A COMPLEX APPROACH IN ASSESSING RELIABILITY INDICATORS OF ELEMENTS OF TECHNICAL SYSTEMS WHEN DEGRADATION FAILURES OCCUR

The construction and practical use of complexes of mechanical reliability models creates real prerequisites for the transition to resource design of assembly units and aggregates of  mobile machines. Therefore, the article solves the tasks of building complexes of inverted stochastic models, which provide the possibility of joint statistical analysis of heterogeneous information about reliability in cases of types of destruction typical for machine elements: during wear and fatigue. A fairly complete and convenient method for solving many problems of mechanical reliability is given for describing a non-stationary monotonic degradation process, which consists in the task of the type of its function or the density of distribution in time segments with parameters that are deterministic monotonic functions of time or working time in load cycles. Such functions should be perceived as parametric. Schemes of models of two main types of degradation processes in machine elements are also given: monotonically increasing, associated with wear and monotonically decreasing, due to fatigue failure. At the same time, the process corresponding to wear is formed by random realizations of a change in the failure parameter over time, and the process characterizing fatigue failure is formed by a set of random individual fatigue curves that depend on cyclic durability. The considered theoretical analysis of the main degradation processes that determine the mechanical reliability of machine elements made it possible to develop a universal approach to building complexes of stochastic reliability models, which provides the possibility of joint statistical evaluation of model parameters for processes caused by wear and tear and fatigue destruction. The practical use of the proposed complexes of mechanical reliability models is expedient both for accelerated assessment and for  predicting reliability at the stage of resource design of elements of mobile machines.