ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

ox in Fig. 7, are the nearest to the limit curve and so they have the high risk of fracture.
4. CONCLUSIONS
From the computational simulation the following results were obtained:
i) the cyclic axial pressure is the less critical loading condition; regarding the maximum
values of εa, it is evident that the strain induced by cyclic pressure is one order lower
than the strain induced by axial compression (0.031% vs. 0.25%).
ii) the non-uniform longitudinal and radial thickness of vessel-plaque system influences
the location of the most stressed zones of the stent, that undergoes a higher loading in
relation to the low radial and axial stiffness of the vessel-plaque wall.
iii) the distribution of pairs of values on the constant-life diagram for different plaque
shapes depends on plaque features: it has been found that a double peak plaque is the
most critical configuration because the most stressed zones are nearest to the limit curve
than in other cases.
Only a complex computational model that takes into account vessel and plaque features
could be useful in predicting the fatigue resistance of the device. However, in order to
predict correctly the risk of failure of the device under cyclic loading conditions, a
fatigue characterization of the stent material should be performed.
5. AKNOWLEDGMENT
This work is within the project ''RT3S - Real Time Simulation for Safer vascular
Stenting'' partially funded by the European Commission under the 7th Framework
Programme, GA FP7-2009-ICT-4-248801
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