Journal of Mechanical Engineering (Jun 2019)
Calculation of Indicators of Reliability of Technical Systems by the Typical Structural Scheme Method
Abstract
A method for calculating the indicators of structural reliability of systems with a large number of elements is presented. The method is based on the use of typical structural schemes, reflecting the concept of connections between elements. It is shown how, by sup-plementing and combining typical structures, one can create graphological structures to perform calculations of reliability indicators. The approach can be used in the development of algorithms and software solutions on computer problems, based on assessments of the structural reliability of systems. Such tasks, in particular, include: assessing the safety of nuclear units, planning their repairs, assessing the reliability of directional systems for transporting media, and estimating the residual resources of technical facilities. Various private methods have been developed for their solution. However, it is not possible to stan-dardize calculations of reliability indicators because of the diversity of systems and condi-tions of their operation. The presented approach is focused on the automation of calcula-tions of indicators of structural reliability of a wide class of technical systems. It is based on the proof of the existence of a calculation algorithm on a set of typical structural schemes. It is assumed that the computer recognizes images of typical structures as part of graphological images of systems. The content of the problem is as follows. A technical sys-tem is given. It is required to build a graphological image and calculate the index of its structural reliability. The proposed calculation method is based on the representation of the graphological image of the system in the form of a composition of graphological images of typical structures, the reliability indices of which are calculable. They are substituted by individual elements with calculated values of the reliability index. Such substitutions make it possible to simplify the initial graphological image of the system by reducing the total number of elements and calculate the system reliability indicator. The calculation and sub-stitution procedure continues until the graphical image of the system has one typical struc-ture for which we calculate the reliability index. The number of elements in the system is unlimited, since the subsitution procedure is carried out sequentially until the formation of one typical structure. A significant limitation in the application of the method to the calcu-lation of the structural reliability of a wide range of complex technical systems is due to the limitations of many typical structures. However, such a bank of typical structures can be created and used in the development of appropriate design programs.
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