SELECTED PROBLEMS OF STOCHASTIC PROCESSES MODELLING OF ABRASIVE WEAR AND DURABILITYOF GRINDING WHEEL Wojciech Kacalak, Mariusz Kasprzyk, Tomasz Krzyżyński ∗ 1. PROBABLISTIC FEATURES OF GRAINS LOADING The abrasive and strength wear of a tool has a fundamental influence on a result of machining in a process of grinding. An analysis of wear of grinding grains and wheels has an essential effect on a control of grinding process and prognostics of process modifications, and on a research on new solutions in grinding tools technology 1, 2 . A course of grinding wheel wear, as a complicated process, mainly depends on the abrasive and strength wear of abrasive grains. On the other hand, a course of grinding process depends on a varying state of a grinding wheel surface, especially in an initial state after its dressing 2, 3, 4 . In a case of rough dressing, the state variation is more intensive. Every crushing an active grain results in decreasing a total grinding surface of active grains. A number of grains crumbling away in a time unit is varying, especially in conditions of self-sharpening of grains. During a limited self-sharpening, a mean time of waiting for grain crushing may depend on its loading history. The analysis presented in the paper is carried out assuming that a grain age distribution is time-varying and that a thermal and mechanical grain loading together with a grain strength are random processes. Such assumptions make it possible to treat the grinding process as a steady-state stochastic process in a time period related to one operation, and to present the grain loading as a sum of two components: mean load value p 0 =E[P s (t)] and a stochastic component x(t) of an expected value equal to zero: P(t)=E[P s (t)]+x(t). (1) ∗ Department of Fine Mechanics, Faculty of Mechanical Engineering, Koszalin University of Technology, Racławicka St. 15-17, 75-620 Koszalin, Poland