Loading comparison of two structures in the moving tube of a non-invasive prosthesis

2021 ◽  
pp. 1-9
Author(s):  
Jie Zhang ◽  
Ping Ye ◽  
Lizheng Zhang ◽  
Hongliu Wu ◽  
Tianxi Chi ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Normal Growth ◽  
Limb Length Discrepancy ◽  
The Body ◽  
Lower Limbs ◽  
Lower Body ◽  
Element Analysis ◽  
Non Invasive ◽  
Testing Method ◽  
Finite Element Analysis Simulation

BACKGROUND: The treatment of adolescent patients with distal femoral cancer has always been a concern. The limb-salvage, regarded as a mainstream treatment, had been developed in recent years, but its application in children still remains challenging. This is because it can lead to potential limb-length discrepancy from the continued normal growth of the contralateral lower body. The extendable prosthesis could solve this problem. The principle is that it can artificially control the length of the prosthesis, making it consistent with the length of the side of the lower limbs. However, this prosthesis has some complications. The extendable prosthesis is classified into invasive and minimally invasive, which extends the prosthesis with each operation. OBJECTIVE: We designed a new non-invasive prosthesis that can be extended in the body. Based on the non-invasive and extendable characteristics, we need to verify the supporting performance of this prosthesis. METHODS: We carried out a mechanical testing method and finite element analysis simulation. CONCLUSION: The support performance and non-invasively extension of this prosthesis were verified.

scholarly journals Design and Analysis of Dual Mover Multi-Tooth Permanent Magnet Flux Switching Machine for Ropeless Elevator Applications

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 81
Author(s):  
Atif Zahid ◽  
Faisal Khan ◽  
Naseer Ahmad ◽  
Irfan Sami ◽  
Wasiq Ullah ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Iron Core ◽  
Analytical Prediction ◽  
Element Analysis ◽  
Design Structure ◽  
Finite Element Analysis Simulation ◽  
Analysis Package ◽  
Flux Switching Motor

A dual mover yokeless multi-tooth (DMYMT) permanent magnet flux switching motor (PM-FSM) design is presented in this article for ropeless elevator applications. The excitation sources, including a field winding and permanent magnet, are on the short mover in the proposed design structure, whereas the stator is a simple slotted iron core, thus reducing the vertical transportation system cost. The operational principle of the proposed DMYMT in PM-FSM is introduced. The proposed dual mover yokeless multi-tooth Permanent Magnet Flux Switching Motor is analyzed and compared for various performance parameters in a Finite Element Analysis package. The proposed machine has high thrust force and cost-effectiveness compared to conventional dual permanent magnet motor. Finally, this paper also develops an analytical model for the proposed structure, validated by comparing it with Finite Element Analysis simulation results. Results show good agreement between analytical prediction and Finite Element Analysis results.

scholarly journals Modeling the pelvic region for non-invasive pelvic intraoperative neuromonitoring

2016 ◽  
Vol 2 (1) ◽  
pp. 185-188 ◽  
Author(s):  
Tomasz Moszkowski ◽  
Thilo Krüger ◽  
Werner Kneist ◽  
Klaus-Peter Hoffmann
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Intraoperative Neuromonitoring ◽  
Tetrahedral Mesh ◽  
Mesorectal Excision ◽  
Element Analysis ◽  
Pelvic Region ◽  
Non Invasive ◽  
Muscle Tissues ◽  
Mesh Models

AbstractFinite element analysis (FEA) of electric current distribution in the pelvis minor may help to assess the usability of non-invasive surface stimulation for continuous pelvic intraoperative neuromonitoring. FEA requires generation of quality volumetric tetrahedral mesh geometry. This study proposes the generation of a suitable mesh based on MRI data. The resulting volumetric mesh models the autonomous nerve structures at risk during total mesorectal excision. The model also contains the bone, cartilage, fat, skin, muscle tissues of the pelvic region, and a set of electrodes for surface stimulation. The model is ready for finite element analysis of the discrete Maxwell’s equations.

scholarly journals Effects of Unweighting on Gait Kinematics During Walking on a Lower-Body Positive-Pressure Treadmill in Patients with Hip Osteoarthritis

2021 ◽  
Author(s):  
Yoshiaki Kataoka ◽  
Tomohiro Shimizu ◽  
Ryo Takeda ◽  
Shigeru Tadano ◽  
Yuki Saito ◽  
...  
Keyword(s):  
Rating Scale ◽  
Plantar Flexion ◽  
Weight Bearing ◽  
Hip Osteoarthritis ◽  
The Body ◽  
Lower Limbs ◽  
Positive Pressure ◽  
Control Group ◽  
Lower Body ◽  
Gait Kinematics

