Study of the regularity of wear influence on the service life of cutting elements of bulldozers’ working bodies

Abstract

Our mathematical model describes the regularities of blade wear and takes into account the influence of different operating modes of a bulldozer when dealing with diverse soils that have different degrees of abrasiveness. When calculating the probability of failure-free operation of the bulldozer cutting elements (blades), which depends on the maximum load, it was found that the probability of failure-free operation at an operating time of 600 machine-hours is 0.7...0.75 – for soil category I; 0.5...0.55 – for soil category II; 0.3...0.35 – for soil category III. Comparison of failure-free operation probabilities has made it possible to establish that with an increase in soil density, failure-free operation probability drops by 30-40%, which suggests a significant impact of soil density on reliability of the bulldozer working equipment. In addition, this mathematical model of the total probability allows us to obtain a theoretical description of changes in failure-free operation probability of the bulldozer equipment during working processes, changes in the service life of a bulldozer blade, and taking into account the properties of the blade material. The service life of a bulldozer cutting element can be estimated by its wear, structural features of the material, geometric parameters (thickness in particular), and machine operating modes. It has been established that the regularity of changes in the service life, due to bulldozer blade wear, is exponential. The higher the soil category is, the lower the wear is, and hence the service life of a bulldozer working body. The dependence of the change in the blade service life on the time of its contact with soils of three categories was obtained as well. Thus, the maximum value of a blade service life at the beginning of operation on different soil categories was determined: 450 machine-hours – on soil category I; 350 machine-hours – on soil category II; 280 machine-hours – on soil category III.