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Page 4 of 13 Kumar et al. Vessel Plus 2019;3:35 I http://dx.doi.org/10.20517/2574-1209.2019.006

Table 1. Mechanical properties of PEEK 450G biomaterial [15]
Material Properties
Material 3
Modulus of Elasticity E in (MPa) Density ρ in (kg/mm ) Poisson’s Ratio υ Yield Stress σy in (MPa)
PEEK 450G 3700 1.30 × 10 -6 0.36 100
PEEK: polyether ether ketone

Balloon
[14]
Geometrical illustration of balloon model was formed based on standard reference . The length of
the balloon was 25 mm and as a medium to inflate the coronary stent. The balloon thickness and outer
diameter were 0.05 mm and 1.79 mm. To signify the balloon a polyurethane rubber form material was
used. The balloon was modeled by using Mooney-Rivlin hyper elastic strain energy potential “W” and
polyurethane is incompressible. Like coronary stent, the element type used for modeling of balloon in
ABAQUS as M3D8R (linear 8-noded membrane element). The FE model of the balloon consisted of 13,750
elements 13,805 nodes.

Vessel
The model of vessel was created by assuming of isotropic and homogeneous material. The vessel was
modeled by using hyper elastic Ogden material behavior and as a one- layer blood vessel. The vessel length
was 23 mm, vessel outer diameter was 5 mm, and vessel thickness was 0.5 mm. The element type used
for modeling of vessel in ABAQUS was C3D8R (linear 8-noded solid element). The FE model of the vessel
consisted of 2352 elements, and 111,692 nodes.

Plaque
There are two types of plaque generated in coronary artery, viz., hypo-cellular and calcified plaque. The
hypo-cellular type was used for the modeling of plaque. Geometrical parameters used for the plaque are
as follows. Length of plaque = 10 mm, outer diameter of plaque = 4 mm, and thickness of plaque = 1 mm.
Element type used for modeling of plaque in ABAQUS was C3D8R (linear 8-noded solid element). The FE
model of the plaque consisted of 21,030 elements and 125,390 nodes

Non-linear bending analysis
The bending of coronary stent implant has both limitations and advantages. On one side, bending of
coronary stent produces elevated stresses on coronary artery; due to these high stresses vessel damage
might occur. On other side, the coronary stent bending can facilitate to keep coronary stent steady against
the force of pulsate movement of blood. Hence the bending analysis in coronary stent implant can be
extremely helpful to alter design of coronary stents. In this article only cardiovascular stent is considered
for bending analysis.

Materials properties
In this study, the assumption was made that the PEEK 450G biomaterial was homogenous and isotropic
characterized by four material properties, i.e., Modulus of elasticity, Density, Poisson’s ratio and Yield
stress. The mechanical properties of PEEK 450G biomaterial are represented in the Table 1 .
[15]

Loading and constraints
Based on numerical data for biomedical stent using PEEK 450G biomaterial the deformation of the stent in
terms of bending which is dealt as four different loading cases as shown in Table 2 and also the one end
[16]
of the stent is fixed in all DOF.

Analysis
Finite element analysis solver ABAQUS V6.10 was used to find out von-mises stresses of PEEK 450G stent
at various loading cases, i.e., 1 mm displacement in Y direction, 2 mm displacement in Y direction with 0.1