Prognosis under uncertainty – An idealised computational case study

Issue title: The International Conference on Engineering Dynamics 2007

Article type: Research Article

Authors: Worden, Keith | Manson, Graeme

Affiliations: Dynamics Research Group, Department of Mechanical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK

Note: [] Corresponding author. E-mail: k.worden@sheffield.ac.uk

Abstract: The object of this paper is to investigate computationally the possibility of damage prognosis in a structure under the most idealised circumstances. A simple isotropic material – Titanium alloy Ti-6Al-4V – is assumed. The structure is a simple finite plate under harmonic uniaxial loading and the damage is assumed to be a central mode 1 through crack for which various approximations to the stress intensity factor are known. The damage propagation model is the Paris-Erdogan law. Where the paper departs from complete simplicity is in the assumption that the parameters of the damage propagation law are uncertain. The paper investigates the effect of the parameter uncertainty on the estimated lifetime of the specimen. Two approaches are adopted for the uncertainty propagation, a statistical Monte Carlo scheme and one based on interval arithmetic.

Keywords: Damage prognosis, uncertainty propagation, Monte Carlo analysis, interval analysis

Journal: Shock and Vibration, vol. 15, no. 3-4, pp. 231-243, 2008