Abstract Background: Hip osteoarthritis (OA) is a musculoskeletal condition that makes walking difficult due to pain induced by weight-bearing activities. Treadmills that support the body weight (BW) reduce the load on the lower limbs, and those equipped with a lower-body positive-pressure (LBPP) device, developed as a new method for unweighting, significantly reduce pain in patients with knee OA. However, the effects of unweighting on gait kinematics remain unclear in patients with hip OA. Therefore, we investigated the effects of unweighting on kinematics in patients with hip OA during walking on a treadmill equipped with an LBPP device. Methods: A total of 15 women with hip OA and 15 age-matched female controls wore a three-dimensional (3-D) motion analysis system and walked at a self-selected speed on the LBPP treadmill. Data regarding self-reported hip pain using a numeric rating scale (NRS) in which the scores 0 and 10 represented no pain and the worst pain, respectively, under three different BW conditions (100%, 75%, and 50%) were collected. Moreover, 3-D peak joint angles during gait under each condition were calculated and compared. Results: In the hip OA group, the NRS pain scores at 50% and 75% BW conditions significantly decreased compared with that at 100% BW condition (50%, P=0.002; 75%, P=0.026), and the peak hip extension angle decreased compared with that in the healthy controls (P=0.044). In both groups, unweighting significantly decreased the peak hip (P<0.001) and knee (P<0.001) flexion angles and increased the peak ankle plantar flexion angle (P<0.001) during walking. Conclusions: Unweighting by the LBPP treadmill decreased pain in the hip OA group but did not drastically alter the gait kinematics compared with that in the control group. Therefore, regarding the use of the LBPP treadmill for patients with hip OA, clinicians should consider the benefits of pain reduction rather than the kinematic changes.

Rigid-Plastic Finite Element Simulation of Cold Forging and Sheet Metal Forming by Eulerian Meshing Method

2014 ◽  
Vol 970 ◽  
pp. 177-184 ◽  
Author(s):  
Wen Chiet Cheong ◽  
Heng Keong Kam ◽  
Chan Chin Wang ◽  
Ying Pio Lim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Large Deformation ◽  
Sheet Metal ◽  
Metal Forming ◽  
The Body ◽  
Cold Forging ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Linear Solution

A computational technique of rigid-plastic finite element method by using the Eulerian meshing method was developed to deal with large deformation problem in metal forming by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. During metal forming process, a workpiece normally undergoes large deformation and causes severe distortion of elements in finite element analysis. The distorted element may lead to instability in numerical calculation and divergence of non-linear solution in finite element analysis. With Eulerian elements, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. Four types of cold forging and sheet metal clinching were conducted to investigate the effectiveness of the presented method. The proposed method is found to be effective by comparing the results on dimension of the final product, material flow behaviour and punch load versus stroke obtained from simulation and experiment.

The Evaluation of Failure Pressure for Corrosion Defects Within Girth or Seam Weld in Transmission Pipelines

2004 ◽  
Author(s):  
Young-pyo Kim ◽  
Woo-sik Kim ◽  
Young-kwang Lee ◽  
Kyu-hwan Oh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Limit Load ◽  
The Body ◽  
Element Analysis ◽  
Burst Test ◽  
Corrosion Defect ◽  
Seam Weld ◽  
Failure Assessment ◽  
Corrosion Defects

The failure assessment for corroded pipeline has been considered with the burst test and the finite element analysis. The burst tests were conducted on 762mm diameter, 17.5mm wall thickness and API 5L X65 pipe that contained specially manufactured rectangular corrosion defect. The failure pressures for corroded pipeline have been measured by burst testing and classified with respect to corrosion sizes and corroded regions — the body, the girth weld and the seam weld of pipe. Finite element analysis was carried out to derive failure criteria of corrosion defect within the body, the girth weld and the seam weld of the pipe. A series of finite element analyses were performed to obtain a limit load solution for corrosion defects on the basis of burst test. As a result, the criteria for failure assessment of corrosion defect within the body, the girth weld and the seam weld of API 5L X65 gas pipeline were proposed.

