKS; MATERIAL plasticity; ROCK deformation; FRACTURE healing
- Publication
Rock Mechanics & Rock Engineering, 2023, Vol 56, Issue 6, p4169
- ISSN
0723-2632
- Publication type
Article
- DOI
10.1007/s00603-023-03282-7