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Title: Modelling NDE pulse-echo inspection of misorientated planar rough defects using an elastic finite element method

Pulse-echo ultrasonic NDE examination of large pressure vessel forgings is a design and construction code requirement in the power generation industry. Such inspections aim to size and characterise potential defects that may have formed during the forging process. Typically these defects have a range of orientations and surface roughnesses which can greatly affect ultrasonic wave scattering behaviour. Ultrasonic modelling techniques can provide insight into defect response and therefore aid in characterisation. However, analytical approaches to solving these scattering problems can become inaccurate, especially when applied to increasingly complex defect geometries. To overcome these limitations a elastic Finite Element (FE) method has been developed to simulate pulse-echo inspections of embedded planar defects. The FE model comprises a significantly reduced spatial domain allowing for a Monte-Carlo based approach to consider multiple realisations of defect orientation and surface roughness. The results confirm that defects aligned perpendicular to the path of beam propagation attenuate ultrasonic signals according to the level of surface roughness. However, for defects orientated away from this plane, surface roughness can increase the magnitude of the scattered component propagating back along the path of the incident beam. This study therefore highlights instances where defect roughness increases the magnitude of ultrasonic scatteredmore » signals, as opposed to attenuation which is more often assumed.« less
Authors:
;  [1] ;  [2]
  1. UK Research Centre for NDE, Imperial College London, Exhibition Road, London, SW7 2AZ (United Kingdom)
  2. Rolls-Royce Nuclear, PO BOX 2000, Derby, DE21 7XX (United Kingdom)
Publication Date:
OSTI Identifier:
22391230
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1650; Journal Issue: 1; Conference: 41. Annual Review of Progress in Quantitative Nondestructive Evaluation, Boise, ID (United States), 20-25 Jul 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPUTERIZED SIMULATION; DEFECTS; FINITE ELEMENT METHOD; INSPECTION; MATHEMATICAL MODELS; MONTE CARLO METHOD; POWER GENERATION; PRESSURE VESSELS; ROUGHNESS; SCATTERING; SIGNALS; SURFACES; ULTRASONIC WAVES; WAVE PROPAGATION