scholarly journals The Performance of a Spherical-tip Catheter for Stent Post-dilation: Finite Element Analysis and Experiments

2021 ◽  
Vol 12 ◽  
Author(s):  
Lin Qi ◽  
Wenbo Zhu ◽  
Wei Qian ◽  
Lisheng Xu ◽  
Ying He ◽  
...  

At present, percutaneous coronary intervention (PCI) is the most effective treatment of coronary artery stenosis. However, in case post-dilation of the stent is needed, the tip of the commonly used post-dilation balloon catheter cannot always pass through the stent smoothly, especially when it is situated in the curved part of the vessel. To improve the performance of traditional post-dilation balloon catheter, a preliminary design of a novel catheter with a spherical-tip is proposed. Since the performance of this spherical-tip catheter is still unclear, in this study, finite element analysis (FEA) and experimental validation of blood vessel with different curvature radii were performed to test and evaluate the performance of the spherical-tip catheter design. The comparative results between the two types of catheters demonstrate that in the simulated post-dilation process, the spherical-tip catheter is easier to pass through the stent placed in the curved vessel without the deformation of the stent strut, and can theoretically reduce the operation time and improve the safety of the operation. Furthermore, the strong consistency between simulation and experiment indicates that the finite element (FE) model can be a helpful tool for future optimization and evaluation of novel catheters, so as to save time and budget in product development and reduce/replace animal studies.

Author(s):  
Constantine M. Tarawneh ◽  
Arturo A. Fuentes ◽  
Javier A. Kypuros ◽  
Lariza A. Navarro ◽  
Andrei G. Vaipan ◽  
...  

In the railroad industry, distressed bearings in service are primarily identified using wayside hot-box detectors (HBDs). Current technology has expanded the role of these detectors to monitor bearings that appear to “warm trend” relative to the average temperatures of the remainder of bearings on the train. Several bearings set-out for trending and classified as nonverified, meaning no discernible damage, revealed that a common feature was discoloration of rollers within a cone (inner race) assembly. Subsequent laboratory experiments were performed to determine a minimum temperature and environment necessary to reproduce these discolorations and concluded that the discoloration is most likely due to roller temperatures greater than 232 °C (450 °F) for periods of at least 4 h. The latter finding sparked several discussions and speculations in the railroad industry as to whether it is possible to have rollers reaching such elevated temperatures without heating the bearing cup (outer race) to a temperature significant enough to trigger the HBDs. With this motivation, and based on previous experimental and analytical work, a thermal finite element analysis (FEA) of a railroad bearing pressed onto an axle was conducted using ALGOR 20.3™. The finite element (FE) model was used to simulate different heating scenarios with the purpose of obtaining the temperatures of internal components of the bearing assembly, as well as the heat generation rates and the bearing cup surface temperature. The results showed that, even though some rollers can reach unsafe operating temperatures, the bearing cup surface temperature does not exhibit levels that would trigger HBD alarms.


Author(s):  
R. N. Margasahayam ◽  
H. S. Faust

Abstract A finite-element stress analysis of a one-piece, integrated, all-composite shaft and coupling is presented. In addition to a brief discussion of design-driving parameters, some limitations of the analytical techniques used for design development are described. The 3D finite-element method (FEM) was then used to evaluate critical stresses and strains experienced by the shaft coupling. A comparison of the results from the finite-element analysis and those from static bending, axial, and torsional tests conducted on these prototype shafts yielded excellent correlation. Some important considerations in the development of the FE model and the correlation of results with tests, especially in the design of composite materials, are addressed.


Author(s):  
Mikkel L. Larsen ◽  
Vikas Arora ◽  
Marie Lützen ◽  
Ronnie R. Pedersen ◽  
Eric Putnam

Abstract Several methods for modelling and finite element analysis of tubular welded joints are described in various design codes. These codes provide specific recommendations for modelling of the welded joints, using simple weld geometries. In this paper, experimental hot-spot strain range results from a full-scale automatically welded K-node test are compared to corresponding finite element models. As part of investigating the automatically welded K-joint, 3D scans of the weld surfaces have been made. These scans are included in the FE models to determine the accuracy of the FE models. The results are compared to an FE model with a simple weld geometry based on common offshore design codes and a model without any modelled weld. The results show that the FE model with 3D scanned welds is more accurate than the two simple FE models. As the weld toe location of the 3D scanned weld is difficult to locate precisely in the FE model and as misplacement of strain gauges are possible, stochastic finite element modelling is performed to analyse the resulting probabilistic hot-spot stresses. The results show large standard deviations, showing the necessity to evaluate the hot-spot stress method when using 3D scanned welds.


Author(s):  
Phong Phan ◽  
Anh Vo ◽  
Amirhamed Bakhtiarydavijani ◽  
Reuben Burch ◽  
Brian K. Smith ◽  
...  

Abstract Computational approaches, especially Finite Element Analysis (FEA), have been rapidly growing in both academia and industry during the last few decades. FEA serves as a powerful and efficient approach for simulating real-life experiments, including industrial product development, machine design, and biomedical research, particularly in biomechanics and biomaterials. Accordingly, FEA has been a "go-to" high biofidelic software tool to simulate and quantify the biomechanics of the foot-ankle complex, as well as to predict the risk of foot and ankle injuries, which are one of the most common musculoskeletal injuries among physically active individuals. This paper provides a review of the in silico FEA of the foot-ankle complex. First, a brief history of computational modeling methods and Finite Element (FE) simulations for foot-ankle models is introduced. Second, a general approach to build a FE foot and ankle model is presented, including a detailed procedure to accurately construct, calibrate, verify, and validate a FE model in its appropriate simulation environment. Third, current applications, as well as future improvements of the foot and ankle FE models, especially in the biomedical field, are discussed. Lastly, a conclusion is made on the efficiency and development of FEA as a computational approach in investigating the biomechanics of the foot-ankle complex. Overall, this review integrates insightful information for biomedical engineers, medical professionals, and researchers to conduct more accurate research on the foot-ankle FE models in the future.


