scholarly journals Establishment of a Finite Element Model of Supination-external Rotation Ankle Joint Injury and Analysis of Mechanical Changes in the Posterior Malleolar Surface

2021 ◽  
Author(s):  
Xin Zhang ◽  
Pinliang Xie ◽  
Weirong Shao ◽  
Ming Xu ◽  
Xiaoping Xu ◽  
...  
Keyword(s):  
Finite Element ◽  
Ankle Joint ◽  
Maximum Stress ◽  
External Rotation ◽  
Element Model ◽  
Lateral Malleolus ◽  
Joint Surface ◽  
Maximum Pressure ◽  
Tibiofibular Ligament ◽  
Fibular Fracture

Abstract BackgroundBy establishing a three-dimensional finite element model of supination and external rotation ankle injury, the stress characteristics of the posterior ankle joint surface can be obtained, and complete analysis of the corresponding stress on the lateral ankle can be examined. MethodsThin-layer computed tomography (CT) images of normal ankle joints in the supination and external rotation non-weight-bearing states were selected, a three-dimensional data model of each ankle joint, including the ligament, was established, and whether different degrees of injury were coexistent with lateral ankle fracture was analysed by the finite element method. A load was applied to examine different ankle joint stress values and pressure distributions on the surface of the posterior ankle joint. ResultsWhen a load was applied, the maximum stress was located at the point of attachment of the anterior tibiofibular ligament to the tibia. When the anterior tibiofibular ligament was removed and the lateral malleolus was intact, the maximum stress (271.2 MPa) was located at the attachment point of the posterior tibiofibular ligament to the tibia, and the maximum pressure of the posterior ankle joint surface was 2.626 MPa. When a lateral malleolus fracture was present and the same load was applied, the maximum stress (82 MPa) was located on the fibular fracture surface, and the maximum pressure of the posterior ankle joint surface was 7.787 MPa. The posterior tibiofibular ligament was then removed completely from the lateral malleolus, and the maximum stress (132.7 MPa) was located at the point of attachment of the posterior tibiofibular ligament to the fibula, and the maximum pressure of the posterior ankle joint surface was 4.505 MPa. When a lateral malleolar fracture was present, the maximum stress (82.72 MPa) was located on the fibular fracture surface, and the maximum pressure of the posterior ankle joint surface was 8.022 MPa. ConclusionThis study shows that reconstruction of the lateral malleolus in supination-external rotation ankle injury significantly affects the stress distribution at the posterior malleolar joint surface. When reconstruction of the lateral malleolus is complete, the pressure distribution of the posterior malleolar joint surface can be significantly reduced. The results highlight the significance of reconstruction of posterior malleolar fractures and posterior tibiofibular ligament stability.

The Finite Element Analysis and Optimization for the Grinder Based on the Joint Surface

2013 ◽  
Vol 281 ◽  
pp. 165-169 ◽  
Author(s):  
Xiang Lei Zhang ◽  
Bin Yao ◽  
Wen Chang Zhao ◽  
Ou Yang Kun ◽  
Bo Shi Yao
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Element Model ◽  
Joint Surface ◽  
Weak Links ◽  
Response Analysis ◽  
Element Analysis ◽  
Static And Dynamic Analysis ◽  
Harmonic Response Analysis ◽  
Grinding Machine

Establish the finite element model for high precision grinding machine which takes joint surface into consideration and then carrys out the static and dynamic analysis of the grinder. After the static analysis, modal analysis and harmonic response analysis, the displacement deformation, stress, natural frequency and vibration mode could be found, which also helps find the weak links out. The improvement scheme which aims to increase the stiffness and precision of the whole machine has proposed to efficiently optimize the grinder. And the first natural frequency of the optimized grinder has increased by 68.19%.

Research of the Connecting Form about the Spherical Shell and the Nozzle

2011 ◽  
Vol 413 ◽  
pp. 520-523
Author(s):  
Cai Xia Luo
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Model ◽  
Spherical Shell ◽  
Maximum Stress ◽  
Peak Stress ◽  
Element Model ◽  
Small Opening ◽  
Large Opening ◽  
Reducing Stress

The Stress Distribution in the Connection of the Spherical Shell and the Opening Nozzle Is Very Complex. Sharp-Angled Transition and Round Transition Are Used Respectively in the Connection in the Light of the Spherical Shell with the Small Opening and the Large One. the Influence of the Two Connecting Forms on Stress Distribution Is Analyzed by Establishing Finite Element Model and Solving it. the Result Shows there Is Obvious Stress Concentration in the Connection. Round Transition Can Reduce the Maximum Stress in Comparison with Sharp-Angled Transition in both Cases of the Small Opening and the Large Opening, Mainly Reducing the Bending Stress and the Peak Stress, but Not the Membrane Stress. the Effect of Round Transition on Reducing Stress Was Not Significant. so Sharp-Angled Transition Should Be Adopted in the Connection when a Finite Element Model Is Built for Simplification in the Future.

