Single-trabecula building block for large-scale finite element models of cancellous bone

2004 ◽  
Vol 42 (4) ◽  
pp. 549-556 ◽  
Author(s):  
D. Dagan ◽  
M. Be'ery ◽  
A. Gefen
2001 ◽  
Vol 123 (5) ◽  
pp. 403-409 ◽  
Author(s):  
Taiji Adachi ◽  
Ken-ichi Tsubota ◽  
Yoshihiro Tomita ◽  
Scott J. Hollister

A computational simulation method for three-dimensional trabecular surface remodeling was proposed, using voxel finite element models of cancellous bone, and was applied to the experimental data. In the simulation, the trabecular microstructure was modeled based on digital images, and its morphological changes due to surface movement at the trabecular level were directly expressed by removing/adding the voxel elements from/to the trabecular surface. A remodeling simulation at the single trabecular level under uniaxial compressive loading demonstrated smooth morphological changes even though the trabeculae were modeled with discrete voxel elements. Moreover, the trabecular axis rotated toward the loading direction with increasing stiffness, simulating functional adaptation to the applied load. In the remodeling simulation at the trabecular structural level, a cancellous bone cube was modeled using a digital image obtained by microcomputed tomography (μCT), and was uniaxially compressed. As a result, the apparent stiffness against the applied load increased by remodeling, in which the trabeculae reoriented to the loading direction. In addition, changes in the structural indices of the trabecular architecture coincided qualitatively with previously published experimental observations. Through these studies, it was demonstrated that the newly proposed voxel simulation technique enables us to simulate the trabecular surface remodeling and to compare the results obtained using this technique with the in vivo experimental data in the investigation of the adaptive bone remodeling phenomenon.


Author(s):  
Yener N. Yeni ◽  
Do-Gyoon Kim ◽  
Roger R. Zauel ◽  
Evan M. Johnson ◽  
Dianna D. Cody

Vertebral fractures are among the most common and debilitating fractures. Structural organization of cancellous and cortical bone in a vertebra and their local properties are important factors that determine the strength of a vertebra. Linear finite element models utilizing Quantitative Computed Tomography (QCT) images have proven useful for predicting vertebral strength and are potentially useful in predicting risk of fracture in a clinical setting [1]. However, the amount of architectural detail in these models is not sufficient for studying trabecular stress and strains, and their relationship with the microscopic structure, which is important for understanding the mechanisms behind vertebral fragility.


1996 ◽  
Author(s):  
Francois Hemez ◽  
Charbel Farhat ◽  
Emmanuele Decaux ◽  
Jacques Duysens ◽  
Pascal L

2009 ◽  
Vol 45 (3) ◽  
pp. 1108-1111 ◽  
Author(s):  
A. Schultschik ◽  
O. Farle ◽  
R. Dyczij-Edlinger

2003 ◽  
Vol 125 (4) ◽  
pp. 623-631 ◽  
Author(s):  
E. P. Petrov ◽  
D. J. Ewins

The problem of determining the worst mistuning patterns is formulated and solved as an optimization problem. Maximum resonant amplitudes searched across the many nodes of a large-scale finite element model of a mistuned bladed disk and across all the excitation frequencies in a given range are combined into an objective function. Individual blade mistuning is controlled by varying design parameters, whose variation range is constrained by manufacture tolerances. Detailed realistic finite element models, which have so far only been used for analyzing tuned bladed disks, are used for calculation of the forced resonant response of mistuned assemblies and for determination of its sensitivity coefficients with respect to mistuning variation. Results of the optimum search of mistuning patterns for some practical bladed disks are analyzed and reveal higher worst cases than those found in previous studies.


Author(s):  
E. P. Petrov ◽  
D. J. Ewins

In the paper, the problem of determining of the worst mistuning patterns is formulated and solved as an optimization problem. Maximum resonant amplitudes searched across the many nodes of a large-scale finite element model of a mistuned bladed disc and across all the excitation frequencies in a given range are combined into an objective function. Individual blade mistuning is controlled by varying design parameters, whose variation range is constrained by manufacture tolerances. Detailed realistic finite element models, which have so far only been used for analysing tuned bladed discs, are used for calculation of the forced resonant response of mistuned assemblies and for determination of its sensitivity coefficients with respect to mistuning variation. Results of the optimum search of mistuning patterns for some practical bladed discs are analysed and reveal higher worst cases than those found in previous studies.


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