Uncertainties in Modeling the Lifetime-and-Functional Properties of Gear Trains and Transmissions and Ways to Reduce Them

Abstract

Typical cases of problem situations associated with uncertainties in modeling properties of gears and transmissions of cars, tractors and other similar technically complicated items are considered. Such items work in a changing environment, consist of many heterogeneous non-standard components and are controlled by the operator. Typical uncertainties include: isomorphism, incorrect schematization, lack of detailed data about the item, variation of the environment, the presence of a variety of calculation (modeling) methods, etc. Ways of resolving problem situations associated with uncertainties are developed. Reducing the uncertainty in modeling the individual lifetime of an item can be achieved through digitalization (diagnostic data, recognition of item state). When uncertainty is unavoidable, it is recommended to create a decision-making space that is convenient for stakeholders to analyze and assess the degree of risk resulting from their decisions. It is shown that situations in decision-making can be significantly enhance by introducing an indicator that successfully describes a set of basic properties of an item. The main provisions of the article are accompanied with examples from the authors’ own practice. The considered approaches are methodologically typical for many complex mechanical and combined items based on mechanical systems.