Efficiency upgrading techniques for assembly products of space-rocket equipment

Аuthors

Zolotov A. A.^*, Nurullaev E. D.

Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

*e-mail: alexandrzolotov41@mail.ru

Abstract

The article considers design techniques for reliability and safety upgrade of space-rocket systems (SRS) operation.

The authors have suggested the reliability demonstration technique of the systems when measuring operational integrity parameters, as well as solved the problem of SRS reliability demonstration control under amount of testing limitations. Information content of tests has been enhanced. The paper defines the areas of effective and bearable values of the parameters under study. Failure probability was evaluated for each parameter through coefficients of variation of effective and bearable parameters values and safety margin. Interval estimation was calculated to provide guaranteed result. Average margin value was evaluated using operational integrity values sampling. For the accepted level of confidence, lower and upper boundaries of reliability were calculated. The sampling can be arranged using testing results carried out in the course of experimental development. Thus, amounts of redundancy introduction provides SRS reliability requirements for the limited amount of testing. It is very important in relation to time limit.

We suggested systems reliability demonstration technique during extra heavy testing, and solved the problem of SRS operational integrity control during contingency rating. Availability of redundancy of system parameters characterizing its operational integrity is suggested. Loading factor was determined on account of product operation in both effective and bearable modes. After extra heavy testing the lower boundary of reliability for the accepted level of confidence was determined using tables. Thus, the introduction of amounts of redundancy provides the SRS heavy testing reliability requirements. It is of prime importance concerning one-shot products.

The paper suggests an SRS failure occurrence evaluation technique, and solves the problem of a bad product acceptance probability.

The technique of SRS validity control parameters optimization is offered. The problem of optimum tests number determining with allowance for tests expenses and inspection error damage is solved.

The algorithms using the offered techniques, which are illustrated with modeled examples, are presented.

The received results can be useful for the design offices workers, research institutes, scientific and production enterprises during developing, as well as operation and maintenance of highly reliable SRS.

Keywords:

reliability, number of tests, risk of failures

References

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