scholarly journals Finite element analysis of the tibial component alignment in frontal and sagittal plane in total knee arthroplasty

2021 ◽  
Vol 68 (3) ◽  
pp. 374-378
Author(s):  
Roman Popescu ◽  
◽  
Stefan Cristea ◽  
Adrian Marius Pascu ◽  
Valentin Oleksik ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Tibial Component ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Von Mises Stress ◽  
The Finite Element Method ◽  
Tibial Resection ◽  
Von Mises ◽  
Element Method

Background. This study aims to analyze the tibial component using the finite element method by cutting the tibial in frontal and sagittal planes at an angle between 1.5° (valgus and anterior tilt) and -1.5° (varus and posterior tilt). Methods. This experimental study used the finite element method as an useful tool for simulating the positioning of the tibial component in order to create a personal pre-operative planning. For the finite element method analysis, a geometrical model of a tibia from a cadaver was three – dimensionally scanned and the tibial component, polyethylene and cement, were three-dimensionally shaped in Computer-Aided Design program using material data such as Young modulus (gigapascal – GPa) and the Poisson coefficient. The analysis determined the equivalent von Mises stress, the maximum displacement of the components and the equivalent von Mises deformation. The results showed that equivalent tension and deformation have higher values in the tibia and the polyethylene, which deform faster than cement and the tibial component. In our study, we chose to simulate the tibial resection at a cutting angle ± 1.5° from neutral positioning (which is represented in frontal plane by the perpendicular on the mechanical axis and in sagittal plane by the posterior slope of 7 degree) in frontal and sagittal plane in order to find the minimum threshold from which the tibial component malalignment may begin to determine unfavorable effects. Results. Our results have shown detrimental effects begin to appear for the polyethene component at -1.5° in frontal plane, and the rest of the components at 1.5° in sagittal plane. Conclusion. This finding leads us to propose preoperative planning based on personal calculus of predefined angles, which may show the surgeon the optimal implantation position of the tibial component.

scholarly journals The Mechanical Behavior of Bone Cement in THR in the Presence of Cavities

2014 ◽  
Vol 4 (3) ◽  
pp. 625-630
Author(s):  
A. Benouis ◽  
B. Serier ◽  
B. Bachir Bouiadjra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Bone Cement ◽  
Von Mises Stress ◽  
Lateral Part ◽  
The Finite Element Method ◽  
Breaking Strain ◽  
Von Mises ◽  
Element Method

In this work we analyze three-dimensionally using the finite element method, the level and the Von Mises stress equivalent distribution induced around a cavity and between two cavities located in the proximal and distal bone cement polymethylmethacrylate (PMMA). The effects of the position around two main axes (vertical and horizontal) of the cavity with respect to these axes, of the cavity - cavity interdistance and of the type of loading (static) on the mechanical behavior of cement orthopedic are highlighted. We show that the breaking strain of the cement is largely taken when the cement in its proximal-lateral part contains cavities very close adjacent to each other. This work highlights not only the effect of the density of cavities, in our case simulated by cavity-cavity interdistance, but also the nature of the activity of the patient (patient standing corresponding to static efforts) on the mechanical behavior of cement.

scholarly journals A study of stress, displacements and strain in a stress concentrator using analytical calculus and Finite Element Method

2019 ◽  
Vol 1 (1) ◽  
pp. 13-20
Author(s):  
Brizeida Nohemí Ojeda
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentrator ◽  
The Finite Element Method ◽  
Von Mises ◽  
Element Method

A study of stresses, displacements, and strain, based on a classic solid mechanic’s model, specifically a plate with hole, around which a stresses concentration, is presented. For this purpose, the stresses analysis was carried out in a hole concentrator subjected to traction. The model's material was ASTM A36. The stresses were analytically calculated, through von Mises' theory. In addition, the analysis of the stresses using the finite element method (FEM) was carried out. Subsequently, displacements and unitary deformation were determined in the part. The results obtained report an error of 8.7% between the stresses of von Mises through analytical calculus and using the FEM.

scholarly journals THE EFFECTS OF INTERBRACKET DISTANCE AND GABLE BENDS ON THE FORCE AND MOMENTS IN A SEGMENTED ARCH APPROACH: A NUMERICAL-EXPERIMENTAL STUDY