Thermal compensation using the hybrid metrology approach compared to traditional scaling

2017 ◽  
Vol 232 (13) ◽  
pp. 2364-2374
Author(s):  
David Ross-Pinnock ◽  
Glen Mullineux
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Expansion ◽  
Temperature Measurement ◽  
Large Scale ◽  
Element Analysis ◽  
Linear Temperature ◽  
Temperature Distributions ◽  
Finite Element Analysis Simulation ◽  
Uniform Scaling

Control of temperature in large-scale manufacturing environments is not always practical or economical, introducing thermal effects including variation in ambient refractive index and thermal expansion. Thermal expansion is one of the largest contributors to measurement uncertainty; however, temperature distributions are not widely measured. Uncertainties can also be introduced in scaling to standard temperature. For more complex temperature distributions with non-linear temperature gradients, uniform scaling is unrealistic. Deformations have been measured photogrammetrically in two thermally challenging scenarios with localised heating. Extended temperature measurement has been tested with finite element analysis to assess a compensation methodology for coordinate measurement. This has been compared to commonly used uniform scaling and has outperformed this with a highly simplified finite element analysis simulation in scaling a number of coordinates at once. This work highlighted the need for focus on reproducible temperature measurement for dimensional measurement in non-standard environments.

Stretching and Chamfering Finite Element Analysis of Rotor Loose Compaction Based on DEFORM

2014 ◽  
Vol 543-547 ◽  
pp. 3-6
Author(s):  
Jie Min ◽  
Hai Sheng Wang ◽  
De Wei Guo ◽  
Wen Bin Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Relative Density ◽  
Element Analysis ◽  
Substantial Impact ◽  
Steel Billet ◽  
Fea Model ◽  
Simulated Environment ◽  
Finite Element Analysis Simulation

DEFORM is a software used for FEA (Finite Element Analysis) simulation. By using this software, I take a research on the procedure when a steel billet with defect of artificial loosening is drawn out in a simulated environment. Then I build a FEA model about the loosening and compaction of a large-sized rotor and stimulate the procedure in accordance with current craft card involving rotor forging. Finally, I get a result: the relative density of the loose area reaches up to 85% after the first drawing-out process (note: forging ratio 1.47). After simulating the procedure of chamfering on a billet which has been already drawn out, I found that chamfering had little substantial impact on the its loosening and compaction.

Finite Element Analysis of Buckling of Arteries With Aneurysms

2009 ◽  
Author(s):  
Avione Northcutt ◽  
Hai-Chao Han
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
The Body ◽  
Element Analysis ◽  
Arterial Tortuosity ◽  
Dangerous Condition ◽  
Cerebrovascular Symptoms

Tortuosity of arteries occurs when a normally straight artery starts to take on a twisted path. This is often referred to as tortuosity and kinking of arteries. This phenomenon occurs in arteries throughout the body including the aorta and cerebral [1, 2]. Arterial tortuosity is a potentially dangerous condition that can lead to cerebrovascular symptoms, ischemia, and stroke [3].

Investigation on the Bending Ratcheting Behavior of Pressurized Z2CND18.12N Stainless Steel Elbows

2013 ◽  
Vol 573 ◽  
pp. 69-75 ◽  
Author(s):  
Xiao Hui Chen ◽  
Duo Min Li ◽  
Jian Bei Zhu ◽  
Xu Chen
Keyword(s):  
Finite Element Analysis ◽  
Stainless Steel ◽  
Axial Direction ◽  
Element Analysis ◽  
Ratcheting Strain ◽  
Finite Element Analysis Simulation ◽  
Bending Load ◽  
Simulation And Experiment ◽  
Bending Loading ◽  
Hoop Direction

A series of ratcheting experiments and finite element analysis simulation under bending loading for Z2CND18.12N stainless steel elbows were carried out. Chaboche and modified Ohno-Wang model are applied to evaluate structural ratcheting response simulations. It is found that ratcheting strain initiates firstly in the hoop direction and increases in the axial direction with the increasing of loading. The Ratcheting strain rate grows with the increase of the reversed in-plane bending load or internal pressure for both specimens with different loadings. Comparison of simulation and experiment showed that modified Ohno-Wang model presented simulation more reasonably.

Finite Element Simulation for Forging Process Using Euler’s Fixed Meshing Method

2008 ◽  
Vol 575-578 ◽  
pp. 1139-1144 ◽  
Author(s):  
Chan Chin Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Large Deformation ◽  
The Body ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Forging Process ◽  
Deformation Problem ◽  
Element Method

A simulator based on rigid-plastic finite element method is developed for simulating the plastic flow of material in forging processes. In the forging process likes backward extrusion, a workpiece normally undergoes large deformation around the tool corners that causes severe distortion of elements in finite element analysis. Since the distorted elements may induce instability of numerical calculation and divergence of nonlinear solution in finite element analysis, a computational technique of using the Euler’s fixed meshing method is proposed to deal with large deformation problem by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. With this method, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. The proposed method is found to be effective in simulating complicated material flow inside die cavity which has many sharp edges, and also the extrusion of relatively slender parts like fins. In this paper, the formulation of rigid-plastic finite element method based on plasticity theory for slightly compressible material is introduced, and the advantages of the proposed method as compared to conventional one are discussed.

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