Development of a Finite Element Model of the Inferior Glenohumeral Ligament of the Glenohumeral Joint

2003 ◽  
Author(s):  
William J. Newman ◽  
Richard E. Debski ◽  
Susan M. Moore ◽  
Jeffrey A. Weiss
Keyword(s):  
Finite Element ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Element Model ◽  
Fe Modeling ◽  
Glenohumeral Ligament ◽  
Subject Specific ◽  
Inferior Glenohumeral Ligament ◽  
Glenohumeral Capsule ◽  
Shoulder Stability

The shoulder is one of the most complex and often injured joints in the human body. The inferior glenohumeral ligament (IGHL), composed of the anterior band (AB), posterior band (PB) and the axillary pouch, has been shown to be an important contributor to anterior shoulder stability (Turkel, 1981). Injuries to the IGHL of the glenohumeral capsule are especially difficult to diagnose and treat effectively. The objective of this research was to develop a methodology for subject-specific finite element (FE) modeling of the ligamentous structures of the glenohumeral joint, specifically the IGHL, and to determine how changes in material properties affect predicted strains in the IGHL at 60° of external rotation. Using the techniques developed in this research, an improved understanding of the contribution of the IGHL to shoulder stability can be acquired.

A Finite Element Model of the Human Knee Joint for the Study of Tibio-Femoral Contact

2002 ◽  
Vol 124 (3) ◽  
pp. 273-280 ◽  
Author(s):  
Tammy L. Haut Donahue ◽  
M. L. Hull ◽  
Mark M. Rashid ◽  
Christopher R. Jacobs
Keyword(s):  
Finite Element ◽  
Articular Cartilage ◽  
Three Dimensional ◽  
Element Model ◽  
Maximum Pressure ◽  
Contact Behavior ◽  
Element Size ◽  
Solid Models ◽  
Flexion Extension ◽  
Three Dimensional Coordinate

As a step towards developing a finite element model of the knee that can be used to study how the variables associated with a meniscal replacement affect tibio-femoral contact, the goals of this study were 1) to develop a geometrically accurate three-dimensional solid model of the knee joint with special attention given to the menisci and articular cartilage, 2) to determine to what extent bony deformations affect contact behavior, and 3) to determine whether constraining rotations other than flexion/extension affects the contact behavior of the joint during compressive loading. The model included both the cortical and trabecular bone of the femur and tibia, articular cartilage of the femoral condyles and tibial plateau, both the medial and lateral menisci with their horn attachments, the transverse ligament, the anterior cruciate ligament, and the medial collateral ligament. The solid models for the menisci and articular cartilage were created from surface scans provided by a noncontacting, laser-based, three-dimensional coordinate digitizing system with an root mean squared error (RMSE) of less than 8 microns. Solid models of both the tibia and femur were created from CT images, except for the most proximal surface of the tibia and most distal surface of the femur which were created with the three-dimensional coordinate digitizing system. The constitutive relation of the menisci treated the tissue as transversely isotropic and linearly elastic. Under the application of an 800 N compressive load at 0 degrees of flexion, six contact variables in each compartment (i.e., medial and lateral) were computed including maximum pressure, mean pressure, contact area, total contact force, and coordinates of the center of pressure. Convergence of the finite element solution was studied using three mesh sizes ranging from an average element size of 5 mm by 5 mm to 1 mm by 1 mm. The solution was considered converged for an average element size of 2 mm by 2 mm. Using this mesh size, finite element solutions for rigid versus deformable bones indicated that none of the contact variables changed by more than 2% when the femur and tibia were treated as rigid. However, differences in contact variables as large as 19% occurred when rotations other than flexion/extension were constrained. The largest difference was in the maximum pressure. Among the principal conclusions of the study are that accurate finite element solutions of tibio-femoral contact behavior can be obtained by treating the bones as rigid. However, unrealistic constraints on rotations other than flexion/extension can result in relatively large errors in contact variables.

scholarly journals Comparative Analysis of Static Loading Performance of Rigid and Flexible Road Wheel based on Finite Element Method

