Continuum Mech. Thermodyn. (2017) 29:1093–1111
· T. Scheffer · S. Diebels
Mechanical characterization of a short ﬁber-reinforced
polymer at room temperature: experimental setups
evaluated by an optical measurement system
Received: 16 August 2016 / Accepted: 13 February 2017 / Published online: 27 February 2017
© Springer-Verlag Berlin Heidelberg 2017
Abstract Composite materials are of great interest for industrial applications because of their outstanding
properties. Each composite material has its own characteristics due to the large number of possible combi-
nations of matrix and ﬁller. As a result of their compounding, composites usually show a complex material
behavior. This work is focused on the experimental testing of a short ﬁber-reinforced thermoplastic composite
at room temperature. The characteristic behavior of this material class is often based on a superposition of
typical material effects. The predicted characteristic material properties such as elasto-plasticity, damage and
anisotropy of the investigated material are obtained from results of cyclic uniaxial tensile tests at constant strain
rate. Concerning the manufacturing process as well as industrial applications, the experimental investigations
are extended to multiaxial loading situations. Therefore, the composite material is examined with a setup close
to a deep-drawing process, the Nakajima test (Nakazima et al. in Study on the formability of steel sheets.
Yawate Technical Report No. 264, pp 8517–8530, 1968). The evaluation of the experimental investigations
is provided by an optical analysis system using a digital image correlation software. Finally, based on the
results of the uniaxial tensile tests, a one-dimensional macroscopic model is introduced and ﬁrst results of the
simulation are provided.
Keywords Composite material · Short ﬁbers · Optical deformation measurement · Plasticity · Nakajima test
Composite materials are of upcoming interest for many industrial applications. One of the main reasons of
interest is their lightweight character. For reasons of economy and ecology, especially the big sectors of
automotive and aviation industry have high ambitions to produce cost-effectively and without non-renewable
materials. Hence, composite materials consisting of a matrix material and additional ﬁller particles, inﬂuencing
the material’s behavior, represent an efﬁcient construction material for many applications. Very often the pure
matrix material, e.g., a polymer, does not fulﬁll the industrial requirements concerning stiffness and strength.
However, the desired properties can be obtained by adding a second component, such as glass ﬁbers, to the
applied material. Often, composite materials are a good alternative to metals in terms of material properties.
Polymeric matrix composites are analyzed in some current works with respect to the fatigue and fracture
behavior [4,16,35,36] as well as anisotropy . An improvement of the experimental procedure of uniaxial
tensile tests, which are commonly used in experimental works [12,19,25], will be experimental investigations
under multiaxial loading situations and evaluations with an optical deformation measurement system. The
possible combinations within the class of polymeric matrix composites are manifold. Glass, carbon or natural
Communicated by Andreas Öchsner.
C. Röhrig (
) · T. Scheffer · S. Diebels
Lehrstuhl für Technische Mechanik, Universität des Saarlandes, Campus, Geb. A4.2, 66123 Saarbrücken, Germany