ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
In Western countries, cardiovascular disease is the most common cause of death, oftenrelated to atherosclerosis which can lead to a narrowing of the arteries. To restore perfusion ofdownstream tissues, an intravascular stent (i.e. a small tube-like structure) can be deployed in theobstructed vessel. The vast majority of stents are balloon expandable and crimped on a foldedballoon to obtain a low profile for deliverability and lesion access. Several studies have exploitedthe finite element method to gain insight in their mechanical behaviour or to study the vascularreaction to stent deployment. However, to date – to the best of our knowledge – none of theminclude the balloon itself in its actual folded shape. Furthermore, literature on the effect of thecrimping process on the expansion behaviour of the stent is even scarcer. Our numerical results -accounting for the presence of the balloon in its actual folded shape - correspond very well with dataprovided by the manufacturer and consequently our approach could be the basis for new realisticcomputational models of angioplasty procedures. The plastic deformation, prior to the stentexpansion and induced by the crimping procedure, has a minor influence on the overall expansionbehaviour of the stent but nevertheless influences the maximum von Mises stress and nominalstrain. The maximum von Mises stress drops from 440 N/mm² to 426 N/mm² and the maximumnominal strain value lowers from 0.23 to 0.22 at the end of the expansion phase when neglecting thepresence of the residual stresses. Depending on the context in which to use the developedmathematical models, the crimping phase can be discarded from the simulations in order to speedup the analyses
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/54/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.340-341.847.pdf