2018 ◽  
Vol 48 (1) ◽  
pp. 63-67
Author(s):  
M. A. FERREIRA ◽  
F. R.M. RODRIGUES ◽  
P. C. BORGES ◽  
M. A. LUERSEN
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Finite Element ◽  
Statistical Difference ◽  
Von Mises Stress ◽  
The Finite Element Method ◽  
Force System ◽  
Space Closure ◽  
Von Mises ◽  
Deactivation Process

The present paper verified the effect of the interbracket distance on the force system developed by orthodontic retraction springs with two delta geometries measured during space closure when spaces between teeth are present. By using a platform transducer, five different interbracket distances were tested. Also the finite element method was applied to know the von Mises stress during spring activation/deactivation process. It was concluded that the interbracket distance and spring geometry variables have not caused significant influence on the force system resulting from activations, but activation has produced a statistical difference.

scholarly journals Desain dan Analisis Tegangan Alat Pengangkat Roket Kapasitas 10 Ton Menggunakan Metode Elemen Hingga

2019 ◽  
Vol 2 (01) ◽  
pp. 23-26
Author(s):  
Lasinta Ari Nendra Wibawa
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Von Mises Stress ◽  
The Finite Element Method ◽  
Safety Factors ◽  
Element Analysis ◽  
Simulation Results ◽  
Von Mises ◽  
Aluminum Alloy 7075

This study examines the design and stress analysis of a 10 ton capacity rocket lifting device using the finite element method. The material used is Aluminum alloy 7075. Finite element analysis is done numerically by using Autodesk Inventor Professional 2017. software The simulation results show that the structure of the rocket lift has Von Mises stress, deformation, mass, and safety factors of 46.34 MPa, 0.7947 mm, 186.75 kg, and 3.13.

ASSESSMENT OF THE BIOMECHANICAL COMPATIBILITY OF AN INTERSPINOUS IMPLANT FOR "DYNAMIC STABILIZATION" THROUGH THE FINITE ELEMENT METHOD

2005 ◽  
Vol 05 (02) ◽  
pp. 375-382 ◽  
Author(s):  
R. CONTRO ◽  
P. VENA ◽  
D. GASTALDI ◽  
G. FRANZOSO
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sagittal Plane ◽  
Compressive Force ◽  
Dynamic Stabilization ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Biomechanical Compatibility ◽  
Healthy State ◽  
Element Method

The paper addresses the biomechanical compatibility of an interspinous implant used for "dynamic stabilization" of a diseased intervertebral disc. A comparison between the behaviour of a titanium alloy ( Ti 6 Al 4 V ) implant and that of a superelastic alloy ( Ni - Ti ) implant has been carried out. The assessment of the biomechanical compatibility was achieved by means of the finite element method, in which suitably implemented constitutive laws for the materials have been used. The L4–L5 lumbar system in healthy state has been assumed as target for a biomechanically compatible implant. The L4–L5 system with the interspinous implant subjected to compressive force and bending moments has been simulated. A strength analysis for the bearing bone tissue in the posterior processes was also carried out. The results have shown that both implants were able to decrease the force on the apophyseal joints; however, the titanium-based implant exhibited a low biomechanical compatibility under extension-flexion in the sagittal plane; whereas the Ni - Ti exhibited a higher compatibility.

ASSESSMENT OF CORONARY STENT DEPLOYMENT IN TAPERED ARTERIES: IMPACT OF ARTERIAL TAPERING

2016 ◽  
Vol 16 (08) ◽  
pp. 1640015 ◽  
Author(s):  
XIANG SHEN ◽  
YONG-QUAN DENG ◽  
ZHONG-MIN XIE ◽  
SONG JI
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Clinical Success ◽  
The Finite Element Method ◽  
Stent Deployment ◽  
Biomechanical Behavior ◽  
Stent Restenosis ◽  
Comparison Results ◽  
Von Mises ◽  
Element Method

Coronary stents are used to prop open blocked arteries in order to restore normal blood flow. A major setback in this technology is in-stent restenosis (ISR), which gravely limits the clinical success of stents, especially in tapered vessels. The present study used the finite element method to study the effects of arterial tapering on the biomechanical behavior of both stents and vessels during stent deployment inside tapered arteries. The effect of arterial tapering was demonstrated by a combination of corresponding tapered arteries with various tapering angles, including a straight artery case for comparison. Results indicated that an increase of vessel tapering led to an increase in stent radial recoil, stent tapering following expansion, and von Mises stresses on vessels. However, an increase of vessel tapering also led to a decrease in stent foreshortening. The analysis provides suggestions for clinical application in tapered vessels. The finite element method evaluated mechanical stent behavior in tapered vessels, and can help designers to optimize the design of stents for tapered vessels.

