Dynamic model of contact of grain with the surface of wood

Grinding holds the specific place among other types of machining of wood caused by specific features of the occurring physical phenomena and features of the tool. When processing the mechanical, chemical, thermal, electric and accompanying those phenomena arise a multiple-point cutting tool of preparations from wood or wood materials, naturally. The mechanical phenomena are shown owing to repeated contact of an abrasive paper from the preparation processed by a surface, that is, the fissile sliding friction. These phenomena are followed by a pollution of a cutting tool, including consolidation of space between abrasive grains that reduces operability of an abrasive paper. On the basis of the conducted theoretical researches and the analysis of the removed equations for determination of critical sizes of front corner, thickness of cut and speed of cutting, it is possible to draw conclusion that all listed parameters have significant effect on the size of bearing of the processed material abrasive grain, therefore, and on intensity of emergence of contact collapses. Increase in critical thickness of a cut leads to increase in deformation of near-surface layers of the processed material, and, therefore, and to increase in depth and the number of contact destructions. (paper)