Abstract: The foundational theory of large plastic deformation and contact algorithm for finite element numerical analysis of stent coupling expansion are studied. Based on the principle of virtual power, the finite element formulation for the dynamic explicit analysis of stent coupling expansion and the solving process were presented by using updated Lagrangian method. The key technologies of numerical simulation for stent coupling expansion are studied. The finite element modeling method adapting to stent coupling expansion is proposed. The key issues including geometry modeling, materials selection, meshing, boundary conditions, loads definition, and contact disposal are studied. Moreover, a sample of tubular coronary stent was expanded on the testing platform and its testing data in the experiment were analyzed compared with the result of numerical simulation. The experimental result showed that the error, between numerical simulation and the expansion experiment are in the permission spectrum. Consequently, the 3D numerical analysis method for stent coupling expansion is proved reasonable, and provided a powerful support for the stent optimization design and finite element simulation of stent expansion.

Key words: Coupling expansion, Invitro experiment, Numerical simulation, Vascular stent