Mechanical property analysis of Nitinol defective stent under uniaxial loading/unloading

Zhi, Yinglin; Wang, X.M.; Gao, Zongzhan; Liu, Y.S.; Yue, Zengji

doi:10.1002/mawe.200800274

Cited by 5 publications

(3 citation statements)

References 14 publications

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“…This is in good agreement with previous results on laser-cut stents, where it was observed that TiC particles can act as microcrack initiation sites [11]. It was also found that a stent is more likely to fail if these particles are situated close to geometrical knots and notches [18]. Figure 13b suggests that such cracks can link up during cyclic mechanical loading and form bigger cracks.…”

Section: Surface Inspection Of Braided Stentssupporting

confidence: 86%

Processing and characterization of braided NiTi microstents for medical applications

Frotscher¹,

Schreiber

Neelakantan

et al. 2011

Materialwissenschaft Werkst

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In the present exploratory study we investigate the processing of NiTi microstents, which were produced by braiding. We give a short description of the braiding of microstents using 0.1 mm pseudoelastic NiTi wires. We compare our braided microstents with microstents which were produced, using the traditional tube making and laser cutting technology. We outline why braiding may avoid some of the inherent problems related with the traditional procedure and highlight its cost effectiveness. We report on the thermal, chemical and mechanical properties of braided microstents. Most importantly, we provide information on the elementary damage processes which characterize displacement controlled fatigue loading up to 30 N 10 6 cycles. The results presented in this work provide information on a research field, which links the engineering manufacturing field braiding (as a potential new processing technology for NiTi stents) with state-of-the-art materials science techniques for the characterization of pseudoelastic NiTi shape memory alloys.

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Section: Surface Inspection Of Braided Stentssupporting

confidence: 86%

Processing and characterization of braided NiTi microstents for medical applications

Frotscher¹,

Schreiber

Neelakantan

et al. 2011

Materialwissenschaft Werkst

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“…Fig. 1(f) shows the geometry of a common stent (Zhi et al, 2008). The mesh elements are filleted at the blending points, where their tangent changes continuously.…”

Section: Lattice Cells With Smooth Shape Elementsmentioning

confidence: 99%

“…For example, Fig. 1(f) shows the structural geometry of a recent stent consisting of a 2D lattice of closed cells (Zhi et al, 2008). At the blending points between the arcs and the linear segments of each cell, the curvature is not smooth.…”

Section: Introductionmentioning

confidence: 98%

Shape optimization of stress concentration-free lattice for self-expandable Nitinol stent-grafts

Abad

Pasini

Cecere

2012

Journal of Biomechanics

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In a mechanical component, stress-concentration is one of the factors contributing to reduce fatigue life. This paper presents a design methodology based on shape optimization to improve the fatigue safety factor and increase the radial stiffness of Nitinol self-expandable stent-grafts. A planar lattice free of stress concentrators is proposed for the synthesis of a stent with smooth cell shapes. Design optimization is systematically applied to minimize the curvature and reduce the bending strain of the elements defining the lattice cells. A novel cell geometry with improved fatigue life and radial supportive force is introduced for Nitinol self-expandable stent-grafts used for treating abdominal aortic aneurism. A parametric study comparing the optimized stent-graft to recent stent designs demonstrates that the former exhibits a superior anchoring performance and a reduction of the risk of fatigue failure.

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Analysis of the compression process and dimensional optimization of self‐expanding stent of a nickel titanium alloy

Wang¹,

Zhou

Liu

et al. 2012

Materialwissenschaft Werkst

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The vascular stents are important devices introduced into the vessel to protect the lumen from unfriendly stenosis so that the blood can flow naturally. During its implantation to the vessel, the stent should be compressed to a delivery system with very small dimension to accomplish the minimal invasive operation. At this stage, the stent will withstand very large stresses which will cause large damages in the structure. In this paper, the compression process of the stent was analyzed by finite element analysis method with software ABAQUS. The stress, strain and martensite volume fraction distributions were investigated at the end compression. Results show that the stent fillets are the dangerous areas for the potential failure. Subsequently, the dimensional optimization was performed to decrease the maximum concentration stress. After the optimization, the maximum stress can be decreased by 14.2%, which means the stent's work life can be increased.

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Mechanical property analysis of Nitinol defective stent under uniaxial loading/unloading

Cited by 5 publications

References 14 publications

Processing and characterization of braided NiTi microstents for medical applications

Processing and characterization of braided NiTi microstents for medical applications

Shape optimization of stress concentration-free lattice for self-expandable Nitinol stent-grafts

Analysis of the compression process and dimensional optimization of self‐expanding stent of a nickel titanium alloy

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