PROBABILISTIC-DETERMINISTIC TRANSITION INVOLVED IN A FRAGMENTATION PROCESS OF BRITTLE MATERIALS: APPLICATION TO A HIGH PERFORMANCE CONCRETE

Abstract

DYNAMIC LOADINGS PRODUCE HIGH STRESS WAVES LEADING TO THE FRAGMENTATION OF BRITTLE MATERIALS SUCH AS CERAMICS, CONCRETE, GLASS AND ROCKS. THE MAIN MECHANISM USED TO EXPLAIN THE CHANGE OF THE NUMBER OF FRAGMENTS WITH THE STRESS RATE IS A SHIELDING PHENOMENON. HOWEVER, UNDER QUASI STATIC LOADING CONDITIONS, A WEAKEST LINK HYPOTHESIS MAY BE APPLICABLE. THEREFORE, DEPENDING ON THE LOCAL STRAIN OR STRESS RATE, DI®ERENT FRAGMENTATION REGIMES ARE OBSERVED. ONE REGIME CORRESPONDS TO SINGLE FRAGMENTATION FOR WHICH A PROBABILISTIC APPROACH IS NEEDED. CONVERSELY, THE MULTIPLE FRAGMENTATION REGIME MAY BE DESCRIBED BY A DETERMINISTIC APPROACH. THE TRANSITION BETWEEN THE TWO FRAGMENTATION REGIMES IS DISCUSSED. A DAMAGE MODEL DESCRIBING DYNAMIC FRAGMENTATION IS APPLIED TO A HIGH PERFORMANCE CONCRETE.