JEC COMPOSITES MAGAZINE - Issue #83 - August/September 2013 - 70

NDT
codes include instructions on where
to move, how fast to move, and what
path to follow. In essence, the system
becomes a machine tool. Therefore,
machining technology is embraced
without performing manufacturing.
For example, Figure 2 shows a practical
implementation of a system that is using the above technology to automatically plan, load, inspect and unload
composite parts. This is what is loosely
called a CAD/CANDT system.

investment of time up front during preproduction planning. The payoff is that
the NDT system cycle is much faster
because the machine utilization is fully
dedicated to inspection.
- Training: NDT personnel are inexperienced in the use of machine codes.
In the same way that machinists have
learned to interpret and use these tools
to their benefit, NDT personnel must
be trained to use these tools effectively
for inspection.

Integration challenges

CAD/CANDT has the potential to
eliminate some of the inefficiencies
that arise from the way NDT is currently being implemented into production. Some questions the NDT community must ask themselves include:

Integrating multiple technologies into
a single system is a complex and challenging operation. Learning how to
make effective use of existing CAD/
CAM technologies and adapting them
to NDT requires some planning, as
processes are different. A machining
program, by definition, does everything from the front surface. In NDT,
however, what goes inside the material has to be controlled. For example,
when inspecting a radius, the coverage
of the back surface is quite different
than what is seen from the front surface. Therefore, the ultrasonic physical phenomena need to be taken into
consideration when planning the scan
plan. The challenges faced include:
- Limited familiarity with multiple disciplines: CAD/CAM technicians and
engineers are not usually proficient in
NDT. Similarly, NDT personnel are
not typically familiar with CAD intricacies. This is a major stumbling block
in technology integration. It can be
difficult to exchange information and
communicate when each party does
not understand the other party’s field
of competence.
- Software: NDT is a niche sector, and
not the primary market for standard CAD/CAM software packages.
Although these packages typically have
inspection tools, they were not part of
the developer’s original focus, making
NDT customization more difficult. It
is, however, still doable.
- Time: Successfully incorporating
beneficial technology requires an

- Is NDT being considered as part of
the design process to facilitate inspectability?
- Is the inspection machine time used
efficiently?
- Why is it that the tool paths for
machining are done by the CAM office
whereas inspection tool paths (scan
plans) are done by NDT personnel?

- Why are we using the inspection system to simulate inspection rather than
using commercially available software
commonly used for machine tools?
Functionally, integration requires looking closely at the points of failures/
weaknesses of the system. Technologies can work together, to the benefit
of all, if CAD, CAM and NDT personnel are working in closer cooperation.
To perform effectively, a manufacturer
needs its teams to operate as a unified
group, working towards common business goals, sharing information about
the tools that are used. NDT cannot
and should not operate in isolation.

Ultrasonic inspection
Composite parts inspected using the
immersion system represented in
Figure 2 have complex 3D shapes and
include tight radii. Inspection of these
parts using a conventional phased-array approach requires a combination of
curved and flat probes. The approach
is illustrated in the top row of Figure 3
for a hat-section stringer where linear
and curved arrays have been optimized

Fig. 3: Three phased-array solutions for inspecting a hat-section stringer

70 jec composites magazine / No83 August - September 2013

JEC COMPOSITES MAGAZINE - Issue #83 - August/September 2013

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #83 - August/September 2013