4D Numerical Analysis of Scaffolds: A New Approach - Tissue Engineering: Computer Modeling, Biofabrication and Cell Behavior - page 83

Fig. 7 Normalized:
(a) strength and (b) molecular
weight, for different
degradation time of
PLA-PCL fibers, of 150 µm
and 400 µm, under PBS

Fig. 8 Normalized: (a) mass,
(b) molecular weight and
strength, for different
degradation time of
PLA-PCL fibers, of 400 µm,
under PBS

seen in Fig. 9 and in Table 1 . This same trend can be found in the degradation results
of other previous works, such as the one by Meek et al. [ 28 ], with PDLA-PCL. This
can therefore provide a strategy to obtain a design failure criterion for the evolution
of the limit strength of the device during the degradation process, σ = f(t) .

9 Constitutive Models to Simulate Mechanical Behavior During
Hydrolytic Degradation

Whenever loading conditions are simple and the desired lifetime of mechanical sup-
port is known, a “trial and error” approach may be sufficient to design reasonable
reliable devices. In more complex situations, scaffolds designers can use numerical
approaches to define the material formulation and geometry that will satisfy the im-
mediate needs of symptomatic relief. In these cases, they can use constitutive models
supplied in the commercial packages of Finite Element Method (FEM) modeling,
to simulate the mechanical behavior of a device in the most severe condition, based