Stent Expansion, Shape Setting, and Crimping — Lesson 4

We learned that stents are manufactured with a diameter that is larger than the vessel diameter, but the larger the tube diameter the more expensive the manufacturing cost. Stents typically have been cut from smaller diameter tubes and expanded to the desired diameters. They are then annealed to set the shape.

After stent expanding and shape setting, it is then crimped to a smaller diameter to fit in the delivery mechanism. Stent expansion, shape setting and crimping are important steps — so important that the FDA mandates the use of simulation for these processes to evaluate stents.

 

 

In these lessons, we will learn how to replicate the stent expanding, shape setting and crimping process in Ansys simulation.

Stent Expansion Geometric Setup and Material Definition Workshop

The simulation files for this workshop can be found here.

  • Please note that this is the only file required to start the workshop. Each of the subsequent workshops successfully builds upon the completion of the previous workshop.
  • Please utilize the mm, kg, N unit system when solving the Ansys simulation models.
  • Please also note that the results you obtain in these nonlinear analyses may differ slightly from those shown in the videos. Numerical round-off due to finite machine precision can be affected by the choice of the operating system, the number of cores, and the type of parallel processing (shared-memory vs. distributed-memory). Moreover, nonlinear contact and solution algorithms are often improved in each version of our software, so some changes are expected when comparing results between different releases. Thus, your results may differ slightly (within typical engineering tolerances) from the presented results, but this is to be expected for nonlinear analyses, especially for numerically unstable (e.g., underconstrained) models that may be utilized in this course.

Setup Expansion Boundary Conditions and Start of Simulation Workshop

Stent Expansion Results Evaluations Workshop

Shape Setting and Initial Setup of Crimp Workshop

Crimping of Stent and Results Evaluations Workshop

Completed simulation files for the above examples can be found here

 

Handout