STATISTICAL STUDY OF STRESS-INDUCED MICROSTRUCTURES IN SELECTED ROCK AND CONCRETE

PROPERTIES OF ELASTIC-BRITTLE MATERIALS CHANGE UNDER STRESSES WHICH ARE HIGH ENOUGH TO INDUCE MICROSTRUCTURAL ALTERNATIONS. THESE MICROSTRUCTURAL CHANGES ULTIMATELY ARE THE CAUSES FOR MACROSCALE FAILURE OF MATERIALS. OBSERVATIONS AND STATISTICAL STUDIES OF THE STRESS-INDUCED MICROSTRUCTURAL CHANGES (DAMAGE TO THE MATERIAL) IN RELATION TO THE STRESS CONDITIONS, AND THEORETICAL ANALYSIS OF EFFECTIVE MECHANICAL PROPERTIES AS FUNCTIONS OF THE DAMAGE, WILL PROVIDE A BASIS FOR EVENTUAL INCORPORATION IN CONSTITUTIVE MODELS. A DETAILED EVALUATION OF STRESS-INDUCED MICROSTRUCTURES IN ROCK AND CONCRETE TO REVEAL THE STATISTICAL RELATIONSHIP BETWEEN THE MICROSTRUCTURES AND APPLIED STRESSES IS PROPOSED. THE STATISTICAL RESULT OF THE STUDY WILL SERVE AS A DATA BASE FOR THE LINKAGE BETWEEN THE MACROSCALE AND MICROSCALE BEHAVIOR OF ELASTIC-BRITTLE MATERIALS. USING ENERGY CONVERSATION PRINCIPLES, THE MACROSCOPIC BEHAVIOR OF A DAMAGE MATERIAL CAN BE REPRESENTED BY A SERIES OF "EFFECTIVE" MECHANICAL PROPERTIES, AS FUNCTIONS OF STRESS CONDITIONS, TO WHICH THE MATERIAL IS SUBJECTED. THE EXPLICIT SOLUTIONS OF EFFECTIVE MECHANICAL PROPERTIES WILL BE THE END PRODUCT OF THE THEORETICAL PORTION OF THIS PROPOSED STUDY.