Reliability of systems with periodic piecewise constant failure rate

Аннотация

Determination of the need for and timeliness of repairs of machines (or for replacing their components) are primary concerns of applied reliability theory. A decision is made as to whether repairs need to be carried out or not on the basis of on examination of the efficiency of the machine, which is determined by comparison of a number of economic, technical, and ecological indices. It is clear that this is a multicriterion problem. One of the most important criteria (but not the sole one) is mean operating time to failure. In general, assuming that there is a representative failure database, this is done via procedures of reliability theory. The paper discusses the need of the solution of reliability problems for a class of objects subjected to a nonstationary failure flow at a periodic piecewise constant rate. Examples of such objects are given. The reliability function and mean operating time to failure are determined analytically. A model of failure is given using states of an object that are each determined by a specific failure rate. The object states are repeated in a given period. In addition, the special case of two states that correspond to the seasonally changing of failure rate is considered. An analysis of the effects of various failure rates on the mean operating time to failure is carried out.