INTERACTIVE SOFTWARE TOOLS FOR INSPECTION
QUALIFICATION
P. Leggat, D. McNab and A. McNab
Centre for Ultrasonic Engineering, Department of Electronic and Electrical
Engineering, University of Strathclyde, Glasgow, Gl 1XW, UK
ABSTRACT. The demonstration of ultrasonic inspection reliability through Inspection
Qualification is important for non-routine or safety critical tests. However, since
Inspection Qualification is time consuming and costly, the provision of interactive software
tools to aid the process offers substantial advantages. This paper describes such an
interactive tool set to aid Inspection Qualification. Operating within a 3D CAD
environment it consists of ray tracing, coverage map and defect/ray interaction tools.
Initial ray amplitudes are also calculated and displayed, and estimation of favorable surface
scanning positions determined.
INTRODUCTION
Inspection Qualification tends to be carried out where component integrity is
essential for safety or in cases of non-routine geometries. A key element in this
process, as developed by the European Network for Inspection Qualification (ENIQ),
is to produce a Technical Justification which documents evidence that a testing
procedure would detect established worst case defects present within the examined
component. The Technical Justification details all the information relating to the
testing procedure and combines evidence from physical reasoning and simulation
models linked to experiments on test pieces. This builds up to a sizeable document
that is time consuming and costly to produce.
This paper describes an interactive software toolset that can aid the process of
inspection design and provide a speedier means of producing evidence for Inspection
Qualification. The first of these is the ray tracing tool, which allows the user to track
the path of the ultrasound within the component. Following on from this is the
coverage map tool which establishes the volumetric coverage achieved during the
scan. Also incorporated is the defect/ray interaction tool which provides feed-back on
defect/ray incident angles achieved during the scan. In addition, predictions of ray
amplitudes are determined. And lastly, back projection of normal rays from
hypothetical defects are established. These tools will aid the NDT engineer in
designing ultrasonic tests and assist him in collecting proof that the tests are fit for
their intended purpose.
CP657, Review of Quantitative Nondestructive Evaluation Vol. 22, ed. by D. O. Thompson and D. E. Chimenti
© 2003 American Institute of Physics 0-7354-0117-9/03/S20.00
1884
(a)
(a)
(b)
FIGURE 1.
(a) Plate
Plate butt
buttweld
weldcomponent
componentwith
withstriplike
striplike
defect
inserted.
Nozzle
component
FIGURE
1. (a)
defect
inserted,
(b) (b)
Nozzle
component
with
with circular
inserted.
circular
defectdefect
inserted.
SOFTWARE PLATFORM
SOFTWARE
PLATFORM
The The
tool tool
set operates
within
a software
platform
[1] designed
using using
VisualVisual
C++ and
set operates
within
a software
platform
[1] designed
using
OpenGL
for
the
graphical
display.
The
software
contains
a
number
of
scalable
C++ and using OpenGL for the graphical display. The software contains
a
CAD
geometries
that
are
represented
by
facets.
Strip
like,
circular
and
elliptical
facets
number of scalable CAD geometries that are represented by facets. Strip like,
can be inserted
into the facets
components
to inserted
representinto
possible
defects. Figure
1 shows two
circular
and elliptical
can be
the components
to represent
geometries
with
defects
inserted.
possible defects. Figure 1 shows two geometries with defects inserted.
RAY TRACING
RAY
TRACING
The The
ray tracing
tool tool
displays
raysrays
that that
represent
the path
of the
ultrasound
within
ray tracing
displays
represent
the path
of the
ultrasound
the
component.
Both
a
selected
dB-down
contour
of
the
beam
and
the
beam
axis
within the component. Both a selected dB-down contour of the beam and the are
represented,
one principalinplane
of the beam.
tool
can be
used
to can
emulate
beam
axis arein represented,
one principal
plane This
of the
beam.
This
tool
be a
scan
of
the
component.
To
execute
a
ray
trace
there
are
two
options
within
used to emulate a scan of the component. To execute a ray trace there are two the
software for setting up the scan.
options within the software for setting up the scan.