Dynamic Analysis of a Novel Structure of Dry Coal Separator

2011 ◽  
Vol 402 ◽  
pp. 572-575
Author(s):  
Jun Li ◽  
Zhong Xian Wang ◽  
Feng Li ◽  
Chu Sheng Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequency ◽  
Working Condition ◽  
Von Mises Stress ◽  
Natural Mode ◽  
The Finite Element Method ◽  
Novel Structure ◽  
Working Frequency ◽  
Von Mises

This paper presents a novel structure of the dry coal separator with vibration fluidized bed and analyzed the dynamic characteristics of the vibration parts. The natural frequency, natural mode of vibration and dynamic response are calculated based on the finite element method. The results show that the natural frequency is far from working frequency, so that the structure can avoid resonance frequency effectively. The maximum von Mises stress is 0.01MPa which are allowed in the working condition.

scholarly journals Comparative Analysis of Healthy and Cam-Type Femoroacetabular Impingement (FAI) Human Hip Joints Using the Finite Element Method

2021 ◽  
Vol 11 (23) ◽  
pp. 11101
Author(s):  
Rubén Lostado Lorza ◽  
Fátima Somovilla Gomez ◽  
Marina Corral Bobadilla ◽  
Saúl Íñiguez Macedo ◽  
Asier Rodríguez San Miguel ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Femoroacetabular Impingement ◽  
Hip Joint ◽  
3D Models ◽  
Von Mises Stress ◽  
The Finite Element Method ◽  
Hip Joints ◽  
Element Analysis ◽  
Element Method

In this study, a human hip joint with Cam-type Femoroacetabular Impingement (FAI) is studied by the Finite Element Method (FEM). This pathology consists of a malformation that causes a lack of sphericity of the head of the femur. In turn, this causes wear and tear of the cartilage, a cause of early osteoarthritis of the hip. The objective is to use the FEM to analyze and compare the increase in the von Mises stress and displacement of the cartilage in healthy and damaged (with Cam-type) human hip joints that this syndrome affects. The 3D models were reconstructed from two medical CT scans of a healthy and a damaged hip joint that were obtained, five years apart, for a male of 80 kg in weight. The 3D models were reconstructed using 3D Slicer software. The cortical and trabecular bone, as well as the cartilage, were segmented. The defects were corrected by MesMixer software that generated STL files. Both models were imported into the Marc Mentat® software for the Finite Element Analysis (FEA). It was noted that the thickness of the cartilage decreased enormously during the five years, which suggests imminent mechanical contact between the head of the femur and the acetabulum of the pelvis. The FEA results showed an excessive increase in the stress and displacement of the cartilage. This will certainly result in a condition of osteoarthritis for the patient in the future years.

scholarly journals Numerical analysis on stress and displacement of tapered cantilever castellated steel beam with circular openings

2018 ◽  
Vol 195 ◽  
pp. 02007
Author(s):  
Taufiq Ilham Maulana ◽  
Hakas Prayuda ◽  
Bagus Soebandono ◽  
Martyana Dwi Cahyati ◽  
Eva Hanifatu Zahra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Yield Strength ◽  
Von Mises Stress ◽  
Steel Beams ◽  
Steel Beam ◽  
The Finite Element Method ◽  
Optimum Height ◽  
Von Mises

Castellated steel beams are made from normal steel beams cut into half with certain pattern and re-jointed to increase its height. This action results in many shapes of openings in its web, one of them being circular. Circular openings of castellated beams can also be implemented with single fix supported structures, but if uniform shape is used, it will reduce its effectiveness. In this paper, adoption of tapered shape on castellated beams with circular openings as cantilever structures will be discussed. This study uses 150x75x5x7 and 200x100x5.5x8 IWF sections with variations of opening diameters, opening spaces, and span lengths. The steel has a yield strength of 400 MPa and the analysis runs with solid element 10-node tetrahedron using the finite element method, by observing Von Mises stress and displacement. Free-licenced software such as LISAFEA 8.0 and FreeCAD are utilized for analysing and drawing solid elements. The result shows that the optimum height of IWF section for 150x75x5x7 is 230 mm and for 200x100x5.5x8 is 318 mm between span lengths of 2 m to 3.5 m. It can be concluded that each of the span lengths has various optimum diameters and opening spaces to acquire the smallest stress and displacement.

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