Influence of fatigue stress on the radial strength of polymeric braided vascular stents

2021 ◽  
Author(s):  
Hiba Jaziri ◽  
Sofiene Mokhtar ◽  
Yordan Kyosev ◽  
Nabil Chakfe ◽  
Frederic Heim ◽  
...  
Keyword(s):  
Vascular Stents ◽  
Fatigue Stress ◽  
Radial Strength

Vascular stents

1999 ◽  
Vol 36 (12) ◽  
pp. 909-1053
Author(s):  
M AMATTOS ◽  
K HODGSON ◽  
S HURLBERT ◽  
J HENRETTA ◽  
Y STERNBACH ◽  
...  
Keyword(s):  
Vascular Stents

Crush implantation of a self-expanding interwoven stent over a subintimally recanalized standard stent in a TASC D lesion of the superficial femoral artery

VASA ◽  
2012 ◽  
Vol 41 (6) ◽  
pp. 458-462 ◽  
Author(s):  
Vogel ◽  
Strothmeyer ◽  
Cebola ◽  
A. Katus ◽  
Blessing
Keyword(s):  
Femoral Artery ◽  
Superficial Femoral Artery ◽  
Popliteal Artery ◽  
Duplex Ultrasound ◽  
Stent Fracture ◽  
Nitinol Stent ◽  
Nitinol Stents ◽  
Walking Capacity ◽  
Radial Strength ◽  
Good Treatment Option

We demonstrate feasibility of implantation of a self-expanding interwoven nitinol stent in a claudicant, where recanalization attempt of a heavily calcified, occluded superficial femoral artery (TASC D lesion) was complicated by a previously implanted, fractured standard stent. Wire passage through the occlusion and beyond the fractured stent could only be achieved through the subintimal space. A dedicated reentry device was used to allow distal wire entry into the true lumen at the level of the popliteal artery. Despite crushing of the fractured stent with a series of increasingly sized standard balloons, a significant recoil remainded in the area of the crushed stent. To secure patency of the femoro-popliteal artery we therefore decided to implant the novel self-expanding interwoven nitinol stent (Supera Veritas (TM), IDEV), whose unique feature is an exceptional high radial strength. Patient presented asymptomatic without any impairment of his walking capacity at three month follow up and duplex ultrasound confirmed patency of the stent. Subintimal recanalizations can be complicated by previously implanted stents, in particular in the presence of stent fracture, where intraluminal wire passage often can not be achieved. Considering the high radial strength and fracture resistance, interwoven nitinol stents represent a good treatment option in those challenging cases and they can be used to crush standard nitinol and ballonexpandable stents.

Über die mechanische Bedeutung der Holzstrahlen | The mechanical relevance of wood rays

2003 ◽  
Vol 154 (12) ◽  
pp. 498-503 ◽  
Author(s):  
Ingo Burgert
Keyword(s):  
Beech Wood ◽  
Tensile Tests ◽  
Deciduous Tree ◽  
Biological Design ◽  
Transverse Tensile ◽  
Radial Reinforcement ◽  
Radial Strength ◽  
Transverse Tensile Strength ◽  
Strength And Stiffness ◽  
Technical Solutions

Three investigations into the mechanical relevance of wood rays were combined for this article. The main objective was to show, that, apart from physiological functions, rays also significantly influence the radial strength and stiffness of wood. In the first approach twelve deciduous tree species with various proportions of fractions of rays were examined for their transverse tensile strength and stiffness. The second approach was based on the comparison of the radial mechanical properties of wood with a very high proportion of fraction of rays and beech wood with a normal volume. In these two investigations the mechanical relevance of rays could only be deduced indirectly. By isolating big rays of beech and carrying out tensile tests on the tissue, we found direct evidence for the mechanical relevance. The results are discussed with regard to their biomechanical relevance. The importance of a radial reinforcement for the wood is underlined. Moreover, the principle of multi-functionality in nature is emphasized in keeping with a possible transfer of biological design to technical solutions.

