Abstract
Fuzzy dynamic reliability models of mechanical parallel systems with respect to stress parameters and strength parameters are developed in this paper. Strength degradation path dependence (SDPD) and failure dependence of components in the system are two main problems to be addressed in developing fuzzy dynamic reliability of mechanical systems, which are taken into account in the proposed reliability models. In addition, the SDPD sensitivity function and the failure dependence sensitivity function are defined to analyze the influences of the fuzzy characteristics of stress on the effects of SDPD and failure dependence of mechanical components on dynamic reliability. The bolted joint systems for connection between launch vehicle and satellite are chosen as illustrative examples to demonstrate the proposed model. Moreover, Monte Carlo simulations are carried out to validate the effectiveness of the proposed models. The results show that SDPD and failure dependence of components have significant impacts on fuzzy dynamic reliability of mechanical systems. Besides, the influences of the fuzzy characteristics of stress on SDPD sensitivity and that on failure dependence sensitivity are different.
Highlights
Over the last few decades, reliability models of mechanical systems have been well reported in the probability context [1,2,3,4,5]
In the proposed reliability models, the Strength degradation path dependence (SDPD) and failure dependence of components in a mechanical parallel system are taken into account
Strength distribution of components at each load application is always adopted in conventional dynamic reliability models, which is determined by the assumed stochastic process
Summary
Over the last few decades, reliability models of mechanical systems have been well reported in the probability context [1,2,3,4,5]. Due to the complexity of the operational environment, it is difficult to obtain a large number of samples to precisely describe the statistical characteristics of stress caused by environmental load on the mechanical systems in aerospace products, especially in the preliminary design stage where many factors have to be determined by the judgment of engineers In this case, it can only increase the uncertainty in reliability estimation to adopt the imprecise pdf of stress. Fuzzy dynamic reliability models of parallel mechanical systems with respect to stress and material parameters, which consider failure dependence between different components in a system, are seldom reported. The sensitivity analysis of dynamic system reliability with respect to fuzzy parameters of stress will be performed in order to present how the fuzzy characteristics of stress affect the failure dependence behavior of components in mechanical systems. The influences of fuzzy characteristics of stress on both the effects of SDPD and the effects of failure dependence on reliability are analyzed via the numerical examples
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
