Haptically integrated simulation of a finite element model of thoracolumbar spine combining offline biomechanical response analysis of intervertebral discs

2010 ◽  
Vol 42 (12) ◽  
pp. 1151-1166 ◽  
Author(s):  
Kim Tho Huynh ◽  
Zhan Gao ◽  
Ian Gibson ◽  
Wen Feng Lu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Thoracolumbar Spine ◽  
Element Model ◽  
Intervertebral Discs ◽  
Response Analysis ◽  
Integrated Simulation ◽  
Biomechanical Response

scholarly journals Design optimization of vehicle asynchronous motors based on fractional harmonic response analysis

2021 ◽  
Vol 12 (1) ◽  
pp. 689-700
Author(s):  
Ao Lei ◽  
Chuan-Xue Song ◽  
Yu-Long Lei ◽  
Yao Fu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Natural Frequency ◽  
Asynchronous Motor ◽  
Element Model ◽  
Design Parameters ◽  
Response Analysis ◽  
Harmonic Response ◽  
First Order ◽  
Harmonic Response Analysis

Abstract. To make vehicles more reliable and efficient, many researchers have tried to improve the rotor performance. Although certain achievements have been made, the previous finite element model did not reflect the historical process of the motor rotor well, and the rigidity and mass in rotor optimization are less discussed together. This paper firstly introduces fractional order into a finite element model to conduct the harmonic response analysis. Then, we propose an optimal design framework of a rotor. In the framework, objective functions of rigidity and mass are defined, and the relationship between high rigidity and the first-order frequency is discussed. In order to find the optimal values, an accelerated optimization method based on response surface (ARSO) is proposed to find the suitable design parameters of rigidity and mass. Because the higher rigidity can be transformed into the first-order natural frequency by objective function, this paper analyzes the first-order frequency and mass of a motor rotor in the experiment. The results proved that not only is the fractional model effective, but also the ARSO can optimize the rotor structure. The first-order natural frequency of asynchronous motor rotor is increased by 11.2 %, and the mass is reduced by 13.8 %, which can realize high stiffness and light mass of asynchronous motor rotors.

What have we learned from finite element model studies of lumbar intervertebral discs in the past four decades?

2013 ◽  
Vol 46 (14) ◽  
pp. 2342-2355 ◽  
Author(s):  
Hendrik Schmidt ◽  
Fabio Galbusera ◽  
Antonius Rohlmann ◽  
Aboulfazl Shirazi-Adl
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Intervertebral Discs ◽  
Model Studies ◽  
The Past

Frequency Window Implementation of Adaptive Multi-Level Substructuring

1998 ◽  
Vol 120 (2) ◽  
pp. 409-418 ◽  
Author(s):  
J. K. Bennighof ◽  
M. F. Kaplan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Center Frequency ◽  
Response Analysis ◽  
Adaptive Procedure ◽  
Multi Level ◽  
Frequency Window ◽  
Efficient Representation ◽  
Multiple Levels

Adaptive multi-level substructuring (AMLS) is a method for reducing the order of a complex structure’s finite element model by orders of magnitude, while ensuring that the accuracy available from the original model is preserved. A structure’s finite element model is transformed to a much more efficient representation in terms of approximate vibration modes for substructures on multiple levels. An adaptive procedure constructs an optimal model for satisfying a user-specified error tolerance, by determining which modes should be included in the model. In this paper, a frequency window implementation of AMLS is developed, in which frequency response analysis can be done over a frequency window at little additional cost beyond that of the center frequency solution. A numerical example is presented.

Finite Element Analysis of Fixation System Influence on the Thoracolumbar Spine Stability

2016 ◽  
Vol 821 ◽  
pp. 685-692 ◽  
Author(s):  
Klaudia Szkoda ◽  
Celina Pezowicz
Keyword(s):  
Finite Element ◽  
Sagittal Plane ◽  
Thoracolumbar Spine ◽  
Element Model ◽  
Intervertebral Discs ◽  
Vertebral Compression Fractures ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Transpedicular Fixation ◽  
The Stability

