ACOUSTIC
EMISSION & NDT SCIENTIFIC PUBLICATIONS
Advanced acoustic emission for on-stream inspection of
petrochemical vessels
To appear in the proceedings of Emerging Technologies in NDT,
Held 26-28 May 2003, Thessaloniki, Greece
M.F.Carlos, D.Wang, S.Vahaviolos, A. Anastassopoulos
The “Advanced Acoustic
Emission (AE) for on-stream inspection” project is a
PetroleumEnvironmental Research Forum (PERF) sponsored
initiative. The objective of the project is to develop
reliableAE technology for on-stream inspection of pressure
equipment in the petroleum refining and chemical indus-tries,
instead of internal inspection. To achieve this objective,
the project has focused on four key areas of devel-opment,
including:
• accurate AE source location
algorithms,
• quantitative AE-fracture
mechanics correlations for fitness for service assessment,
• reliable AE source
discrimination techniques, and
• testing guidelines,
procedures and inspector qualification.
The completed work items have
been integrated into a high-speed, parallel-processing, cost-effective
AE systemand are currently being evaluated in lab and field
AE tests. Many unique and exciting capabilities have
beenimplemented in the “pre-test” AE test planning functions,
and “post-test” automated AE data analysis process.Included
in the pre-test planning is the capability to predict the AE
response in terms of the source moment tensorusing Green’s
functions and integration of the actual sensor response with
these predictions. Velocity predictioncalculations are aided
by three-dimensional dispersion curves (includes signal
amplitude) that take into accountvessel material as well as
AE source type, orientation and depth in the material. In
addition, Fitness for Service(FFS) analysis is integrated
into the AE software to provide API 579 Level II analysis to
help prioritize AE indi-cations for follow-up inspection.
Analysis and results of the various software functions, will
be presented toshow the unique “marriage” of past
theoretical models to AE and Fracture mechanics FFS
assessment.