Computational method for thermoviscoelasticity with application to rock mechanics. [Ph. D. Thesis]

Technical Report · Sun Jan 01 00:00:00 EST 1984

DOI:https://doi.org/10.2172/5020299· OSTI ID:5020299

Lee, S. C.

Large-scale numerical computations associated with rock mechanics problems have required efficient and economical models for predicting temperature, stress, failure, and deformed structural configuration under various loading conditions. To meet this requirement, the complex dependence of the properties of geological materials on the time and temperature is modified to yield a reduced time scale as a function of time and temperature under the thermorheologically simple material (TSM) postulate. The thermorheologically linear concept is adopted in the finite element formulation by uncoupling thermal and mechanical responses. The thermal responses, based on transient heat conduction or convective-diffusion, are formulated by using the two-point recurrence scheme and the upwinding scheme, respectively. An incremental solution procedure with the implicit time stepping scheme is proposed for the solution of the thermoviscoelastic response. The proposed thermoviscoelastic solution algorithm is based on the uniaxial creep experimental data and the corresponding temperature shift functions, and is intended to minimize computational efforts by allowing large time step size with stable solutions. A thermoelastic fracture formulation is also presented by introducing the degenerate quadratic isoparametric singular element for the thermally-induced line crack problems. The stress intensity factors are computed by use of the displacement method. Efficiency of the presented formulation and solution algorithm is initially demonstrated by comparison with other available solutions for a variety of problems. Subsequent field applications are made to simulate the post-burn and post-repose phases of an underground coal conversion (UCC) experiment and in-situ nuclear waste disposal management problems. 137 references, 48 figures, 6 tables.

• Research Organization: The Ohio State Univ., Columbus, OH (United States)
• DOE Contract Number: AS20-82LC10886
• OSTI ID: 5020299
• Report Number(s): DOE/LC/10886-1556; ON: DE84003087
• Resource Relation: Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ROCK MECHANICS
CALCULATION METHODS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
ROCKS
MECHANICAL PROPERTIES
ALGORITHMS
CAVITIES
CRACKS
CREEP
DEFORMATION
FAILURES
FINITE ELEMENT METHOD
HEAT TRANSFER
IN-SITU GASIFICATION
MATHEMATICAL MODELS
STRESSES
ENERGY TRANSFER
GASIFICATION
IN-SITU PROCESSING
MATHEMATICAL LOGIC
MECHANICS
NUMERICAL SOLUTION
PROCESSING
THERMOCHEMICAL PROCESSES
580300* - Mineralogy
Petrology
& Rock Mechanics- (-1989)