Validation of an In Vivo Medical Image-Based Young Human Lumbar Spine Finite Element Model

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Matthew J. Mills ◽  
Nesrin Sarigul-Klijn
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Medical Image ◽  
Female Subject ◽  
Element Model ◽  
Young Female ◽  
Lumbosacral Spine ◽  
Finite Element Models ◽  
The Finite Element Model

Mathematical models of the human spine can be used to investigate spinal biomechanics without the difficulties, limitations, and ethical concerns associated with physical experimentation. Validation of such models is necessary to ensure that the modeled system behavior accurately represents the physics of the actual system. The goal of this work was to validate a medical image-based nonlinear lumbosacral spine finite element model of a healthy 20-yr-old female subject under physiological moments. Range of motion (ROM), facet joint forces (FJF), and intradiscal pressure (IDP) were compared with experimental values and validated finite element models from the literature. The finite element model presented in this work was in good agreement with published experimental studies and finite element models under pure moments. For applied moments of 7.5 N·m, the ROM in flexion–extension, axial rotation, and lateral bending were 39 deg, 16 deg, and 28 deg, respectively. Excellent agreement was observed between the finite element model and experimental data for IDP under pure compressive loading. The predicted FJFs were lower than those of the experimental results and validated finite element models for extension and torsion, likely due to the nondegenerate properties chosen for the intervertebral disks and morphology of the young female spine. This work is the first to validate a computational lumbar spine model of a young female subject. This model will serve as a valuable tool for predicting orthopedic spinal injuries, studying the effect of intervertebral disk replacements using advanced biomaterials, and investigating soft tissue degeneration.

scholarly journals The Finite Element Model of Seated Whole Human Body for Vibration Investigations of Lumbar Spine in Complex System

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 125046-125055
Author(s):  
Rui-Chun Dong ◽  
Qian-Jian Guo ◽  
Wei Yuan ◽  
Wei Du ◽  
Xian-Hai Yang ◽  
...  
Keyword(s):  
Complex System ◽  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Human Body ◽  
Element Model ◽  
The Finite Element Model

scholarly journals ANALYSIS OF FEATURES OF APPLIED SOFTWARE “LIRA” IN CALCULATIONS OF NON-CIRCULAR TUNNEL LININGS

2019 ◽  
pp. 41-50
Author(s):  
V. P. KUPRIY ◽  
O. L. TIUTKIN ◽  
P. YE. ZAKHARCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Software Package ◽  
Strain State ◽  
Element Model ◽  
Finite Element Models ◽  
Stress Strain ◽  
Stress Strain State ◽  
The Finite Element Model

Purpose. The article examines the effect on the stress-strain state of the parameters of the finite-element model created in the “Lira” software package in a numerical analysis of non-circular outlined tunnels. Methodology To achieve this goal, the authors developed finite element models of the calotte part of the mine during the construction of a double track railway tunnel using “Lira” software. In each of the models in the “Lira” software package, the interaction zone with temporary fastening was sampled in a specific way. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. In the finite element models, the values of deformations and stresses in the horizontal and vertical axes, as well as the maximum values of the moments and longitudinal forces in the temporary fastening were obtained. A comparative analysis of the obtained values of the components of the stress-strain state with a change in the parameters of the finite element model was carried out. The graphs of the laws of these results from the discretization features of the two models were plotted. The third finite element model with a radial meshing in the zone of interaction of temporary support with the surrounding soil massif was investigated. Originality It has been established that in the numerical analysis of the SSS of a tunnel lining of a non-circular outline, its results substantially depend on the shape, size and configuration of the applied finite elements, on the size of the computational area of the soil massif, and also on the conditions for taking into account the actual (elastic or plastic) behavior of the soil massif.  Practical value. The features of discretization and the required dimensions of the computational area of the soil massif were determined when modeling the “lining – soil massif” system, which provide sufficient accuracy for calculating the parameters of the stress-strain state of the lining.

scholarly journals Finite Element Model Updating of Reinforced Concrete Beams with Honeycomb Damage

