Reliability evaluation and optimisation of imperfect inspections for a component with multi-defects

• Published in: Reliability engineering & system safety Vol. 92; no. 1; pp. 65 - 73
• Main Authors: Zhao, Jianmin, Chan, A.H.C., Roberts, C., Madelin, K.B.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2007; Elsevier
• Subjects: Applied sciences; Defect; Exact sciences and technology; Failure; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Imperfect inspection; Industrial metrology. Testing; Mechanical engineering. Machine design; Optimisation; Physics; Reliability; Solid mechanics; Structural and continuum mechanics; Defect; Reliability; Optimisation; Imperfect inspection; Failure; Rupture; Delay time; Maintenance; Repair; Modeling; Poisson process
• ISSN: 0951-8320; 1879-0836
• DOI: 10.1016/j.ress.2005.11.003

In this paper, a model is developed to evaluate the reliability and optimise the inspection schedule for a multi-defect component. The model uses a non-homogeneous Poisson process (NHPP) method in conjunction with a delay time approach. The inspections are designed to detect any defects in the component, however it can be imperfect. The defect is a definable state before a functional failure happens to the component. Occurrences of defects are assumed to follow an NHPP and a defect will be minimally repaired if it is identified during an inspection. It is shown that the failures occurring in an interval of inspection will also follow an NHPP. The situation of imperfect inspections and non-constant inspection intervals are considered. An algorithm is presented to optimise the intervals of inspections in order to maximise the reliability of the component, and the properties of the algorithm are shown. A numerical example with parametric study is given to show the performance of the model and the algorithm.