scholarly journals On the Importance of Modeling Stent Procedure for Predicting Arterial Mechanics

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Shijia Zhao ◽  
Linxia Gu ◽  
Stacey R. Froemming
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Stress ◽  
Strain History ◽  
The Finite Element Method ◽  
Arterial Mechanics ◽  
History Of ◽  
Stent Diameter ◽  
The Impact ◽  
Stenting Procedure

The stent-artery interactions have been increasingly studied using the finite element method for better understanding of the biomechanical environment changes on the artery and its implications. However, the deployment of balloon-expandable stents was generally simplified without considering the balloon-stent interactions, the initial crimping process of the stent, its overexpansion routinely used in the clinical practice, or its recoil process. In this work, the stenting procedure was mimicked by incorporating all the above-mentioned simplifications. The impact of various simplifications on the stent-induced arterial stresses was systematically investigated. The plastic strain history of stent and its resulted geometrical variations, as well as arterial mechanics were quantified and compared. Results showed the model without considering the stent crimping process underestimating the minimum stent diameter by 17.2%, and overestimating the maximum radial recoil by 144%. It was also suggested that overexpansion resulted in a larger stent diameter, but a greater radial recoil ratio and larger intimal area with high stress were also obtained along with the increase in degree of overexpansion.

DESIGN AND ANALYSIS OF NEW STENT PATTERNS FOR ENHANCED PERFORMANCE

2020 ◽  
Vol 20 (06) ◽  
pp. 2050039
Author(s):  
NISANTHKUMAR PANNEERSELVAM ◽  
SREEKUMAR MUTHUSWAMY
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Blood Flow ◽  
Coronary Artery ◽  
Mechanical Behavior ◽  
Internal Diameter ◽  
Cell Design ◽  
The Finite Element Method ◽  
Stent Expansion ◽  
Stenting Procedure

Deploying a stent to restore blood flow in the coronary artery is very complicated, as its internal diameter is smaller than 3[Formula: see text]mm. It has already been proven that mechanical stresses induced on stent and artery during deployment make the placement of stent very difficult, besides the development of complications due to artery damage. Various stent designs have already been developed, especially in the metallic category. Still, there are possibilities for developing new stent designs and patterns to overcome the complexities of the existing models. Also, the technology of metallic stents can be carried forward towards the development of bioresorbable polymeric stents. In this work, three new stent cell designs (curvature, diamond, and oval) have been proposed to obtain better performance and life. The finite element method is utilized to explore the mechanical behavior of stent expansion and determine the biomechanical stresses imposed on the stent and artery during the stenting procedure. The results obtained have been compared with the available literature and found that the curvature cell design develops lower stresses and, hence, be suitable for better performance and life.

scholarly journals Selected aspects of numerical modelling in prediction of building vibrations due to traffic

2018 ◽  
Vol 196 ◽  
pp. 01055
Author(s):  
Sławomir Dudziak ◽  
Zofia Kozyra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modelling ◽  
The Finite Element Method ◽  
Frequency Range ◽  
Mass Estimation ◽  
Structure Response ◽  
Dynamic Analyses ◽  
Transportation Routes ◽  
The Impact

Dynamic analyses play an important role in the process of designing buildings in the vicinity of transportation routes. The Finite Element Method is the most popular modelling technique, because it allows to simulate the structure response in the higher frequency range properly. However, the results of such analyses depend on many factors and can differ a lot. This paper discusses the impact of the building mass estimation and neglecting or including damping in the analysis on the assessment of influence of vibrations due to traffic on people.

Stresses in a composite material with a single broken fibre

1967 ◽  
Vol 2 (3) ◽  
pp. 239-245 ◽  
Author(s):  
M J Iremonger ◽  
W G Wood
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Material ◽  
Composite Materials ◽  
High Stress ◽  
The Finite Element Method ◽  
Stress Concentrations ◽  
Lower Stress ◽  
Fibre Break ◽  
Matrix Yielding

An investigation has been made into the suitability of the finite-element method for studying the stresses in composite materials and the case of a single broken fibre in a matrix has been examined. It has been found that high stress concentrations occur in the region of the fibre break which increase with decreasing end gap and would cause matrix yielding or fracture at comparatively low overall stresses. When the end gap is not void but filled with matrix much lower stress concentrations occur which, below a certain value of end gap, actually decrease as the gap is made smaller.

