Non-periodic inspection by Bayesian method I

Abstract

This paper introduces a Bayesian analysis methodology to determine appropriate non-periodic inspection intervals of fatigue-sensitive structures, so that their reliability remains above a prespecified minimum level throughout their service life. Fatigue damage is considered to initiate in a structural element when cracks develop, whether or not they are detected. The fatigue process then continues by crack propagation, resulting in strength degradation. If a fatigue crack is detected during an inspection, the cracked component is assumed to be repaired or replaced with a new one, resulting in the renewal of its residual strength and fatigue characteristics and increasing thus the overall reliability of the structure. The Bayesian approach introduced in this paper is unique and novel in that it allows one to utilize judiciously the results of earlier inspections for the purpose of determining the time of the next inspection and estimating the values of several parameters involved in the problem that can be treated as uncertain. Numerical simulations verify the above-mentioned capabilities of the Bayesian method.