The first option requires the user to select a component surface, a scan origin and
The first option requires the user to select a component surface, a scan
scanning increments in the primary and secondary directions; for a flat plate the
origin and scanning increments in the primary and secondary directions; for a flat
primary and secondary directions would normally correspond to the x and y axes of the
plate the primary and secondary directions would normally correspond to the x
component.
and y axes of the component.
The second option is to design an algorithm, or 'geometry code'. This approach is
The second option is to design an algorithm, or ‘geometry code’. This
used in industry to establish the exact positions of the probes on the component
approach is used in industry to establish the exact positions of the probes on the
surface, given the coordinates of the controlling manipulator. Both these options are
component surface, given the coordinates of the controlling manipulator. Both
suitable for flat scanning surfaces, but in the case of curved surfaces, geometry codes
these options are suitable for flat scanning surfaces, but in the case of curved
are employed to overcome the inaccuracies of the faceted surface representation of the
surfaces,
geometry
are employed
overcome
inaccuracies
of the
component.
Figure 2codes
illustrates
ray tracingtowithin
a pipe the
component.
The mainbeam
faceted
surface
representation
of
the
component.
Figure
2
illustrates
ray
tracing
and the upper and lower extents of the 6dB beam width are represented by colour
within
a pipe component. The mainbeam and the upper and lower extents of the
coded rays.
6dBStriplike,
beam width
are represented
bydefects
colour can
coded
circular
and elliptical
be rays.
inserted into the component and the
Striplike,
circular
and
elliptical
defects
insertedand
into
the- component
defect properties - rotation (orientation), skew,can
tilt,be
position
size
can be altered
and
the
defect
properties
rotation
(orientation),
skew,
tilt,
position
size in
- can
through the defect dialog. The defect dialog for the strip-like defect isand
shown
Figure
be
altered
through
the
defect
dialog.
The
defect
dialog
for
the
strip-like
defect
is
3. The defect orientation, tilt and skew can also be altered using defect selection dials,
shown in Figure 3. The defect orientation, tilt and skew can also be altered using
defect selection dials, shown in Figure 4, and the defect can also be moved to the
required position by dragging with the mouse.
1885
shown in Figure 4, and the defect can also be moved to the required position by
dragging with the mouse.
14)
24)
O
r
[200_____1300_____l4Tin_____L5Q1
FIGURE
FIGURE 2.
2. Ray
Raytracing
tracingwithin
withinaapipe
pipecomponent.
component.
FIGURE3.3. Defect
Defectdialog
dialogfor
forthe
thestrip-like
strip-likedefect.
defect.
FIGURE
1886
—Ill
FIGURE4.4. Defect
Defect dials.
dials.
FIGURE
COVERAGE MAPS
MAPS
COVERAGE
Without
reference
to hypothetical
any hypothetical
defect,
coverage
the
Without
reference
to any
defect,
coverage
maps maps
definedefine
the volumetric
volumetric
coverage
achieved
within
a
component
by
scanning
with
the
probe.
coverage achieved within a component by scanning with the probe. Within the
Within the Technical Justification, coverage maps are produced for each probe to
Technical
Justification, coverage maps are produced for each probe to be used to
be used to demonstrate that full coverage of the volume of interest is achievable.
demonstrate
that full coverage of the volume of interest is achievable. The coverage
The coverage mapping tool utilizes information from the ray trace of the scan. It
mapping tool utilizes information from the ray
trace of the scan. It operates by
operates by voxelising the component into 1mm3 voxels; if a voxel is ‘hit’ by the
voxelising the component into 1mm3 voxels; if a voxel is 'hit' by the beam, then that
beam, then that voxel is tagged and assigned a flag. This provides a method for
voxel
is tagged
and beam
assigned
a flag.in This
provides
a methodJustification.
for determining
determining
probe
coverage
3D for
the Technical
At probe
beam
coverage
in
3D
for
the
Technical
Justification.
At
present
this
information
present this information is in 2D and is calculated ‘by hand’. Figure 5 illustrates is in
2D
is calculated
'by hand'.
5 illustrates
the with
output
from the coverage
the and
output
from the coverage
mapFigure
tool when
a flat plate,
an excavated
section map
tool
when
a
flat
plate,
with
an
excavated
section
above
the
weld
area,
is
scanned
above the weld area, is scanned using a 70º probe. The figure shows the effect of using
areflection
70° probe.