All segments of the spine are characterized by a corresponding curvature in the sagittal plane and different geometrical parameters of vertebrae, which affects the complicated structure of transition between subsequent segments. The aim of the study was to assess changes occurring in the thoracolumbar spine, as a result of application of the transpedicular fixation. The research was conducted on finite element model, which was constructed on the basis of CT images. Five different configurations of the model were analyzed: focusing on vertebral compression fractures and degeneration of intervertebral discs. The analysis showed that the highest displacement occurred for a segment with intervertebral disc degeneration. Transpedicular fixation of injured thoracolumbar spine is given the opportunity to improve the stability and stiffness of the segment under consideration.

scholarly journals Analysis of Stationary Random Responses for Non-Parametric Probabilistic Systems

2010 ◽  
Vol 17 (3) ◽  
pp. 305-315 ◽  
Author(s):  
Y. Zhao ◽  
Y.H. Zhang ◽  
J.H. Lin ◽  
W.P. Howson ◽  
F.W. Williams
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Physical Structure ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Random Matrix Model ◽  
Stiffness Matrices ◽  
Element Technique ◽  
Non Parametric

The move from conceptual design, through fabrication to observation and measurement on the resulting physical structure is fraught with uncertainty. This, together with the necessary simplifications inherent when using the finite element technique, makes the development of a predictive model for the physical structure sufficiently approximate that the use of random structural models is often to be preferred. In this paper, the random uncertainties of the mass, damping and stiffness matrices in a finite element model are replaced by random matrices, and a highly efficient pseudo excitation method for the dynamic response analysis of non-parametric probability systems subjected to stationary random loads is developed. A numerical example shows that the dynamic responses calculated using a conventional (mean) finite element model may be quite different from those based on a random matrix model. For precise fabrication, the uncertainties of models cannot be ignored and the proposed method should be useful in the analysis of such problems.

Frequency Window Implementation of Adaptive Multi-Level Substructuring

1995 ◽  
Author(s):  
Jeffrey K. Bennighof ◽  
Matthew F. Kaplan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Center Frequency ◽  
Response Analysis ◽  
Adaptive Procedure ◽  
Multi Level ◽  
Frequency Window ◽  
Efficient Representation ◽  
Multiple Levels

Abstract Adaptive multi-level substructuring (AMLS) is a method for reducing the order of models of complex structures by orders of magnitude, while ensuring that the accuracy available from the original finite element model is preserved. A structure’s finite element model is transformed to a much more efficient representation in terms of approximate vibration modes for substructures on multiple levels. An adaptive procedure constructs an optimal model for satisfying a user-specified error tolerance, by determining which modes should be included in the model. In this paper, a frequency window implementation of AMLS is developed, in which frequency response analysis can be done over a frequency window at little additional cost beyond that of the solution at the center frequency. A numerical example is presented.

Establishment and validation of finite element model of ossification of cervical posterior longitudinal ligament with intervertebral fusion

2020 ◽  
Author(s):  
Li Hui ◽  
Liu Huiqing ◽  
Zhang Yaning
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Posterior Longitudinal Ligament ◽  
Intervertebral Discs ◽  
Biomechanical Analysis ◽  
Intervertebral Fusion ◽  
Dimensional Finite Element

Abstract [Background ]: To establish a three-dimensional finite element model of ossification of the posterior longitudinal ligament of the cervical spine with intervertebral fusion and verify its effectiveness, and provide a platform for finite element calculation and biomechanical analysis in the later stage.[Method]: Select the Department of Spinal Surgery, Linfen People's Hospital A volunteer imported 719 DICOM format images of cervical spine CT scans into Mimics modeling software to build a preliminary 3D model in the stl format, and used Geomagic Studio 2013 software to refine and refine the 3D model to smooth out noise and generate NURBS surfaces The model was then imported into the finite element analysis software Ansys workbench 15.0, adding ligaments and intervertebral discs, meshing, assigning material properties, and simulating 6 activities of the human cervical spine, and comparing them with references.[Results]: A total of 7 Cervical vertebral body, 1 thoracic vertebral body, 5 intervertebral discs and ligaments, etc., with a total of 320512 nodes and 180905 units. It has a realistic appearance, high degree of detail reduction, and ossification of the cervical longitudinal longitudinal ligament with good geometric similarity Incorporate a three-dimensional finite element model of intervertebral fusion. In flexion and extension, left and right lateral flexion, and axial rotation activity compared with references, there is not much difference.[Conclusion]: OPLL merger interbody fusion dimensional finite element model has good mechanical and geometric similarity after similarity cervical established in this study, the model can provide a platform for the latter to further biomechanical analysis.

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