JEC COMPOSITES MAGAZINE - Issue #104 - April/May 2016 - 43

Fig. 4: Pre-release trialling of Imetrum's crack length gauge technology for
double cantilever beam (DCB) testing at ACCIS, University of Bristol

"The Imetrum crack-tracking software is a game-changing
product for researchers investigating the fracture mechanics of
Mode I double cantilever beam (DCB) test specimen coupons
(figure 4). For what was once a laborious, time-consuming and
non-automated process to correlate crack length with failure
load and displacement, this technology enables the output of
these test data values into a simple text file.... I would highly
recommend this system to researchers conducting this test due
to the simplicity of the setup."

Fig. 3: Pre-release trialling of Imetrum's frame mounted video extensometer

the high fatigue loading intensity, which was near the static
failure strength of the healing resin. However, the potential
for ameliorating (via self-healing or autonomous repair) more
diffuse transverse matrix damage via a vascular network has
also been shown.
The team at ACCIS are continuing their work to improve the
self-healing approach, encouraged both by the early promise
and the potential benefit of the technique. Their latest EUfunded research project, HIPOCRATES [3], builds upon this
progress to realise vascular-based self-healing technologies in
industrially relevant aerospace demonstrator concepts, such as
stringer run-out test specimens. They will also continue to use
Imetrum's systems, investing in new equipment as they progress
(the team at Bristol currently has three UVX Flexi video extensometers, figure 3). One potential future investment would be
the inclusion of Imetrum's newly launched crack length gauge
into their existing systems. This gauge is the first of its kind
in the world, and has received a glowing review from Dr Tim
Coope:

To conclude, the benefits of this type of self-healing approach
are highlighted by the research's ability to realise multiple healing events. While there are many challenges when deploying
self-healing into structural applications, evidence shows that
composite materials can recover from damage events by introducing a healing agent through a vascular network. n
References
[1] Luterbacher R., Trask R. S. and Bond I. P. Self-healing of
skin-stiffener debond specimens under fatigue conditions. 20th
International Conference on Composite Materials Copenhagen,
July 2015
[2] Luterbacher R., Trask R. S. and Bond I. P. Static and fatigue
tensile properties of cross-ply laminates containing vascules
for self-healing applications. Smart Mater. Struct., 25, (2016),
015003
[3] HIPOCRATES (self-HealIng POlymers for Concepts on selfRepaired Aeronautical composiTES) is a collaborative project
co-funded by the 7th Framework Programme of the European
Community (605412)

More information:
www.accismultifunctional.com
www.imetrum.com

No104 April - May 2016 /

jec composites magazine 43

http://www.accismultifunctional.com http://www.imetrum.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #104 - April/May 2016