Application of structural methods to assess the reliability of ship’s mechanical systems

Abstract

At present, reliability indicators are of great importance at the design stages, during operation and in cases of extending the technical life. This is one of the reasons for choosing the research topic on the application of structural methods for evaluating the reliability of ship mechanical systems. The operational stage of the life cycle of ship’s mechanical systems is considered in the paper. Durability criteria such as service life, operating time, frequency of repairs are chosen as reliability indicators. In turn, work on the repair, maintenance or replacement of ship’s mechanical systems elements is carried out in accordance with the assigned regulations or in the case of an unforeseen failure. The comparison of event models of changes in the operating conditions of ship’s mechanical systems is carried out. To estimate the remaining resource in the form of graphs, events are shown by service life and operating hours, distributed by years. In order to improve the existing methods for assessing reliability, a set of elements of the average values of the residual resource and residual output is considered. The approach proposed by the authors for assessing both element by element and the entire ship mechanical system as a whole allows us to consider the residual resource from the moment of monitoring its technical condition to the transition to the limit state, to plan technical measures and prevent possible malfunctions. Three different time slices models corresponding to planned repairs and maintenance of systems, replacement of system elements and unforeseen accidents are considered in the study. The difference in the amplitudes of the calculated indicators of the ship’s mechanical systems reliability has shown that the closer the options between the maximum and minimum values are to the average, the more accurately the statistical indicators characterize this pattern. However, amplitude deviations can be used to apply fault risk assessment. This line of research seems to be important for ships in the Arctic navigation area, which are characterized by increased requirements for ship survivability.