Biomedical

Nonlinear Hyperplastic Analysis of a Pediatric Medication Port

JAR performed a nonlinear hyperelastic axisymmetric finite element analysis of the silicone septum, cap and partitioner of a prototype medication implant device. A Mooney-Rivlin strain energy function and ANSYS hyperelastic elements were used to simulate the elastomeric material behavior of the silicone septum.
 
Static loading representing the manufacturing process was applied in prescribed increments of displacement at the boundary of the septum. Resultant boundary pressure loadings developed in the analysis of the silicone septum were then applied to the plastic enclosure structures and welds, and a stress analysis performed, to verify that the septum remained in sufficient compression to seal off the reservoir after withdrawal of the needle.

Characterization of the Expansion Properties of an Intravascular Stent

JAR analyzed the nonlinear elasto-plastic load-deflection response of an intravascular stent subjected to inflation pressure (i.e. balloon expansion) loading. Because of the instabilities that may arise during a quasi-static stent expansion process, JAR chose to use explicit dynamics finite element modeling techniques to generate the numerical solution.

Nonlinear Finite Element Analysis of Idealized Three-dimensional Model
of a Human Left Ventricle

The solid computer model of the geometry of the left ventricle was generated in this project, by superimposing actual variable (meridional) thickness data of a human left ventricle on an idealized ellipsoidal solid of revolution geometry. The endocardial surface of the left ventricle was completed by the intersection of the ellipsoidal left ventricular free wall mid-surface by a plane representing the interior surface of the ventricular septum.
 
The finite element model was first constructed using ANSYS and then later subjected to a nonlinear, large deformation, explicit dynamic finite element analysis, for end diastole pressure effects.

Additional Biomedical Projects

• Flow Optimization Analysis for an EvenFlow Infusion Catheter
   
• Geometric and Material Nonlinear Analysis of Welded Metal Bellows