E. Henderson, W. M. Dempster, D. H. Nash, University of Strathclyde, Glasgow, United Kingdom
Finite Element (FE) modelling is becoming the method of choice to aid faster time to market in the medical device industry. The physical relevance of the simulation is dependent on accurate geometry, material properties and correct definition of the loading regime as provided by the analyst.
When using a bio-compatible material with a complex mechanical behaviour, such as Nitinol, in the FE domain, the analyst must answer the question: “How does the reproduction of Nitinol’s material behaviour effect the accuracy and physical relevance of the FE analysis?”
The authors address this key question using the ANSYS finite element programme. By using a suitable test case, the seven characteristic parameters required for definition of the shape memory material model will be explored. Data is obtained from an experimental programme on nitinol wire used to determine the distribution and variance of each parameter from that of the constitutive relation employed. The discrepancies in the material model will then be used to determine the uncertainties in predicting the strain behaviour for the large displacement bending of a cantilever.
Summary:
The current work investigates how the variability of Nitinol’s material properties and the accuracy of the input material data affect the accuracy of a finite element model.
Summary: The current work investigates how the variability of Nitinol’s material properties and the accuracy of the input material data affect the accuracy of a finite element model.