2012 ◽  
Vol 215-216 ◽  
pp. 847-850
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Hong Jie Wang

In the condition of alternating impact ,the nut-supports subassembly is analyzed according to uncertainty of design parameters. Firstly, a three-dimensional (3-D) finite element (FE) model of the nut-supports subassembly is built and is meshed,and the constraints and loads are imposed.Secondly,the model of nut-supports was assembled using the software ANSYS to understand the stress distribution and various parts of the deformation of the nut-supports and its weak links in the harmonic forces.Finally,socket head cap screw has not enough pre-load in the condition of alternating impact and will be simplified.It is analyzed and checked whether it is cut or not; which provides the reference data for design and optimization of the wave maker.


Author(s):  
Sung Jin Yoon ◽  
Tae Jin Shin ◽  
Jae Sang Lee ◽  
Sang Moo Hwang

This paper describes in detail the deformation behavior of the rolls and strip predicted from the three-dimensional finite element analysis of skin-pass rolling. The predictions are made on the basis of the coupled analysis of elastic deformation of the rolls and elastic–plastic deformation of the strip. Predictions from the proposed finite element (FE) model are compared with experimental data from laboratory-scale cold rolling mills. Then, proposed are models for the prediction of the roll force profile and for the prediction of the residual stress profile. The prediction accuracy of the models is examined through comparison with the predictions from the FE model.


Author(s):  
Zahra Shahbazi ◽  
Devon Keane ◽  
Domenick Avanzi ◽  
Lance S. Evans

Finite element analysis (FEA) has been one of the successful tools in studying mechanical behavior of biological materials. There are many instances where creating FE models requires extensive time and effort. Such instances include finite element analysis of tree branches with complex geometries and varying mechanical properties. Once a FE model of a tree branch is created, the model is not applicable to another branch, and all the modeling steps must be repeated for each new branch with a different geometry and, in some cases, material. In this paper, we describe a new and novel program “Immediate-TREE” and its associated guided user interface (GUI). This program provides researchers a fast and efficient tool to create finite element analysis of a large variety of tree branches. Immediate-TREE automates the process of creating finite element models with the use of computer-generated Python files. Immediate-TREE uses tree branch data (geometry, mechanical, and material properties) and generates Python files. Files were then run in finite element analysis software (abaqus) to complete the analysis. Immediate-TREE is approximately 240 times faster than creating the same model directly in the FEA software (abaqus). This new process can be used with a large variety of biological applications including analyses of bones, teeth, as well as known biological materials.


2019 ◽  
Vol 801 ◽  
pp. 65-70
Author(s):  
Jian Hong Gao ◽  
Xiao Xiang Yang

RVE combined with finite element analysis (FEA) is a very popular method to predict the mechanical property of the composite reinforced by short fibers. In the conventional method, generally the “tie” approach is used. By this method, the FE model with high fiber aspect ratio can not be achieved and the non-convergence of the numerical calculation may appear because of the complex mesh. The embedded element techinique is considered to be a replaceable method . Using this method, the mechanical behavior of composite with high fiber aspect ratio would be simulated. Therefore, in this study, the 3D solid element was employed for the FE model with multi cylinder particles. The comparisions of the Mise stress and the displacement between the embedded and conventional method indicate that compared with the stress transfer, the simulated result of composite stiffness is more accurate. In addition, the effects of model size, fiber orientated angle, fiber volume fraction and fiber aspect ratio were investigated. The numerical results were compared with the Mori-Tanaka model and the good agreements verify the applicability of the embedded element technique we studied in this paper.


2013 ◽  
Vol 330 ◽  
pp. 703-707 ◽  
Author(s):  
Tukaram S. Sarkate

Springs is defined as an elastic body that can reserve high level of potential energy, have various important role in industries. Helical spring is the most common element that has been used in car suspension system. Spring steel is low carbon alloy, medium carbon steel or high carbon steel with very high yield stress related to light vehicle suspension system. In this research paper AISI 9255, (containing 1.5%-1.8% silicon, 0.7%-1.0%manganese and 0.52%-.6% carbon) under the effect of a uniform loading has been studied. .The FE model of the helical spring has been generated in Pro-E Wildfire 5.0 software and imported in ANSYS-10 for finite element analysis, which are most popular CAE tools. Also finite element analysis has been compared with analytical solution for different loads under the same conditions to conclude.


Author(s):  
Bin Cai ◽  
Bo Li ◽  
Feng Fu

Abstract Fire tests and subsequent bending tests of four reinforced concrete (RC) beams were performed. Based on these tests, the post-fire performance of RC beams was further studied using finite-element simulation through reasonable selection of suitable thermal and thermodynamic parameters of steel and concrete materials. A thermodynamic model of RC beams with three sides under fire was built using finite-element analysis (FEA) software ABAQUS. The FEA model was validated with the results of fire tests. Different factors were taken into account for further parametric studies in fire using the propsed FE model. The results show that the main factors affecting the fire resistance of the beams are the thickness of the concrete cover, reinforcement ratio of longitudinal steel, the fire exposure time and the fire exposure sides. Based on the strength reduction formula at high temperature of steel and concrete and four test results, an improved section method was proposed to develop a calculation formula to calculate the flexural capacity of RC beams after fire. The theoretical calculation method proposed in this paper shows good agreement with FEA results, which can be used to calculate the flexural capacity of RC beams after fire.


Sign in / Sign up

Export Citation Format

Share Document