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https://hdl.handle.net/11681/9285| Title: | Thermodynamic model of creep at constant stresses and constant strain rates |
| Authors: | Research Institute of Foundations and Underground Structures (Moscow, Russia) Fish, Anatoly M. |
| Keywords: | Activation energy Failure criteria Stress-strain Thermodynamics Strains and stresses Constitutive equation Frozen soils Frozen ground Creep model Ice Ductile materials Soils Entropy Strength |
| Publisher: | Cold Regions Research and Engineering Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
| Series/Report no.: | CRREL report ; 83-33. |
| Description: | CRREL Report Abstract: A thermodynamic model has been developed that for the first time describes the entire creep process, including primary, secondary, and tertiary creep, and failure for both constant stress (CS) tests (σ = const.) and constant strain rate (CSR) tests (ϵ = const.), in the form of a unified constitutive equation and unified failure criteria. Deformation and failure are considered as a single thermoactivated process in which the dominant role belongs to the change of entropy. Failure occurs when the entropy change is zero. At that moment the strain rates in CS tests reach the minima and stress in CSR tests reaches the maximum (peak) values. Families of creep (ϵ vs τ) and stress-strain (σ vs ϵ) curves, obtained from uniaxial compression CS and CSR tests of frozen soil, respectively (both presented in dimensionless coordinates), are plotted as straight lines and are superposed, confirming the unity of the deformation and failure process and the validity of the model. A method is developed for determining the parameters of the model, so that creep deformation and the stress-strain relationship of ductile materials such as soils can be predicted based upon information obtained from either type of test. |
| Rights: | Approved for public release; distribution is unlimited. |
| URI: | http://hdl.handle.net/11681/9285 |
| Appears in Collections: | CRREL Report |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| CR-83-33.pdf | 1.42 MB | Adobe PDF |  View/Open |