Nonlinear Creep Constitutive Model of Fractured Granite and Its Parameters Analysis
The creep behavior of fractured granite is crucial for the long-term stability and safety of high-level radioactive waste disposal repositories. This study proposes a damaged elastic-visco-plastic model, considering the effect of stress-induced damage accumulation during the creep process. The model...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Editorial Department of Journal of Sichuan University (Engineering Science Edition)
2024-07-01
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| Series: | 工程科学与技术 |
| Subjects: | |
| Online Access: | http://jsuese.scu.edu.cn/thesisDetails#10.12454/j.jsuese.202201384 |
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| Summary: | The creep behavior of fractured granite is crucial for the long-term stability and safety of high-level radioactive waste disposal repositories. This study proposes a damaged elastic-visco-plastic model, considering the effect of stress-induced damage accumulation during the creep process. The model replaces the Newtonian element with a fractional derivative viscoelastic element and the classical viscoelastic body with a damaged elastic-visco-plastic body within the Burgers model framework. Consequently, a new nonlinear creep constitutive model and its corresponding 3D creep equation for fractured granite are established. The model parameters and their variations with stress levels are determined by fitting the experimental creep results of granite samples with fractures inclined at 30 and 45 degrees under varying stress conditions. Additionally, the suitability and rationality of the creep model are verified. A sensitivity study is conducted to examine the impacts of the fractional derivative order, damage factor, and stress level on the creep strain of fractured granite. The findings suggest that in specific cases, the nonlinear creep constitutive model can be simplified to the classical Burgers model. Importantly, the proposed model accurately describes the three stages of the creep failure process, particularly highlighting the nonlinear characteristics of creep strain in the accelerated stage. |
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| ISSN: | 2096-3246 |