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Research Programmes
Polymers comprise a wide range of natural and synthetic
materials. The demand for polymers has increased
considerably during the last few decades. Applications include
safety-related parts in cars, coatings, thermal insulation in
offshore components, seals and inter-glass layers in laminated
windows. The finite element method has only rather recently
become a relevant tool in the design process of parts made
of polymers. Therefore, constitutive models for such materials
are less mature than for metals. Prediction of fracture is also
a topic of interest for research and industry. Knowledge about
the physical mechanisms governing the thermo-mechanical
behaviour is of utmost importance for successful development
of material models. The main objective of the Polymeric
Materials research programme is to develop and improve
material models representing the thermo-mechanical response
up to fracture for polymers. The models will be developed for
application in an industrial context. Particular attention is paid
to validation and efficient identification of the parameters
involved in the models. Actual materials include commodity
thermoplastics (like PE and PP, commonly reinforced with
small mineral and/or rubber particles), fibre-reinforced
thermoplastics, elastomers and foams made of polymers.
The large-strain response of ductile thermoplastics has been
the topic of Marius Andersen’s PhD project. He finished his
thesis in early 2016. It contains work on the development
of robust methods for experimental characterization as well
as a constitutive model that is able to represent the stress-
strain curve at different strain rates and temperatures.
Directly financed by Aker Solutions in an affiliated project,
Arne Ilseng also delivered his PhD thesis in 2016. His topic
was the behaviour of elastomers at different temperatures.
He applied a transparent chamber made of polycarbonate, see
Figure 7, in his research. It was connected to a supply of liquid
nitrogen, allowing for material testing at low temperatures in
combination with instrumentation involving digital cameras.
This chamber has also been applied in other studies.
Ongoing PhD projects comprise Petter Henrik Holmstrøm who
is working on the modelling of fibre-reinforced thermoplastics,
and Sindre Olufsen, who is studying ductile failure. In
addition to mechanical tests, computer tomography (CT)
is an important tool in both projects in order to improve the
understanding of the deformation mechanisms to capture
in the material models. New PhD candidates from August
2016 are Jon Eide Pettersen and Daniel Morton, who are
respectively working on viscoelastic behaviour and foams.
The interaction with the industrial partners engaged in the
Polymeric Materials programme is maintained through annual
technical meetings. One such meeting was arranged in
Trondheim in November 2016, and gathered Audi, BMW, DNV
GL, Statoil and Toyota. The partners addressed their research
needs at these meetings, and provided valuable advice for
future research activities.
Figure 7: Experimental set-up for material tests at low temperatures.
Polymeric Materials
Head of Programme: Arild Holm Clausen
1. Specimen
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2. Specimen
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3. Camera 1
4. Camera 2
5. IR camera
6. LN2 container
7. PC chamber
8. Table top fan
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