摘要：Bioengineering and biomechanics are areas of growing interest in the scientific
and engineering research community. Computational biomechanics is a
relatively new discipline in which scientists pretend to use computational
and mathematical tools to model and predict biomechanical events and
phenomena using the finite element method as a primary tool. In this context,
appropriate selection, development and robust implementation of constitutive
models for biological tissues and biomaterials seems to be a challenging
task. The role of constitutive models is crucial to achieve realistic
numerical simulations. A highly popular material for biomedical applications is
UHMWPE (ultra high molecular weight polyethylene). UHMWPE is a though
material with the highest impact strength of any thermoplastic ever made, on
the other hand, it is quite difficult to find a constitutive model capable to
reproduce all the phenomenological features that can be observed in simple
uniaxial tests of this material . Recent publications show that the
Arruda-Boyce constitutive model is capable to reproduce the mechanical
behavior of UHMWPE quite accurately. While the Arruda-Boyce viscoplastic
constitutive model is quite popular in the area polymer mechanics there are
not much works referring to its computational implementation. The physically
inspired mathematical structure of Arruda-Boyce viscoplastic model offers a
few particularities that make its mathematical treatment and
numerical implementation quite difficult. With the awareness of the potential
drawbacks and inconveniences that can be found in the numerical
implementation of this constitutive model, a simple implementation of the
Arruda-Boyce constitutive model is presented in this work. The implementation is
done by means of a explicit integration algorithm coded in a UMAT subroutine
for ABAQUS finite element software
