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.

An Application of Finite-Element Method To The Deformation Analysis of Coated Plain-Weave Fabrics

1982 ◽  
Vol 11 (4) ◽  
pp. 310-327
Author(s):  
H. Irokazu ◽  
M. Inami ◽  
Yoshio Nakahara
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Uniaxial Stress ◽  
Deformation Analysis ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Membrane Structures ◽  
Plain Weave ◽  
Weave Fabric ◽  
Element Method

Methods for analysing coated plain-weave fabric which has properties of nonlinear elasticity have not yet been satisfactorily developed. In this paper, a method which is promis ing for use in engineering applications like the strength analysis of membrane structures is presented. The finite element method using a rectangular element consisting of plain-weave fabric and coating material which is assumed to be an isotropic elastic plate of plane stress is applied to the method. Verification of the me thod is made by using uniaxial stress-strain responses. A square piece of coated plain-weave fabric with a square hole in it is analyzed as an example of application of the present method. Key Words: coated plain-weave fabrics; finite element method; nonlinearly elastic biaxial response; geometrically nonlinear prob lem ; incremental approach.

scholarly journals STRENGTH ANALYSIS OF VARIABLE RIGIDITY SLABS ON ELASTIC SUPPORT WITH VARIABLE SUBGRADE RATIO

2019 ◽  
pp. 201-208
Author(s):  
E. V. Barmekova
Keyword(s):  
Differential Equation ◽  
Finite Element Method ◽  
Finite Element ◽  
Elastic Support ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Variable Rigidity ◽  
Different Thickness ◽  
Element Method

The paper presents the strength analysis of variable rigidity slabs on elastic support with the variable subgrade ratio. The analysis is based on a solution of the differential equation of the slab flexure using the finite element method. The results are obtained for different slabs on the elastic support. The results are presented for the different thickness of the upper layer of the two-layer slab on the elastic support with the variable subgrade ratio.

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 Strength analysis of a boom sprayer with the use of CAD/CAE systems

Mechanik ◽  
2018 ◽  
Vol 91 (7) ◽  
pp. 549-551
Author(s):  
Waldemar Dudda
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Static Analysis ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Element Method

Presented are the results of strength analysis of the Pilmet boom sprayer. After creating the numerical model of the boom, a static analysis was carried out. Stresses and displacements were determined using the finite element method for different variants of the folding boom position.

Finite Element Analysis of Structure Strength on Engine Room of a Submerged Waterjet Propelled Ship

2020 ◽  
Author(s):  
Hanqi Wang ◽  
Jiangming Ding
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Modal Analysis ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Engine Room ◽  
Structure Strength ◽  
Stress And Deformation ◽  
Element Method

Abstract The submerged waterjet offers further benefits with respect to excellent stealth performance, low inflow energy loss, high propulsive efficiency at low and medium speeds, and excellent underwater acoustic performance. It also offers potential for space savings as a result of the high integration with the hull bottom. A parameterized stern line layout method for DTMB 5415 is proposed to design a new ship type fitted with submerged waterjet propeller. Based on the finite element method, the strength analysis and modal analysis of the new hull-form are carried out. The transom equipped with submerged waterjets is constructed by three main parameters which includes tunnel lengths, tunnel transverse positions and shaft angles. CFD calculation of hull flow field and resistance was carried out based on the designed new ship type to evaluate hydrodynamic load. Based on the finite element method, MSC.Patran/Nastran and Abaqus CAE was used to analysis the stress and deformation of the engine room under the static load, and the modal analysis of the engine room was carried out to calculate the vibration frequency and mode of the engine room. Numerical results show that the stress and deformation of the section are agree with the design and the section will not be broken. The different order total modal deformation and natural frequency are given, which lays a foundation for the research of vibration noise prediction and noise reduction technology of ship engine room.

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