The
shows
the effect of
reflection
the face oftothe
excavation,
from
thefigure
face of
the excavation,
together
withfrom
colour-coding
indicate
together
with
colour-coding
to
indicate
coverage
by
the
beam
axis
and
the
leading
coverage by the beam axis and the leading and trailing beam edges. In this and
trailing
edges.
small the
section
of thesection,
weld area,
below the
instancebeam
a small
sectionInofthis
the instance
weld area,a below
excavated
is missed
excavated
during thesection,
scan. is missed during the scan.
J.-1P.Q...........................1-50...
FIGURE 5. Example of coverage map display for a 70º probe scan of a flat plate.
FIGURE 5. Example of coverage map display for a 70° probe scan of a flat plate.
1887
(b)
(a)
FIGURE6.6. (a)
(a) Strip-like
Strip-like defect
defect inserted
Incident
angle
mapmap
on defect
face.face.
FIGURE
insertedinto
intothe
thewall
wallofofa pipe,
a pipe.(b)(b)
Incident
angle
on defect
RAYTRACING
TRACING TOOLS
TOOLS FOR
RAY
FORDECISION
DECISIONSUPPORT
SUPPORT
Technical
Justification
documents
may
full
Technical
Justification
documents
maypresently
presentlyinclude
includeresults
results from
from full
simulation modelling and evidence from experimental test blocks. It may not be
simulation modelling and evidence from experimental test blocks. It may not be
necessary to produce extensive evidence at this highest level if the ray tracing tools
necessary
to produce
this highestdefect
leveland
if the
ray tracing
can, through
physical extensive
reasoning, evidence
establish at
a worst-case
demonstrate
its
tools
can,
through
physical
reasoning,
establish
a
worst-case
defect
detectability. To this end, the tool presently establishes the incident angle of theand
ray
demonstrate
itsthedetectability.
To allows
this end,
the tool
presently
establishes
the
with respect to
defect normal and
prediction
of ray
amplitudes
along the ray.
incident angle of the ray with respect to the defect normal and allows prediction of
ray
amplitudes
along the ray.
Defect/Ray
Interaction
The defect/ray
interaction tool allows the user to establish the incident angles of the
Defect/Ray
Interaction
beam axis ray with respect to the defect normal during the scan. This tool utilizes
information
from the ray
trace of thetool
scanallows
and results
are displayed
as a the
colour
coded
The defect/ray
interaction
the user
to establish
incident
map on
for incident
angles
0° to 90°.
Figure
6(a)the
shows
angles
ofthe
thedefect
beam face,
axis ray
with respect
to from
the defect
normal
during
scan.a stripThis
likeutilizes
defect inserted
into afrom
pipe the
wall.rayThe
output
from
theand
defect/ray
toolas
is
tool
information
trace
of the
scan
results interaction
are displayed
in Figure
6(b).theIndefect
futureface,
therefor
willincident
be an option
to from
display
information
a illustrated
colour coded
map on
angles
0º this
to 90º.
Figure
numerically.
6(a)
shows a strip-like defect inserted into a pipe wall. The output from the
defect/ray
interaction tool is illustrated in Figure 6(b). In future there will be an
Amplitude Prediction
option to display this information numerically.
It is also possible within the software to calculate amplitudes at positions within the
Amplitude
beam. ThisPrediction
has been done by incorporating validated beam modelling algorithms [2]
for single crystal probes. In the final application, this information, along with the
It angles
is also for
possible
within
the software
at positions
incident
the scan
will form
an input to
to calculate
some kindamplitudes
of rule. This
rule will
within
the
beam.
This
has
been
done
by
incorporating
validated
beam
modelling
consider the measure of incident angle and amplitude to decide whether the
defect is
algorithms
[2] for single
crystal
probes.
the final
application,
this information,
probably detected,
or whether
further,
moreIndetailed
modelling,
is required.
along with the incident angles for the scan will form an input to some kind of rule.
This rule will consider the measure of incident angle and amplitude to decide
whether the defect is probably detected, or whether further, more detailed
modelling, is required.
1888
(a)
(b)
(b)
*>-r—->
FIGURE 7. (a) Back projection of rays from a strip-like defect inserted into a flat plate, (b) Back
projection of rays from a circular defect inserted into a pipe.
