Finite element analysis of the mechanical performance of a zinc alloy stent with the tenon-and-mortise structure

2021 ◽  
pp. 1-9
Author(s):  
Sirui Wang ◽  
Dandan Wu ◽  
Gaoyang Li ◽  
Kun Peng ◽  
Yongliang Mu ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
3D Models ◽  
Zinc Alloy ◽  
The Novel ◽  
Element Analysis ◽  
Novel Structure ◽  
Closed Ring ◽  
Alloy Material ◽  
Biodegradable Stents ◽  
Novel Design

BACKGROUND: Inadequate scaffolding performance hinders the clinical application of the biodegradable zinc alloy stents. OBJECTIVE: In this study we propose a novel stent with the tenon-and-mortise structure to improve its scaffolding performance. METHODS: 3D models of stents were established in Pro/E. Based on the biodegradable zinc alloy material and two numerical simulation experiments were performed in ABAQUS. Firstly, the novel stent could be compressed to a small-closed ring by a crimp shell and can form a tenon-and-mortise structure after expanded by a balloon. Finally, 0.35 MPa was applied to the crimp shell to test the scaffolding performance of the novel stent and meanwhile compare it with an ordinary stent. RESULTS: Results showed that the novel stent decreased the recoiling ratio by 70.7% compared with the ordinary stent, indicating the novel structure improved the scaffolding performance of the biodegradable zinc alloy stent. CONCLUSION: This study proposes a novel design that is expected to improve the scaffolding performance of biodegradable stents.

A NOVEL STRUCTURE DESIGN OF BIODEGRADABLE ZINC ALLOY STENT AND ITS EFFECTS ON RESHAPING STENOTIC VESSEL

2020 ◽  
Vol 20 (06) ◽  
pp. 2050022
Author(s):  
KUN PENG ◽  
AIKE QIAO ◽  
JUNJIE WANG ◽  
MAKOTO OHTA ◽  
XINYANG CUI ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Structure Design ◽  
Zinc Alloy ◽  
Challenging Problem ◽  
Element Analysis ◽  
Novel Structure ◽  
Biodegradable Stents ◽  
The Common ◽  
Alternative Choice ◽  
Stenotic Vessel

Biodegradable zinc alloy stents offer a prospective solution to mitigate incompatibility between artery and permanent stents. However, biodegradable stents are restricted in clinical therapy mainly because of their insufficient support for opening of stenotic vessel. As an effort to resolve this challenging problem, a novel structure of zinc alloy stent which significantly enhanced scaffold performance is proposed in this paper. Subsequently, the functionality of the new stent on reshaping vessels with 40% of stenosis was investigated in contrast with a common stent via finite element analysis. The simulation results show that radial recoiling ratio and dog-boning ratio of the new stent are decreased by 43.2% and 16.3%, respectively, compared with those of the common stent. A larger and flatter lumen is found in the plaque-vessel system deployed with the new stent. It suggests that the geometry of stent has strong influence on its mechanical performance. With strong scaffold capability and brilliant effect on reshaping stenotic vessel, the biodegradable zinc alloy stent-based novel structure is highly promised to be an alternative choice in interventional surgeries.

Design and Analysis of a New Mechanism for a Snake Like Robot

2020 ◽  
Author(s):  
Johnathon Garcia ◽  
Kooktae Lee
Keyword(s):  
Power Loss ◽  
Robot Design ◽  
The Novel ◽  
Loss Minimization ◽  
Positive Power ◽  
Unit Distance ◽  
Novel Structure ◽  
3D Printed ◽  
Numerical Minimization ◽  
Novel Design

Abstract In this paper, a novel snake like robot design is presented and analyzed. The structure described desires to obtain a robot that is most like a snake found in nature. This is achieved with the combination of both rigid and soft link structures by implementing a 3D printed rigid link and a soft cast silicone skin. The proposed structure serves to have a few mechanical improvements while maintaining the positives of previous designs. The implementation of the silicone skin presents the opportunity to use synthetic scales and directional friction. The design modifications of this novel design are analyzed on the fronts of the kinematics and minimizing power loss. Minimization of power loss is done through a numerical minimization of three separate parameters with the smallest positive power loss being used. This results in the minimal power loss per unit distance. This research found that the novel structure presented can be effectively described and modeled, such that they could be applied to a constructed model.

Finite Element Analysis of Mechanics Property on Memory Alloy Patella Claws with Anti-Shearing Force

2014 ◽  
Vol 635-637 ◽  
pp. 507-510
Author(s):  
Dong Peng Du ◽  
Zhe Wu ◽  
Juan Xing ◽  
Xiao Yan Gong ◽  
Xiang Wen Miu ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Mechanical Performance ◽  
Tensile Force ◽  
Research Result ◽  
Element Model ◽  
3D Models ◽  
Shearing Force ◽  
Maximum Displacement ◽  
Element Analysis

When strong exercise on human being body, respectively, under knees 30°, 60°,90°, using PRO/E5.0 software to establish the transverse patella fracture and anti-shearing force patella claws 3D models, then the two structure models were assembled and imported into ABAQUS10.1 software to establish the finite element model of patellar fracture fixed within patella claw, and analyzed the mechanical performance in perforce finite element model. Under the same boundary conditions, the maximum displacement and deformation of each components were different at every flexion angle. Compared with anti-shearing force patella claw and AO tensile force girdle, the patella claw with stronger resistance to tension and anti-shearing force was more stable. Deformation and displacement of patella claw in accordance with biomechanical research result that is needed by clinical. Its stability will satisfy clinical requirements for functional exercise.

