Modeling of the failure formation mechanism in non-recoverable and recoverable systems

In this article, the object of research is complex functional aircraft systems. The subject of the study includes a methodological approach to systems reliability calculation. The theme of this work is development of the methods for the complex systems reliability assessing. The aim of this work is to study the validity and adequacy of the methodologi- cal approach to the traditional reliability theory in the calculations of recoverable redundant systems. Traditional methods include the methods that are based on the use of the multiplication theorem of probabilities. In the production section of faultlessness calculating solving problem are the conditions for the system failure of. These conditions are ignored, using traditional methods of solving problems. It is shown that according to the traditional solution, systems are only refused if all elements fail. When calculating the majority system, probability of its failure is determined by summing the failure probability for two states. And it is assumed that the second refusal is realized in the previously failed system. Failures of elements that determine the loss of system performance are realized at discrete instants of time, but, with the traditional solution, discreteness is not taken into account. The methodological approach proposed by the authors is based on the notion that, in a stationary process, the failure probability of an element in the operable part of the system is determined by the total density probability of the failure streams of the elements making up this part of the system and their previous generation. Using the methods proposed by the authors for solving the problems of reliability calculating of these systems, the theorem of multiplying probabilities is not used. Time intervals are determined on which the elements of the system fail, and reduce its efficiency. Taking into account changes in the system structure, solutions are proposed as the failure in it develops. The results obtained according to the proposed approach strictly correspond to the failure conditions of the systems. The validity of the approach is confirmed by the results of experimental studies. The methods proposed in the work can be used in calculating the reliability of functional systems of aircraft and spacecraft.