Mechanical characterization and modelling of the temperature-dependent impact behaviour of a biocompatible poly(L-lactide)/poly(ε-caprolactone) polymer blend.
Poly(ε-caprolactone) (PCL) is a ductile, bioabsorbable polymer that has been employed as a blend partner for poly(L-lactic acid) (PLLA). An improvement of the material strength and impact resistance of PLLA/PCL polymer blends compared to pure PLLA has been shown previously. To use numerical simulations in the design process of new components composed of the PLLA/PCL blend, a constitutive model for the material has to be established. In this work, a constitutive model for a PLLA/PCL polymer blend is established from the results of compressive tests at high and low strain rates at three different temperatures, including the body temperature. Finite element simulations of the split Hopkinson pressure bar test using the established constitutive model are carried out under the same condition as the experiments. During the experiments, the changes in the diameter and thickness of the specimens are captured by a high-speed video camera. The accuracy of the numerical model is tested by comparing the simulation results, such as the stress, strain, thickness and diameter histories of the specimens, with those measured in the experiments. The numerical model is also validated against an impact test of non-homogenous strains and strain rates. The results of this study provide a validated numerical model for a PLLA/PCL polymer blend at strain rates of up to 1800 s(-1) in the temperature range between 22°C and 50°C.
Luleå University of Technology, Division of Mechanics of Solid Materials, 971 87 Luleå, Sweden. Electronic address: gustaf.gustafsson@ltu.se.
Gustaf
G
Gustafsson
Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555, Japan.
Masahiro
M
Nishida
Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555, Japan.
Yoshitaka
Y
Ito
Luleå University of Technology, Division of Mechanics of Solid Materials, 971 87 Luleå, Sweden.
Hans-Åke
HÅ
Häggblad
Luleå University of Technology, Division of Mechanics of Solid Materials, 971 87 Luleå, Sweden.
Pär
P
Jonsén
Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.
Tetsuo
T
Takayama
Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan.
Mitsugu
M
Todo
D001672:Biocompatible Materials / Q000737:chemistry*; D020342:Finite Element Analysis; D019344:Lactic Acid / Q000737:chemistry*; D055595:Mechanical Phenomena; D008958:Models, Molecular; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013314:Stress, Mechanical; D013696:Temperature
D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; D019344:Lactic Acid; C033616:poly(lactide)
Constitutive model; Finite element method; PCL; PLLA; Split Hopkinson pressure bar; Temperature dependency