An Ultrasonic Knife System for MEMS Packaging

2012 ◽  
Vol 190-191 ◽  
pp. 23-27
Author(s):  
Jin Sha ◽  
Zhi Yuan Yao ◽  
Yang Jiao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Temperature ◽  
High Frequency ◽  
Ultrasonic Transducer ◽  
The Finite Element Method ◽  
Structure Amplitude ◽  
High Frequency Vibration ◽  
Mems Packaging ◽  
The Impact

This paper proposes an ultrasonic knife system for MEMS packaging. The ultrasonic knife system is consisted of an ultrasonic transducer, a cutter and a gripper feeder. The ultrasonic transducer engenders high frequency vibration, which lead to the resonance of the structure. Amplitude transformer can magnify the amplitude. By the impact and collision of the cutter, the material can be cut through, and the high temperature created by high-frequency vibration can do the welding. The structure is designed and optimized by the finite element method, and a model machine is produced. According to the experimental results, the ultrasonic knife system has the virtues of high cutting force and better wedding feature, which are suitable for MEMS packaging.

Simulation of the Impact Behaviour of Diffusion-Bonded and Adhered Perforated Hollow Sphere Structures (PHSS)

2009 ◽  
Vol 294 ◽  
pp. 27-38 ◽  
Author(s):  
Fabian Ferrano ◽  
Marco Speich ◽  
Wolfgang Rimkus ◽  
Markus Merkel ◽  
Andreas Öchsner
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behaviour ◽  
Hollow Sphere ◽  
Large Deformations ◽  
The Finite Element Method ◽  
Impact Behaviour ◽  
New Type ◽  
The Impact

This paper investigates the mechanical properties of a new type of hollow sphere structure. For this new type, the sphere shell is perforated by several holes in order to open up the inner sphere volume and surface. The mechanical behaviour of perforated sphere structures under large deformations and strains in a primitive cubic arrangement is numerically evaluated by using the finite element method for different hole diameters and different joining techniques.

The Saturated - Unsaturated Seepage Analysis of Hualianshu Landslide on the Condition of Rainfall

2012 ◽  
Vol 594-597 ◽  
pp. 387-390
Author(s):  
Yu Hu ◽  
Qiang Feng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
The Finite Element Method ◽  
Seepage Field ◽  
Landslide Prediction ◽  
Reservoir Water ◽  
Seepage Analysis ◽  
Seepage Theory ◽  
The Impact ◽  
Unsaturated Seepage

With the saturated - unsaturated seepage theory, Hualianshu landslide is seepage numerical simulated by the finite element method .The changes of Hualianshu landslide seepage are subject to the impact of rainfall and reservoir water level's changes.The formation and variation of the slope seepage field under rainfall infiltration have been come to, providing a basis for analysis of slope stability and landslide prediction.

Improvements for a Hydraulic Excavator's Boom

2014 ◽  
Vol 490-491 ◽  
pp. 510-513
Author(s):  
Sheng Bin Wu ◽  
Xiao Bao Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
High Stress ◽  
The Finite Element Method ◽  
Element Method ◽  
Concentration Phenomenon

Focus on stress concentration and high stress area, four improvements were put forward through analyzed a hydraulic excavator's boom with the finite element method under the bucket digging condition. Compared the stress distribution graph, the results show that these schemes can improve the stress concentration phenomenon and the high stress distribution areas. The practices demonstrated the effectiveness to reduce the invalidation rate of hydraulic excavator's boom.

Mathematical Simulation of Rigid Pile Composite Foundation with Lateral Unloading

2013 ◽  
Vol 368-370 ◽  
pp. 756-759
Author(s):  
Jing Ma ◽  
Wen Sheng Chen ◽  
Xue Feng Hu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mathematical Simulation ◽  
Horizontal Displacement ◽  
Composite Foundation ◽  
The Finite Element Method ◽  
Rigid Pile ◽  
Rigid Pile Composite Foundation ◽  
The Impact ◽  
Element Method

Based on the Finite Element Method ,a model has been built to study the impact of rigid pile composite foundation with lateral unloading,then obtained a conclusion about the horizontal displacement during excavating.

scholarly journals Optimization Procedure of Roller Elements Geometry with Regard to Durability of Spherical Roller Bearings

2020 ◽  
Vol 22 (2) ◽  
pp. 68-72
Author(s):  
Jan Steininger ◽  
Stefan Medvecky ◽  
Robert Kohar ◽  
Tomas Capak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Roller Bearing ◽  
Optimization Procedure ◽  
Parametric Models ◽  
The Finite Element Method ◽  
Roller Bearings ◽  
Contact Points ◽  
The Impact ◽  
Element Method

The article deals with an optimization procedure of roller elements geometry with regard to durability of spherical roller bearings. The aim of the article is to examine the impact of change of the roller elements inner geometry on durability and reliability of spherical roller bearings; the contact strain along a spherical roller by means of the Finite Element Method at contact points of components of a spherical roller bearing by means of designed 3D parametric models. The most appropriate shape of roller elements inner geometry of a bearing from the standpoint of calculated durability was determined based on results of the contact analyses.

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