Теоретичний підхід до оцінки ймовірностей безвідмовної роботи транспортних та виробничих систем і ланцюгів постачань на основі їх логічних структурних схем надійності

Abstract

The purpose of the work is to develop a method of estimating the probability of failure-free operation of transport systems on the basis of their logical structural diagrams of reliability, which makes it possible to evaluate their dependence on the level of probability and the number of elements and to predict and prevent failure of a chain or system as a whole. The theoretical substantiation of reliability estimation of functioning of transport systems using logical structural schemes of reliability is given and it is revealed that their construction is based on the analysis of consequences of failures of individual elements. Properties of elements and systems for their working and inoperable states are highlighted. The formulas for calculating the probability of failure-free operation and failure of the chain or the transport system as a whole, as well as their time to failure. The dependence of the probability of failure-free operation of the transport system on the level of probability and the number of its elements is shown. Cases of serial and parallel connection of elements in the transport system chain are considered. Methods of calculation of structural reliability schemes are presented and formulas are used for estimating the probability of trouble-free operation of technical and transport systems, as well as the probability of their failures. Dependencies of reliability indicators on number of elements are constructed. It shows the reliability estimation of bridged structural diagrams using the methods of minimum paths, minimum cross sections, transformation of the connection of elements "triangle" - "asterisk", a key element. It is found that complex technical and transport systems have a large number of elements, and therefore the reliability of such systems depends not only on the reliability of the individual elements, but also on the nature of the connections between them. Carrying out the reliability analysis of transport systems is possible with the help of their structural functional circuits of reliability and unlike physical circuits that reproduce physical connections between elements, logical reliability circuits are built to show what combinations of failures of individual elements of the system lead to failure of a circuit or system in general. Thus, the construction of logical reliability schemes is based on the analysis of the consequences of the causes of failures of individual elements, which can later be used in the development of theoretical bases for improving the reliability of the functioning of road transport systems.