A Multi-Dimensional Non-Uniform Corrosion Model for Bioabsorbable Metallic Vascular Stents

2020 ◽  
Author(s):  
Weiliang Shi ◽  
Hongxia Li ◽  
Kellen Mitchell ◽  
Cheng Zhang ◽  
Tingzhun Zhu ◽  
...  
Keyword(s):  
Uniform Corrosion ◽  
Vascular Stents ◽  
Corrosion Model

scholarly journals Fatigue Stress-Life Model of RC Beams Based on an Accelerated Fatigue Method

2019 ◽  
Vol 4 (2) ◽  
pp. 16
Author(s):  
Eljufout ◽  
Toutanji ◽  
Al-Qaralleh
Keyword(s):  
Cyclic Loading ◽  
Fatigue Testing ◽  
Three Dimensional ◽  
Rc Beam ◽  
Rc Beams ◽  
Testing Methods ◽  
Load Range ◽  
Fatigue Stress ◽  
Life Model ◽  
Prediction Band

Several standard fatigue testing methods are used to determine the fatigue stress-life prediction model (S-N curve) and the endurance limit of Reinforced Concrete (RC) beams, including the application of constant cyclic tension-tension loads at different stress or strain ranges. The standard fatigue testing methods are time-consuming and expensive to perform, as a large number of specimens is needed to obtain valid results. The purpose of this paper is to examine a fatigue stress-life predication model of RC beams that are developed with an accelerated fatigue approach. This approach is based on the hypothesis of linear accumulative damage of the Palmgren–Miner rule, whereby the applied cyclic load range is linearly increased with respect to the number of cycles until the specimen fails. A three-dimensional RC beam was modeled and validated using ANSYS software. Numerical simulations were performed for the RC beam under linearly increased cyclic loading with different initial loading conditions. A fatigue stress-life model was developed that was based on the analyzed data of three specimens. The accelerated fatigue approach has a higher rate of damage accumulations than the standard testing approach. All of the analyzed specimens failed due to an unstable cracking of concrete. The developed fatigue stress-life model fits the upper 95% prediction band of RC beams that were tested under constant amplitude cyclic loading.

A new design of cable anchor for ultra-high fatigue stress cable net of largest telescope in the world

2020 ◽  
pp. 107280
Author(s):  
Wanxu Zhu ◽  
Kefei Jia ◽  
Feng Fu ◽  
Dongqiu Lan ◽  
Kai Qian
Keyword(s):  
Fatigue Stress ◽  
The World ◽  
High Fatigue

scholarly journals Braided composite stent for peripheral vascular applications

2020 ◽  
Vol 9 (1) ◽  
pp. 1137-1146
Author(s):  
Qingli Zheng ◽  
Pengfei Dong ◽  
Zhiqiang Li ◽  
Ying Lv ◽  
Meiwen An ◽  
...  
Keyword(s):  
Computational Models ◽  
Surface Coverage ◽  
Mechanical Performance ◽  
Wire Diameter ◽  
Orthogonal Experimental Design ◽  
Braided Composite ◽  
Nitinol Wire ◽  
Radial Strength ◽  
Braiding Angle ◽  
The Impact

AbstractBraided composite stent (BCS), woven with nitinol wires and polyethylene terephthalate (PET) strips, provides a hybrid design of stent. The mechanical performance of this novel stent has not been fully investigated yet. In this work, the influence of five main design factors (number of nitinol wires, braiding angle, diameter of nitinol wire, thickness and stiffness of the PET strip) on the surface coverage, radial strength, and flexibility of the BCS were systematically studied using computational models. The orthogonal experimental design was adopted to quantitatively analyze the sensitivity of multiple factors using the minimal number of study cases. Results have shown that the nitinol wire diameter and the braiding angle are two most important factors determining the mechanical performance of the BCS. A larger nitinol wire diameter led to a larger radial strength and less flexibility of the BCS. A larger braiding angle could provide a larger radial strength and better flexibility. In addition, the impact of the braiding angle decreased when the stent underwent a large deformation. At the same time, the impact of the PET strips increased due to the interaction with nitinol wires. Moreover, the number of PET strips played an important role in the surface coverage. This study could help understand the mechanical performance of BCS stent and provides guidance on the optimal design of the stent targeting less complications.

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