2012 ◽  
Vol 58 (2) ◽  
pp. 135-151 ◽  
Author(s):  
Z. Ismail
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Model ◽  
Model Updating ◽  
Element Model ◽  
Significant Loss ◽  
Reinforced Concrete Beams ◽  
Finite Element Model Updating ◽  
Finite Element Models ◽  
The Finite Element Model

Abstract A method of detecting honeycombing damage in a reinforced concrete beam using the finite element model updating technique was proposed. A control beam and two finite element models representing different severity of damage were constructed using available software and the defect parameters were updated. Analyses were performed on the finite element models to approximate the modal parameters. A datum and a control finite element model to match the datum test beams with honeycombs were prepared. Results from the finite element model were corrected by updating the Young’s modulus and the damage parameters. There was a loss of stiffness of 3% for one case, and a loss of 7% for another. The more severe the damage, the higher the loss of stiffness. There was no significant loss of stiffness by doubling the volume of the honeycombs.

Adaptive Finite Element Methods: A Review

1997 ◽  
Vol 50 (10) ◽  
pp. 581-591 ◽  
Author(s):  
Long-yuan Li ◽  
Peter Bettess
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Adaptive Finite Element Method ◽  
Finite Element Models ◽  
Adaptive Finite Element ◽  
Element Discretization ◽  
New Model ◽  
Discretization Errors ◽  
The Finite Element Model

The adaptive finite element method (FEM) was developed in the early 1980s. The basic concept of adaptivity developed in the FEM is that, when a physical problem is analyzed using finite elements, there exist some discretization errors caused owing to the use of the finite element model. These errors are calculated in order to assess the accuracy of the solution obtained. If the errors are large, then the finite element model is refined through reducing the size of elements or increasing the order of interpolation functions. The new model is re-analyzed and the errors in the new model are recalculated. This procedure is continued until the calculated errors fall below the specified permissible values. The key features in the adaptive FEM are the estimation of discretization errors and the refinement of finite element models. This paper presents a brief review of the methods for error estimates and adaptive refinement processes applied to finite element calculations. The basic theories and principles of estimating finite element discretization errors and refining finite element models are presented. This review article contains 131 references.

scholarly journals The method of synthesis of finite-element model of strengthened fuselage frames

2013 ◽  
pp. 80-90
Author(s):  
В. В. Борисов ◽  
В. В. Сухов
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Model ◽  
User Interfaces ◽  
Element Model ◽  
Finite Element Models ◽  
Synthesis Algorithm ◽  
Model Synthesis ◽  
Aircraft Fuselage ◽  
The Finite Element Model