Finite Element Modeling of Biodegradable Stents

2013 ◽  
Author(s):  
Nic Debusschere ◽  
Matthieu De Beule ◽  
Peter Dubruel ◽  
Patrick Segers ◽  
Benedict Verhegghe
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Mechanical Performance ◽  
Cost Effective ◽  
Minimal Invasive ◽  
Material Behavior ◽  
Element Analysis ◽  
Design And Optimization ◽  
Stent Restenosis ◽  
Biodegradable Stents

Biodegradable stents, which temporarily support a stenotic blood vessel and afterwards fully disappear, have recently gained a lot of interest. They avoid long-term complications associated with conventional stents such as late stent thrombosis and in-stent restenosis. Moreover, degradable stents allow for a restoration of vasomotion and vessel growth which makes them particularly suitable for pediatric applications [1]. Finite element simulations have proven to be an efficient and cost-effective tool to investigate and optimize the mechanical performance of minimal invasive devices such as stents [2]. Biodegradable stents have however created new challenges in their design and optimization via finite element analysis because of their complex time-varying material behavior. To correctly simulate the mechanical behavior of biodegradable stents, a model should be developed that incorporates the effect of degradation upon all material characteristics. By combining existing constitutive material models based on continuum damage theory we were able to create such a virtual environment in which the transitional mechanical behavior of biodegradable stents can be investigated.

Innovative Design and Simulation for a Novel Vane Pump

2011 ◽  
Vol 328-330 ◽  
pp. 354-359
Author(s):  
Shi Biao Huang
Keyword(s):  
Finite Element Analysis ◽  
Optimized Design ◽  
The Novel ◽  
Analysis Software ◽  
Vane Pump ◽  
Element Analysis ◽  
Innovative Design ◽  
Novel Structure ◽  
Simulating Analysis ◽  
New Type

A novel structure of vane pump is brought forward, a new assembly relation among vane, sleeve, port plate and stator is created, mechanical bearing condition of new-type vane is preferable than traditional vane, vane is kept clearance with stator all the time as long as dimensions of those parts are reasonable. Modal analysis and optimized design for vane is made with finite element analysis software ANSYS. By simulating analysis for pump, simulation result shows that this novel vane pump is feasible. Compared with traditional pump, wear and vibration of novel vane pump can be reduced, volumetric efficiency of pump can be enhanced remarkably, the novel vane pump has certain application value.

Computational Modeling of the Mechanical Performance of a Magnesium Stent Undergoing Uniform and Pitting Corrosion in a Remodeling Artery

2017 ◽  
Vol 11 (2) ◽  
Author(s):  
Enda L. Boland ◽  
James A. Grogan ◽  
Peter E. McHugh
Keyword(s):  
Magnesium Alloy ◽  
Computational Modeling ◽  
Pitting Corrosion ◽  
Mechanical Performance ◽  
Formation Rate ◽  
The Body ◽  
Neointimal Formation ◽  
Modeling Framework ◽  
Element Analysis ◽  
Biodegradable Stents

Coronary stents made from degradable biomaterials such as magnesium alloy are an emerging technology in the treatment of coronary artery disease. Biodegradable stents provide mechanical support to the artery during the initial scaffolding period after which the artery will have remodeled. The subsequent resorption of the stent biomaterial by the body has potential to reduce the risk associated with long-term placement of these devices, such as in-stent restenosis, late stent thrombosis, and fatigue fracture. Computational modeling such as finite-element analysis has proven to be an extremely useful tool in the continued design and development of these medical devices. What is lacking in computational modeling literature is the representation of the active response of the arterial tissue in the weeks and months following stent implantation, i.e., neointimal remodeling. The phenomenon of neointimal remodeling is particularly interesting and significant in the case of biodegradable stents, when both stent degradation and neointimal remodeling can occur simultaneously, presenting the possibility of a mechanical interaction and transfer of load between the degrading stent and the remodeling artery. In this paper, a computational modeling framework is developed that combines magnesium alloy degradation and neointimal remodeling, which is capable of simulating both uniform (best case) and localized pitting (realistic) stent corrosion in a remodeling artery. The framework is used to evaluate the effects of the neointima on the mechanics of the stent, when the stent is undergoing uniform or pitting corrosion, and to assess the effects of the neointimal formation rate relative to the overall stent degradation rate (for both uniform and pitting conditions).

