Agricultural Equipment Design Optimization Based on the Inversion Method

Abstract

A representative statistical analysis of the operational information of the reliability of tillage units, which have operating devices with an oscillating motion, was carried out. The results of the working condition of thirteen cultivators in operation, with an accumulated operating time of more than 280 thousand hectares, were considered. A field investigation was carried out in seven regions in Ukraine, characterizing various edaphoclimatic conditions. The occurrence of sudden failures due to the fracture of the elastic struttings of cultivator operating devices was established. There were 42 sudden failures among 260 tested struttings. The inversion method was proposed to determine the elastic elements’ loading parameters being a combination of the theoretical reliability model, which was adapted to the probability of failure-free operation prediction due to the fact of sudden failures, and statistical model-specific indicators that were obtained depending on the operating elastic struttings. The given approach, based on the evaluation of the operating tillage units, made it possible to determine the impact of the load on the existing designs of the machines and their elements leading to the sudden failures. It was possible to present such an influence in the form of a probabilistically justified reserve factor, which had an empirical basis and allowed for the design of the next generation of technical systems and their elements to correct the theoretically assumed load value. Constructive and technological changes in the design, based on the approach described in this article, provide an opportunity to manage the level of reliability for economic and image reasons.

Keywords

• inversion method
• mechanical reliability
• elastic element
• extreme load
• probability of failure-free operation
• load factor