A three-dimensional finite element model from computed tomography data: A semi-automated method

2001 ◽  
Vol 215 (2) ◽  
pp. 203-212 ◽  
Author(s):  
P M Cattaneo ◽  
M Dalstra ◽  
L H Frich
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Three Dimensional ◽  
Patient Specific ◽  
Fe Model ◽  
Element Analysis ◽  
Automated Method ◽  
Bone Properties ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element analysis is one of the best ways to assess stress and strain distributions in complex bone structures. However, accuracy in the results may be achieved only when accurate input information is given. A semi-automated method to generate a finite element (FE) model using data retrieved from computed tomography (CT) was developed. Due to its complex and irregular shape, the glenoid part of a left embalmed scapula bone was chosen as working material. CT data were retrieved using a standard clinical CT scanner (Siemens Somatom Plus 2, Siemens AG, Germany). This was done to produce a method that could later be utilized to generate a patient-specific FE model. Different methods of converting Hounsfield unit (HU) values to apparent densities and subsequently to Young's moduli were tested. All the models obtained were loaded using three-dimensional loading conditions taken from literature, corresponding to an arm abduction of 90°. Additional models with different amounts of elements were generated to verify convergence. Direct comparison between the models showed that the best method to convert HU values directly to apparent densities was to use different equations for cancellous and cortical bone. In this study, a reliable method of determining both geometrical data and bone properties from patient CT scans for the semi-automated generation of an FE model is presented.

scholarly journals Evaluation of the Effects of the Chincup Appliance on the Craniofacial Structures by the Finite Element Analysis

2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Fe Model ◽  
Analysis Method ◽  
Class Iii ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Clinical Changes

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.

Three-Dimensional Finite Element Analysis of Skin-Pass Rolling and New Models for Process Control

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Sung Jin Yoon ◽  
Tae Jin Shin ◽  
Jae Sang Lee ◽  
Sang Moo Hwang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Coupled Analysis ◽  
Stress Profile ◽  
Fe Model ◽  
Element Analysis ◽  
Skin Pass ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

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.

scholarly journals The biomechanical effect of the relevant segments after facet-disectomy in different diameters under posterior lumbar percutaneous endoscopes: a three-dimensional finite element analysis

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yin Shi ◽  
Yi-Zhou Xie ◽  
Qun Zhou ◽  
Yang Yu ◽  
Xiao-Hong Fan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Mechanical Effect ◽  
Fe Model ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Left And Right ◽  
Different Diameters ◽  
Three Dimensional Finite Element ◽  
Lumbar Facetectomy

Abstract Objective To evaluate the biomechanical influence after percutaneous endoscopic lumbar facetectomy in different diameters on segmental range of motion (ROM) and intradiscal pressure (IDP) of the relevant segments by establishing three dimensional finite element (FE) model. Methods An intact L3–5 model was successfully constructed from the CT of a healthy volunteer as Model A (MA). The Model B (MB), Model C (MC) and Model D (MD) were obtained through facetectomy on L4 inferior facet in diameters 7.5 mm, 10 mm and 15 mm on MA for simulation. The ROM and IDP of L3/4 and L4/5 of four models were all compared in forward flexion, backward extension, left and right bending, left and right rotation. Results Compared with MA, the ROM of L4/5 of MB, MC and MD all increased. MD changed more significantly than MB and MC in backward extension, right bending and right rotation. But that of MB and MC on L3/4 had no prominent change, while MD had a slight increase in backward extension. The IDP of MB and MC on L4/5 in six states was similar to MA, yet MD increased obviously in backward extension, right bending, left and right rotation. The IDP on L3/4 of MB and MC was resemble to MA in six conditions, nevertheless MD increased slightly only in backward extension. Conclusion Compared with the facetectomy in diameters 7.5 mm and 10 mm, the mechanical effect brought by facetectomy in diameter 15 mm on the operating segment changed more significantly, and had a corresponding effect on the adjacent segments.

scholarly journals Application of Equivalent Elastic Methods in Three-Dimensional Finite Element Structural Analysis

1999 ◽  
Vol 121 (3) ◽  
pp. 283-290 ◽  
Author(s):  
D. P. Jones ◽  
J. L. Gordon ◽  
D. N. Hutula ◽  
J. E. Holliday ◽  
W. G. Jandrasits
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Efficient Solutions ◽  
Constitutive Relationship ◽  
Fe Model ◽  
Sample Problem ◽  
Element Analysis ◽  
Elastic Symmetry ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper describes use of equivalent solid (EQS) modeling to obtain efficient solutions to perforated material problems using three-dimensional finite element analysis (3-D-FEA) programs. It is shown that EQS modeling in 3-D-FEA requires an EQS constitutive relationship with a sufficient number of independent constants to allow the EQS material to respond according to the elastic symmetry of the penetration pattern. It is also shown that a 3-D-FEA submodel approach to calculate peak stresses and ligament stresses from EQS results is very accurate and preferred over more traditional stress multiplier approaches. The method is demonstrated on the problem of a transversely pressurized simply supported plate with a central divider lane separating two perforated regions with circular penetrations arranged in a square pattern. A 3-D-FEA solution for a model that incorporates each penetration explicitly is used for comparison with results from an EQS solution for the plate. Results for deflection and stresses from the EQS solution are within 3 percent of results from the explicit 3-D-FE model. A solution to the sample problem is also provided using the procedures in the ASME B&PV Code. The ASME B&PV Code formulas for plate deflection were shown to overestimate the stiffening effects of the divider lane and the outer stiffening ring.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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