FIGURE 7. (a) Back projection of rays from a strip-like defect inserted into a flat plate. (b) Back
projection of rays from a circular defect inserted into a pipe.
PROJECTION OF NORMAL RAYS
An additional tool to aid the engineer allows projection of normal rays from the
extremes
of a hypothetical
defect RAYS
to the inspection surfaces, to show over what extent
PROJECTION
OF NORMAL
of the scan it is possible to achieve normally incident rays on the defect. These rays
can thenAn
beadditional
interrogated
the probeallows
anglesprojection
required of
to normal
achieverays
specular
tooltotoestablish
aid the engineer
reflection
from
the
defect.
Figure
7(a)
shows
projection
of
normal
rays
from
a stripfrom the extremes of a hypothetical defect to the inspection surfaces, to show over
like
defect
inserted
into
a
flat
plate.
This
tool
may
prove
particularly
useful
what extent of the scan it is possible to achieve normally incident rays on the for
designing
inspections
components
with tocurved
surfaces,
where
therequired
normal rays
defect. These
rays canfor
then
be interrogated
establish
the probe
angles
intersect
thespecular
surface at
varying from
angles;
shows
theshows
case of
a circularofdefect
to achieve
reflection
theFigure
defect.7(b)
Figure
7(a)
projection
inserted
into afrom
pipea wall.
normal rays
strip-like defect inserted into a flat plate. This tool may prove
particularly useful for designing inspections for components with curved surfaces,
where the normal AND
rays intersect
the surface
CONCLUSIONS
FURTHER
WORKat varying angles; Figure 7(b) shows
the case of a circular defect inserted into a pipe wall.
Our plans are to expand on this work by mapping visual information to the defect
CONCLUSIONS
FURTHER
face
relating to theAND
dB-down
incidentWORK
beam amplitude achieved during the scan. We
also intend to include information regarding the location of diffraction 'glint' points on
Our plans
arewith
to expand
this workincident
by mapping
visualbeam
information
to the It is
defect edges,
along
their on
maximum
dB-down
amplitudes.
defect
face
relating
to
the
dB-down
incident
beam
amplitude
achieved
during
the that
hoped that the knowledge obtained can be used as an input to a rule base
scan.
We
also
intend
to
include
information
regarding
the
location
of
diffraction
determines whether the defect can immediately be classed as detectable or if further
‘glint’ points
on to
defect
edges,out.
along with their maximum incident dB-down beam
modelling
needs
be carried
amplitudes.
It
is
hoped
that
the
knowledge
obtained
can be used
an input tosoftware
a
In conclusion, progress has been
made in
demonstrating
thatasinteractive
rule
base
that
determines
whether
the
defect
can
immediately
be
classed
as
tools can aid the process of ultrasonic test design and Inspection Qualification. The
detectable
or ifassists
furtherthe
modelling
needs to be carried
out.
visual
display
user in understanding
the physical
reasoning of the tests. In
In
conclusion,
progress
has
been
made
in
demonstrating
that interactive
addition, the time needed to analyze the performance of a testing
procedure and
software
tools
can
aid
the
process
of
ultrasonic
test
design
and
produce evidence for the Technical Justification is greatly reduced, thusInspection
decreasing the
Qualification. The visual display assists the user in understanding the physical
cost.
reasoning of the tests. In addition, the time needed to analyze the performance of
a testing procedure and produce evidence for the Technical Justification is greatly
reduced, thus decreasing the cost.
1889
ACKNOWLEDGEMENTS
This work has been funded by the UK EPSRC, BNFL-Magnox Generation, and
British Energy Pic.
REFERENCES
1. Reilly, D., McNab A. and Toft, M., "Interactive 3-D visualisation and analysis of
NDT data in a CAD environment", Review of Progress in Quantitative Non
Destructive Evaluation, Vol. ISA, 1998, pp. 789-796.Smith, H. L. and Jones, T., J.
Appl Phys. 91, 157 (2002).
2. Coffey, J.M. and Chapman, R.K., "Application of elastic scattering theory for
smooth flat cracks to the quantitative prediction of ultrasonic defect detection and
sizing", in Nuclear Energy, 1983, 22, 5, pp. 319-333.
1890