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| Particular research interests - Investigation of damage evolution in rocks under various loading conditions. - Fracture-induced physical processes in rocks. - Kaiser effect. - Stress measurement techniques. - Numerical simulation of rock fracturing.
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| Short description Deformation of rocks is accompanied by the formation and development of damage. This is represented by e.g. dislocations, voids, micro- and macrocracks. A deep understanding of the damage evolution is a necessary prerequisite for controlling rock behavior and more efficient technological rock fracture processes. Fracture-induced physical processes like acoustic emission and irreversible deformation are powerful tools for indirect investigation of damage formation in rocks and materials. They provide information on the damage evolution continuously during the tests, which is usually impossible when using direct microscopic observations. Natural or technological loading of rocks in situ may proceed in monotonic or cyclic mode. When cyclic loads are applied, the Kaiser effect takes place. Acoustic emission activity is low as long as the applied stress stays below the peak stress level previously experienced by the rock. As soon as this ‘memorized’ stress level is exceeded, acoustic emission activity increases dramatically. This effect is often considered as a possible basis for stress measurements in rocks and materials. Investigation of the mechanism and of fundamental features of this phenomenon under different loading regimes are the necessary prerequisites for stress measurement applications. Numerical simulation of fracturing processes delivers important information on the mechanisms of damage accumulation under different loading regimes. Failure forms obtained during numerical modeling allow a verification of the efficiency of the simulation methods. Types of cracks and the dependency of their number on stress are output data of the simulations.
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