2020 ◽  
Vol 70 (1) ◽  
pp. 41-46
Author(s):  
Yaoji Deng ◽  
Youqun Zhao ◽  
Mingmin Zhu ◽  
Zhen Xiao ◽  
Qiuwei Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Static Loading ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Element Model ◽  
Vertical Load ◽  
New Type ◽  
Stress And Deformation ◽  
Nonlinear Finite Element Model

To overcome the shortcomings of traditional rigid road wheel, such as poor damping effect and low load-bearing efficiency, a new type of flexible road wheel, having a unique suspension-bearing mode, was introduced. The three-dimensional nonlinear finite element model of rigid and flexible road wheel, considering the triple nonlinear characteristics of geometry, material and contact, is established for numerical investigation of static loading performance. The accuracy of the finite element model of the rigid and flexible road wheel is verified by static loading experiment. The static loading performance of the rigid and flexible road wheels is numerically analyzed. The influence of vertical load on maximum stress and deformation of the rigid and flexible wheels is also studied. The results show that the contact pressure uniformity of the flexible road wheel is better than that of the rigid road wheel under the static vertical load, but the maximum stress and deformation of the flexible road wheel are greater than that of the rigid road wheel. However, this problem can be solved by increasing the number of hinge sets and optimising the joints. The research results provide theoretical basis for replacing rigid road wheel with flexible road wheel, and also provide reference for structural optimisation of flexible road wheel.

The role of bending stress on the initiation of reverse transverse defects

2020 ◽  
Vol 235 (1) ◽  
pp. 61-72
Author(s):  
Soumyajit Mojumder ◽  
Hang Su ◽  
Cong Qiu ◽  
Peter Mutton ◽  
Aparna Singh ◽  
...  
Keyword(s):  
Finite Element ◽  
Iron Ore ◽  
Maximum Stress ◽  
Load Ratio ◽  
Element Model ◽  
Bending Stress ◽  
Vertical Load ◽  
Lower Head ◽  
Longitudinal Bending

This paper investigated the role of longitudinal reverse bending stress on the initiation of reverse transverse defects. The longitudinal reverse bending stress occurs due to the reverse bending of the rail between two-wheel passage leading to the generation of tensile bending stress at the railhead and the lower head areas. The longitudinal bending stress was investigated as part of a parametric study on the rail cant angle, rail stiffness, lateral-to-vertical load ratio, and rail profile. A finite element model was created by using ABAQUS to analyze the extent of reverse bending in rails with respect to the chosen set of parameters. Under different lateral-to-vertical load ratios of 0, 0.3, 0.5, and 0.7, the maximum stress at the rail lower gauge corner was found to vary between 14.57MPa and 15.47MPa under the reverse bending condition. Similarly, low values of tensile stress under the reverse bending scenario were observed with changes in the rail cant angle and axle spacing with respect to different coal and iron ore wagons. The results revealed that the magnitude of the bending stress under different conditions of reverse bending was not significant enough to initiate a crack at the lower gauge corner.

Mechanics Analysis and Optimization of the Reachstacker Spreader

2014 ◽  
Vol 1078 ◽  
pp. 266-270
Author(s):  
Yu Feng Shu ◽  
Yong Feng Zheng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Maximum Stress ◽  
Element Model ◽  
Static Strength ◽  
Operating Conditions ◽  
Mechanics Analysis ◽  
Calculation Results ◽  
Improvement Measures ◽  
The Finite Element Model

This paper establishes the finite element model of reachstacker spreader, makes static strength calculation under eight typical operating conditions with rated load, based on the calculation results, it points out the weaknesses of spreader and gives some corresponding improvement measures for the drawbacks. Further analysis shows that the maximum stress of improved spreader mechanism has reduced 10.1%, which demonstrates the effectiveness of improvements.

Identification of Bolt Connection Parameters for Vertical Grinding Machine in CAD/CAE Environment

2011 ◽  
Vol 697-698 ◽  
pp. 97-101
Author(s):  
Chao Hao Wang ◽  
Yong Liang Chen ◽  
Jin Ping Pang ◽  
Da Wei Zhang ◽  
G.X. Pan
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Element Model ◽  
Joint Surface ◽  
Element Analysis ◽  
Modal Test ◽  
Integrated Environment ◽  
Grinding Machine ◽  
Bolt Connection ◽  
The Mathematical Model

Dynamic analysis and modal test were conducted on a vertical grinding machine. The mathematical model of joint surface parameter identification between the bed and the column was established in CAD/CAE integrated environment. Based on the results of dynamic analysis and modal test, the parameters of joint surface were identified and the finite element model was accurately created. Then, the weak bodies of the original machine were improved. According to the finite element analysis of the improved machine, the performances of the new machine were better than the original machine.

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