scholarly journals Finite Element Modeling and Experimental Validation of a z-Type Self-Expanding Endovascular Stent

2021 ◽  
Author(s):  
Joel Scott ◽  
Darrel Doman ◽  
Clifton Johnston
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Stent Migration ◽  
Radial Force ◽  
Aneurysm Rupture ◽  
Outer Diameter ◽  
Type I ◽  
Cross Sectional ◽  
Endovascular Stents

Stent migration due to haemodynamic drag remains the primary cause of type I endoleak, potentially leading to aneurysm rupture. The prevalence of migration and endoleak can be partially attributed to deficiencies in stent-graft radial spring design and a lack in understanding of the mechanical properties of endovascular stents. A converged finite element model of a custom radial extensometer was developed, fit, and validated using experimental results for bare stent wire (”uncovered”) with outer diameter of 12 mm stent. During stent constriction to 50 % of the original cross- sectional area, a comparison of experimental and modeled results produced an r2 value of 0.946, a standard error of 0.099 N, and a mean percent error of 1.69 %. This validated finite element model can be used to analyze the mechanisms responsible for radial force generation in 316L stainless steel self-expanding endovascular stents, as well as to evaluate new stent designs.

Modeling of Deformations in a Ring Shaped Workpiece Due to Chucking and Cutting Forces

Manufacturing ◽  
2002 ◽  
Author(s):  
John A. Malluck ◽  
Shreyes N. Melkote
Keyword(s):  
Finite Element ◽  
Theoretical Model ◽  
Finite Element Model ◽  
Cutting Forces ◽  
Element Model ◽  
Outer Diameter ◽  
Classical Elasticity ◽  
Elastic Deformations ◽  
The Finite Element Model ◽  
Classical Elasticity Theory

This paper presents a theoretical model for predicting the elastic deformations of ring-type workpieces due to in-plane chucking and cutting forces applied in turning processes. The model is derived from classical elasticity theory for bending of thin rings. Experimental results are presented to verify the strengths and limitations of this model. The results from a finite element model are also presented for comparison. For the ring diameters and radial chucking loads considered in this work, it is shown that the theoretical model is accurate to within 11% of the measured radial deformations for rings with inner-to-outer diameter ratio (Din/Dout) of 0.881. The finite element model is shown to yield slightly better results. The applicability of the theoretical model is illustrated by using it to predict the surface error produced in turning of a ring.

Behaviour of cold-formed steel built-up I-section columns composed of four U-profiles

2018 ◽  
Vol 22 (3) ◽  
pp. 613-625 ◽  
Author(s):  
M Anbarasu ◽  
M Venkatesan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Ultimate Strength ◽  
Element Model ◽  
Cross Sectional ◽  
Direct Strength Method ◽  
The North ◽  
Compression Members ◽  
Cross Sectional Dimension ◽  
Cold Formed Steel

This work reports numerical results concerning the cold-formed steel built-up I-section columns composed of four U-profiles under axial compression. A finite element model is developed by using the software program ABAQUS. The developed model includes geometric, material nonlinearities and geometric imperfections. The finite element model was verified against the experimental results reported in the cold-formed steel built-up open section columns. In the parametric study, the sections are analysed with several cross-sectional dimension ratios and lengths, in order to assess their influence on the buckling behaviour and ultimate strength of cold-formed steel built-up I-section columns. After presenting and discussing the numerical parametric results, the article shows that the current direct strength method in the North American Specification for cold-formed steel compression members design curve fails to predict adequately the ultimate strength of some of the columns analysed and addresses the modification proposed on current direct strength method curves, providing improved predictions of all the numerical ultimate strength available. The proposed method is also assessed by reliability analysis.

Finite element model of a novel short stemmed total hip arthroplasty implant developed from cross sectional CT scans

2013 ◽  
Vol 21 (5) ◽  
pp. 493-500 ◽  
Author(s):  
Matthias Lerch ◽  
Nelly Weigel ◽  
Henning Windhagen ◽  
Max Ettinger ◽  
Fritz Thorey ◽  
...  
Keyword(s):  
Finite Element ◽  
Total Hip Arthroplasty ◽  
Finite Element Model ◽  
Hip Arthroplasty ◽  
Element Model ◽  
Ct Scans ◽  
Cross Sectional ◽  
Total Hip

Modeling of a Rear-End Crash Pulse Generator

2012 ◽  
Vol 630 ◽  
pp. 360-365
Author(s):  
Hai Bin Chen ◽  
Ling Zhang ◽  
Li Ying Zhang ◽  
Xue Mei Cheng ◽  
Zheng Guo Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Pulse Generator ◽  
Element Model ◽  
Outer Diameter ◽  
Time Curve ◽  
International Regulation ◽  
Safety Research ◽  
The Impact ◽  
Deceleration Time

The rear-end crash pulse generator has been considered to be a key device for performing car impact safety research under laboratory conditions. According to the international regulation, ECE R44, the polyurethane (PU) tube was recommended to produce a standard rear-end pulse. However, little literatures on the impact dynamics of PU tube were known. In this study, a was established under ANSYS/LS-DYNA. With this finite element model, the following conditions to generate the standard rear-end impact pulses were determined: the initial impact velocity of sled was 30km/h, the resultant mass of sled was 680kg, number of PU-tubes was three, and outer diameter of olive knob was 46mm. Compared with the standard deceleration-time curve of actual rear-end crash, this finite element model of rear-end crash pulse generator was preliminarily validated.

A Truck Cab Abnormal Vibration Test and Analysis

2013 ◽  
Vol 416-417 ◽  
pp. 1803-1807
Author(s):  
Qiang Li ◽  
Yan Fang Liu ◽  
Xiang Yang Xu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Radial Force ◽  
Test Results ◽  
Element Simulation ◽  
Force Variation ◽  
Specific Speed ◽  
The Finite Element Model

This paper introduces a combination of testing and finite element simulation for the abnormal vibration of a truck cab in specific speed. Vibration characteristics of the truck is tested. The factors that caused the abnormal vibration of the truck is found. The finite element model is established and the modal analysis is performed, the correctness of the test results is verified, and a reliable finite element model for the follow-up solution is provided. The abnormal vibration was caused by the frequencies of radial force variation which almost equal to the truck natural frequency under the vehicle velocities of 50km/h. The approach described in this paper can be applied to similar vibration problem diagnosis.

Deformation Relaxation: A Finite Element Optimization Method for Tee

2003 ◽  
Author(s):  
Shijun Wang ◽  
Jinjuan Zhao
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Finite Element Model ◽  
Element Model ◽  
Optimization Method ◽  
New Method ◽  
Outer Diameter ◽  
Intensity Level ◽  
Analysis Models ◽  
Experiment Analysis

In this paper, an optimization method for a tee is proposed. A finite element model of a tee is built and its reliability is demonstrated by experiment. Analysis models with different fillet radii are analyzed. The results show that changing the fillet radius can not distinctly change the stress intensity level. Therefore, deformation relaxation, a new method for lowering stress intensity levels, is proposed. The method’s core is that the original shape of the tee is modified by deformation displacement. The computed results show that the decrease of the highest stress intensity is approximately in proportion to the modification. When the maximum modification is up to 10% of the outer diameter of main pipe, the highest stress intensity decreases by 52.2%.

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