Numerical Study of the Plasticity-Induced Stabilization Effect on Martensitic Transformations in Shape Memory Alloys

It is well-known that plastic deformations in shape memory alloys stabilize the martensitic phase. Furthermore, the knowledge concerning the plastic state is crucial for a reliable sustainability analysis of construction parts. Numerical simulations serve as a promising tool for the realistic investigation of the complex interactions between phase transformations and plastic deformations. An implementation of an appropriate material model into commercial finite element programs, e.g. Abaqus, offers the opportunity to analyze entire structural components at low costs and fast computation times.

In our talk, we begin with the presentation of the extension of an energy-based material model for shape memory alloys by plastic deformations. All model parameters are physically well-defined and easy to measure. After the model derivation and calibration, we discuss numerical issues of the implementation into a finite element routine. Afterwards, we show numerical results for Nitinol endovascular devices as an industrial example. To this end, we apply a complex thermo-mechanical (post-processing) load history, i.e. contact and thermo-mechanical loads, and compare the respective results to experiments.