THE ROLE OF SPALLING FRACTURE IN SCALE EFFECT IN COMPRESSIVE ICE FAILURE

摘要

Scale effects associated with compressive ice failure are related in this research to probabilistic aspects of spalling fracture, as well as effects of random averaging during non-simultaneous ice failure. In this paper the pressure-thickness scale effect and the role of spalling fractures in the birth, evolution and death of individual high pressure zones are discussed. Probabilistic aspects of the fracture process and links between the specimen size, stress distribution and flaw distribution are explored. Weakest-link type mechanisms associated with cracks emanating from zones of high shear have been identified as a key source of the scale effect. Pressure-area and pressure-thickness effects are considered in light of a new model based on probabilistic fracture mechanics. Observations of scale effects in full-scale data are discussed in a separate paper.