Improvement of working bodies of machines and tools for soil cultivation based on a rheological model of the soil state

One of the reasons for the high energy costs of tillage is the use of traditional methods for constructing the working surfaces of tillage working bodies. Due to the fact that there are no quantitative relationships between the parameters of the working surfaces and the values of the indicators of technological operations, the main properties of the processed layer, as well as the properties of structural materials, are taken into account in the calculations. At the same time, intrasoil rheological processes are insufficiently counted, which allow assessing the energy costs required for the deformation and destruction of the processed soil layer. The theoretical studies were based on a rheological model of the soil state, the system of equations of which allows to describe the mechanism for creating the shape of the working surface, as well as to select the parameters and operating modes of the working bodies. It was found that the destruction of the soil layer occurs on the basis of the patterns established by Mohr's strength theory, which takes into account the difference in the properties of the material under tension and compression. Full-scale experimental studies were conducted to comparatively assess the quality of the performance of technological processes by working bodies with a serial and improved shape of the working surface, as well as energy costs for soil cultivation. The results were assessed using statistical methods, taking into account the random nature of the information obtained in the probabilistic-statistical sense. The presented methodology for improving the shape of the working surface using a rheological model allows intensifying the processes of soil layer destruction by tillage working bodies performing technological operations of soil crumbling and loosening. When using loosening shovels with an improved shape of the working surface, the mathematical expectations of soil hardness in the processed layers have lower values compared to the soil condition after passing shovels with a standard shape of the working surface. It is evident that in the 5 cm soil horizon the decrease was 30 %, and at a depth of 35 cm – 8 %. This means that the soil has a looser structure due to the increased intensity of crumbling of the processed layer. subsoiler and undercutting share of the potato harvester.