Purpose – The purpose of the present paper is to quantify and analyze the strain-rate dependence of the yield stress for both unfilled acrylonitrilebutadiene-
styrene (ABS) and short carbon fiber-reinforced ABS (CF-ABS) materials, fabricated via material extrusion additive manufacturing (MEAM).
Two distinct and opposite infill orientation angles were used to attain anisotropy effects.
Design/methodology/approach – Tensile test samples were printed with two different infill orientation angles. Uniaxial tensile tests were
performed at five different constant linear strain rates. Apparent densities were measured to compensate for the voided structure. Scanning electron
microscope fractography images were analyzed. An Eyring-type flow rule was evaluated for predicting the strain-rate-dependent yield stress.
Findings – Anisotropy was detected not only for the yield stresses but also for its strain-rate dependence. The short carbon fiber-filled material
exhibited higher anisotropy than neat ABS material using the same ME-AM processing parameters. It seems that fiber and molecular orientation
influence the strain-rate dependence. The Eyring-type flow rule can adequately describe the yield kinetics of ME-AM components, showing
thermorheologically simple behavior.
Originality/value – A polymer’s viscoelastic behavior is paramount to be able to predict a component’s ultimate failure behavior. The results in this
manuscript are important initial findings that can help to further develop predictive numerical tools for ME-AM technology. This is especially
relevant because of the inherent anisotropy that ME-AM polymer components show. Furthermore, short carbon fiber-filled ABS enhanced anisotropy
effects during ME-AM, which have not been measured previously.
