RT info:eu-repo/semantics/article
T1 Material Extrusion Additive Manufacturing of Poly(Lactic Acid): Influence of infill orientation angle
A1 Verbeeten, Wilco M.H.
A1 Lorenzo Bañuelos, Miriam
K1 PLA
K1 Angle-ply laminate configuration
K1 Anisotropic strain-rate dependent yield stress
K1 Ree–Eyring rate equation
K1 Resistencia de materiales
K1 Strength of materials
K1 Ingeniería civil
K1 Civil engineering
K1 Materiales de construcción
K1 Building materials
AB The effect that the infill orientation angle has on the strain-rate dependence of the yield stress for materialextrusion additive manufactured (ME-AM) PolyLactic Acid (PLA) material was investigated. Symmetric angleply stacking sequences were used to produce ME-AM tensile test samples. Measured yield stresses werecompensated for the voided structure, typical of ME-AM components. Furthermore, molecular orientation andstretch was macroscopically assessed by a thermal shrinkage procedure. Additionally, hot-press compressionmolded (CM) samples were manufactured and mechanically characterized in uniaxial tensile and compressionin order to determine the material’s isotropic bulk properties. Initial model parameters for the Ree–Eyringmodification of the Eyring flow rule were determined using CM data. According to SEM fractography, allsamples showed microscopically brittle fracture behavior. Notwithstanding, contrary to CM samples, ME-AMspecimens showed macroscopically ductile stress–strain behavior and a transition from a regime with onlya primary 𝛼-deformation process, at low strain rates, to a regime with 2 deformation processes (𝛼 + 𝛽), athigh strain rates. These effects are an influence of the processing step and are attributed to the molecularorientation and stretch of the polymer chains, provoking anisotropic mechanical properties. As a consequence,a deformation-induced change of the Eyring rate constants is needed to adequately describe the strain-ratedependence of the ME-AM yield stress behavior, leaving the initial activation volumes unchanged. Taking thisdeformation-dependence of the rate constants into account, yield stresses as a function of infill orientationangle can be appropriately predicted.
PB Elsevier
SN 2214-8604
YR 2022
FD 2022-11
LK http://hdl.handle.net/10259/6821
UL http://hdl.handle.net/10259/6821
LA eng
DS Repositorio Institucional de la Universidad de Burgos
RD 19-abr-2024