Page 54 - Advances in Biomechanics and Tissue Regeneration

48 3. DESIGN, SIMULATION, AND EXPERIMENTATION OF COLONIC STENTS

The model is 3D, using BRICK- and WEDGE-type elements, with linear interpolation. Only elements that are wedge
type are used to model the groove’s corners and avoid stress concentration (Fig. 3.16).
Using just a module it is possible to determine the final shape geometry reached by truss cells, without spending a
lot of time on computation. In Fig. 3.17 we can see the curvature adopted for each truss, which conforms to the ring
spring.
Nonetheless, this reduced model is validated by comparison with previous results of a complete stent simulation,
and is found to be valid without significant loss of accuracy. Comparing deformations between Fig. 3.17 with
Fig. 3.18A we can see very similar expanded geometries and both reproduced geometries obtained by the manufactur-
ing process (Fig. 3.18B).

FIG. 3.16 General view of the simplified one-module model.

FIG. 3.17 Simulation of one stent ring cell expansion to determine configuration after the shaping process.

I. BIOMECHANICS