Development and Optimization of the Bridge-Lever-Type Hinge Mechanisms

2018 ◽  
Author(s):  
Fangxin Chen ◽  
Futian Gao ◽  
Zhijiang Du ◽  
Miao Yang ◽  
Wei Dong
Keyword(s):  
Load Capacity ◽  
The Novel ◽  
Nsga Ii ◽  
Element Analysis ◽  
Symmetrical Structure ◽  
Amplification Ratio ◽  
Flexure Hinges ◽  
Frequency Calculation ◽  
The Matrix ◽  
Novel Design

A displacement amplifier based on the bridge-lever-type hinge mechanisms is developed and optimized in this paper. The proposed design not only maintains a compact and symmetrical structure, but also features a high amplification ratio. To reduce the displacement loss and enhance the load capacity of the amplifier, the hybrid flexure hinges are employed in the novel design. The analyzed models for the amplification ratio and resonance frequency calculation are established based on the matrix method and Lagrangian method respectively, which are verified by finite-element analysis (FEA) and displacement experiment. Based on the established model, an optimization via the NSGA-II algorithm is performed to estimate the performance of the hinge mechanism.

scholarly journals Computational Analysis of Mechanical Performance for Composite Polymer Biodegradable Stents

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6016
Author(s):  
Žiga Donik ◽  
Branko Nečemer ◽  
Matej Vesenjak ◽  
Srečko Glodež ◽  
Janez Kramberger
Keyword(s):  
Composite Structures ◽  
Mechanical Performance ◽  
Bare Metal Stents ◽  
Metal Stents ◽  
Elastic Recoil ◽  
Element Analysis ◽  
Biodegradable Stents ◽  
Vascular Scaffolds ◽  
Drug Eluting ◽  
Promising Solution

Bioresorbable stents (BRS) represent the latest generation of vascular scaffolds used for minimally invasive interventions. They aim to overcome the shortcomings of established bare-metal stents (BMS) and drug-eluting stents (DES). Recent advances in the field of bioprinting offer the possibility of combining biodegradable polymers to produce a composite BRS. Evaluation of the mechanical performance of the novel composite BRS is the focus of this study, based on the idea that they are a promising solution to improve the strength and flexibility performance of single material BRS. Finite element analysis of stent crimping and expansion was performed. Polylactic acid (PLA) and polycaprolactone (PCL) formed a composite stent divided into four layers, resulting in sixteen unique combinations. A comparison of the mechanical performance of the different composite configurations was performed. The resulting stresses, strains, elastic recoil, and foreshortening were evaluated and compared to existing experimental results. Similar behaviour was observed for material configurations that included at least one PLA layer. A pure PCL stent showed significant elastic recoil and less shortening compared to PLA and composite structures. The volumetric ratio of the materials was found to have a more significant effect on recoil and foreshortening than the arrangement of the material layers. Composite BRS offer the possibility of customising the mechanical behaviour of scaffolds. They also have the potential to support the fabrication of personalised or plaque-specific stents.

Design and Analysis of a Novel Structure Form of Electro-Mechanical Transmission

2013 ◽  
Vol 694-697 ◽  
pp. 497-502
Author(s):  
Jiang Tao Gai ◽  
Shou Dao Huang ◽  
Guang Ming Zhou ◽  
Yi Yuan
Keyword(s):  
Mechanical Transmission ◽  
The Novel ◽  
Structure Form ◽  
Tracked Vehicle ◽  
Power Coupling ◽  
Advantages And Disadvantages ◽  
Vehicle Propulsion ◽  
Novel Structure ◽  
Straight Line ◽  
Planetary Mechanism

In order to search after a new way of the propulsion system of tracked vehicle, a novel structure form of electro-mechanical transmission was developed in this paper, through analyzing the advantages and disadvantages of existing projects of electric drive system for tracked vehicle. It could increase the rate of power exertion obviously and synthesize the mechanical and electrical strongpoint. And based on the structure form, an electro-mechanical transmission was designed with double electromotor added planetary mechanism of steering power coupling and gearshift, considering engineering realization. And then straight-line driving and steering performances of the transmission were calculated which proved that the novel electro-mechanical transmission could meet the requirement of tracked vehicle propulsion well.

scholarly journals Design and Characterization of Microscale Auxetic and Anisotropic Structures Fabricated by Multiphoton Lithography

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 446
Author(s):  
Ioannis Spanos ◽  
Zacharias Vangelatos ◽  
Costas Grigoropoulos ◽  
Maria Farsari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Performance ◽  
Element Analysis ◽  
Mechanical Responses ◽  
Multiphoton Lithography ◽  
Anisotropic Structures ◽  
Scanning Electron

The need for control of the elastic properties of architected materials has been accentuated due to the advances in modelling and characterization. Among the plethora of unconventional mechanical responses, controlled anisotropy and auxeticity have been promulgated as a new avenue in bioengineering applications. This paper aims to delineate the mechanical performance of characteristic auxetic and anisotropic designs fabricated by multiphoton lithography. Through finite element analysis the distinct responses of representative topologies are conveyed. In addition, nanoindentation experiments observed in-situ through scanning electron microscopy enable the validation of the modeling and the observation of the anisotropic or auxetic phenomena. Our results herald how these categories of architected materials can be investigated at the microscale.

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