One of the main problems, which solved during the design of transport category aircraft, is problem of analysis of the stress distribution in the strengthened fuselage frames structure. Existing integral methods of stress analysis does not allow for the mutual influence of the deformation of a large number of elements. The most effective method of solving the problem of analysis of deformations influence on the stress distribution of structure is finite element method, which is a universal method for analyzing stress distribution arbitrary constructions.This article describes the features of the finite element model synthesis of the strengthened fuselage frames structure of the aircraft fuselage transport category. It is shown that the finite element model of strengthened frames can be synthesized by attaching additional finite element models of the reinforcing elements to the base finite element model which is built by algorithm which is developed for normal frame. For each reinforcing element developed a separate class of finite element model synthesis algorithm. The method of synthesis of finite element model of strengthened frame, which are described in this article, developed for object-oriented information technology implemented in an object-oriented data management system "SPACE".Finite-element models of the reinforcing elements are included in the finite element model of the fuselage box after the formation of a regular finite element model of the fuselage box. As the source data for the synthesis of finite element models of the reinforcing elements used the coordinates of the boundary sections nodes of existing finite element models of conventional frames.Reinforcing elements belong to the group of irregular structural elements that connect regular elements of the cross set with different elements that are not intended for the perception and transmission of loads. The only exceptions are the vertical amplification increasing the stiffness of  frames in a direction parallel to the axis OY.Source data input for the synthesis of finite element models of the reinforcing elements can occur only through the individual user interfaces that supported by objects of the corresponding classes. Structure of user interfaces depends on the number and type of additional data that required for the synthesis of finite element models of the reinforcing elements. For example, for the synthesis of structures of finite element models of horizontal beams that support the floor of cargo cabin, you must specify the distance between the upper surface of the beam and the horizontal axis of the fuselage, as well as the height of the beam section. For the synthesis of the structure of the finite element model of vertical reinforcing element is enough to specify the distance between the its inner belt and the a vertical axis of symmetry of the fuselage.And in both cases you must to specify a reference to the basic finite element model, by selecting from a list of frame designations. List of frames, as well as links to objects containing the appropriate finite-element models, must be transmitted from an object which references to the level of decomposition, in which the general model of the fuselage box is created.Finite-element models of the reinforcing elements include two groups of nodes. The first group is taken from an array of nodes, which is transmitted from the base finite element model. The second group is formed by the synthesis algorithm of finite element model of the selected class reinforcing element. Therefore, the synthesis of finite element models of the reinforcing elements starts with the formation of their local model versions. On the basis of these models are formed temporary copies, which are transmitted to the general finite element model of the box. This should be considered when developing of data conversion algorithm of data copying from a local finite element model to the temporary copy.Based on this analysis, we can conclude that this method improves the quality of the design of the aircraft fuselage, increasing the amount of structure variant number and reduce the likelihood of errors.

Improvement of Hood Hinge Based on Protection of Pedestrian Head

2011 ◽  
Vol 228-229 ◽  
pp. 119-124
Author(s):  
Zheng Cai Hu ◽  
Duo Nian Yu ◽  
Liu Hang ◽  
Fang Zhi Feng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Traffic Accident ◽  
Element Model ◽  
Test Area ◽  
Finite Element Models ◽  
Adult Head ◽  
The Finite Element Model

This paper established finite element models of adult head based on GB/T 24550-2009 and hood of a car. When the finite element model of the adult headform impactor was established, tests were carried out to prove that the impactor was valid. Then experiments were carried out at adult head test area of the hood. The results show that some areas of the hood are too hard where the hood hinges are installed. It is very bad for pedestrian head to hit those areas in accident. In order to protect pedestrian head efficiently, this paper proposed a new kind of hood hinge, called buffer-type hinge. Comparison tests were carried out. The buffer-type hinge is proved to be more effective to protect pedestrian head in traffic accident.

Research on the Key Technologies for Establishing the Finite Element Model of a Gyro-Stabilized Platform

2015 ◽  
Vol 742 ◽  
pp. 603-607
Author(s):  
Xiu Li Yang ◽  
Lin Jing Qin ◽  
Feng Xiao Huang ◽  
Wen Jing Guo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Mode Analysis ◽  
Finite Element Models ◽  
Three Dimensional Model ◽  
Modeling And Analysis ◽  
Stabilized Platform ◽  
The Finite Element Model

The gyro-stabilized platform is one of the key parts of a guidance weapon. The structure performance of a platform influences the accuracy and reliability of the guidance weapon straightly. In order to reduce development cost and time, the structural modeling and analysis of gyro stabilized platform is very necessary. UG software is applied to establish the three-dimensional model of a platform firstly. And then some components are simplified using MSC Patron. According to the different connection mode between the components, some appropriate connecting elements are applied to establish the finite element model of the platform. In order to meet the special requirements of individual components, appropriate materials are selected so that the finite element model is closer to the actual situation which ensures the reliability of mode analysis and optimized computing results. The work in this paper provides reference for establishment of the similar structure finite element models.

scholarly journals Sensitivity Analysis of the Influence of Structural Parameters on Dynamic Behaviour of Highly Redundant Cable-Stayed Bridges

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Structural Parameters ◽  
Element Model ◽  
Structural Behavior ◽  
Model Tuning ◽  
The Finite Element Model ◽  
Cable Stayed Bridges

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.

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