DEVELOPMENT OF A PHYSICAL MODEL AND DETERMINATION OF SIMILARITY COEFFICIENTS OF A SPATIALLY ORIENTED KNIFE OF A BULLDOZER BLADE

Abstract

This paper considers the creation of a physical model of an equipment for cutting soils with a spatially oriented knife of a bulldozer blade for experimental studies. In order to study the process of interaction between the working body and the working environment, it is necessary to conduct experimental studies, for which, as a rule, natural objects of research or their models are used. Physical modelling preserves the physical nature of the phenomena, but changes their scale. Using the similarity theory and physical modelling, the conditions of similarity of the equipment for cutting soils with a spatially oriented knife of a bulldozer blade are determined, in which the interaction of the working body and the working environment is described by a power equation taking into account their parameters. In this case, the parameters of the natural process of interaction between the working body and the working environment are written through the parameters of the physical model and similarity coefficients. As a result of dividing the corresponding terms of the force equations of the natural equipment and the model by each other, a system of two equations was obtained that links six unknown values of the similarity coefficients. The obtained values of the similarity coefficients made it possible to build a physical model of the installation for cutting soil with a spatially oriented knife of a bulldozer blade, which is similar to the natural installation for cutting soil with a spatially oriented knife of a bulldozer blade. As a physical model of the equipment, taking into account the similarity coefficients and the envisaged research tasks, the dynamometric stand for registering the force load of the author’s design of KNUBA was modified to study the process of cutting soils with a spatially oriented knife of a bulldozer blade, which allows for full-fledged experimental studies, taking into account all the existing factors of interaction between the working medium and the working body during cutting. It is proposed to use paraffin wax as a working environment and a steel model of a spatially oriented knife as a working body.