Finite element analysis of idealised unit cell cancellous structure based on morphological indices of cancellous bone

2010 ◽  
Vol 48 (5) ◽  
pp. 497-505 ◽  
Author(s):  
Mohammed Rafiq Abdul Kadir ◽  
Ardiyansyah Syahrom ◽  
Andreas Öchsner
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cancellous Bone ◽  
Unit Cell ◽  
Element Analysis ◽  
Morphological Indices

Experimental and numerical study on stiffness and damage of glass/epoxy biaxial weft-knitted reinforced composites

2020 ◽  
pp. 073168442093844 ◽  
Author(s):  
Navid Shekarchizadeh ◽  
Reza Jafari Nedoushan ◽  
Tohid Dastan ◽  
Hossein Hasani
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Study ◽  
Unit Cell ◽  
Analytical Equation ◽  
Reinforced Composites ◽  
Element Analysis ◽  
Composite Strength ◽  
Failure Theories ◽  
Meso Scale

This paper deals with investigating the tensile characteristics of biaxial weft-knitted reinforced composites in terms of stiffness, strength and failure mechanism. The biaxial weft-knitted fabric was produced on an electronic flat knitting machine by E-glass yarns and then was impregnated with epoxy resin. Using an accurate geometrical model, the composite unit cell was designed in Abaqus software’s environment. Tensile tests were simulated in different directions on the created unit cell and the stiffness was calculated. By applying the proper failure theories, the composite strength was predicted and then critical regions of the unit cell were determined. In the next step, a micromechanical approach was also applied to estimate the same tensile features. Failure theories were also applied to predict the strength and most susceptible areas for failure phenomenon in the composite unit cell. The tensile properties of the produced composites were measured and compared with outputs of the finite element and micromechanical approaches. The results showed that the meso-scale finite element analysis approach can well predict the composite strength. In contrast, the meso-scale analytical equation model was not able to predict it acceptably because this model ignores the strain concentration. Both meso-scale finite element analysis and meso-scale analytical equation approaches predicted the similar locations for the composite failure in wale and course directions.

scholarly journals Influence of PEEK Coating on Hip Implant Stress Shielding: A Finite Element Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jesica Anguiano-Sanchez ◽  
Oscar Martinez-Romero ◽  
Hector R. Siller ◽  
Jose A. Diaz-Elizondo ◽  
Eduardo Flores-Villalba ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cancellous Bone ◽  
Stress Shielding ◽  
Design Concept ◽  
Von Mises Stress ◽  
Hip Implants ◽  
Element Analysis ◽  
Stress Transmission ◽  
Von Mises

Stress shielding is a well-known failure factor in hip implants. This work proposes a design concept for hip implants, using a combination of metallic stem with a polymer coating (polyether ether ketone (PEEK)). The proposed design concept is simulated using titanium alloy stems and PEEK coatings with thicknesses varying from 100 to 400 μm. The Finite Element analysis of the cancellous bone surrounding the implant shows promising results. The effective von Mises stress increases between 81 and 92% for the complete volume of cancellous bone. When focusing on the proximal zone of the implant, the increased stress transmission to the cancellous bone reaches between 47 and 60%. This increment in load transferred to the bone can influence mineral bone loss due to stress shielding, minimizing such effect, and thus prolonging implant lifespan.

scholarly journals Analysis of cold formed steel sheet pile for earth retaining wall

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
C. Veena ◽  
S Saravanan ◽  
Robin Davis P. ◽  
Nandakumar Gopalan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Load ◽  
Unit Cell ◽  
Bending Stress ◽  
Sheet Pile ◽  
Element Analysis ◽  
Cold Formed Steel

Failure loads of sheet pile having various profiles such as U, Z and Omega/Hat profiles under compression was carried out by using equations of strength of materials and compared the failure load under various modes such as Euler’s buckling, torsional buckling and failure load due to yielding. Compared the strength of various profiles under flexure by using finite element analysis. Sheet pile can be analyzed as a unit cell for the simplified finite element analysis. For selecting the unit cell sheet pile with omega/Hat section was analyzed for profile containing one to eight numbers and checked the convergence of bending stress and maximum lateral deflection. Interlocks were analyzed for three different conditions such as plane interlock, interlock filled with bitumen and welded interlock. Location of interlock and neutral axis of the wall will affect the stability of the structure. Sheet piles with various cross sections were analyzed and studied the shear stress and bending stress along the cross section. From the structural performance of various cross sections omega/hat section can be considered as the most efficient cross section for the cold formed steel sheet pile because of its more load carrying capacity under compression and high torsion resistance and less bending stress. Results from the finite element analysis for the selection of unit cell shows that the stress and deflection value was converge at the sheet pile having 6 numbers of profiles. Keywords: sheet piles, building, resistance.

Adaptive remodeling at the pedicle due to pars fracture: a finite element analysis study

2014 ◽  
Vol 21 (3) ◽  
pp. 475-480
Author(s):  
Serkan İnceoğlu ◽  
Prasath Mageswaran ◽  
Michael T. Modic ◽  
Edward C. Benzel
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cancellous Bone ◽  
Element Model ◽  
Common Condition ◽  
Young Athletes ◽  
Element Analysis ◽  
Multiscale Finite Element ◽  
Pars Fracture ◽  
Loss Of Mass

Object Spondylolysis is a common condition among the general population and a major cause of back pain in young athletes. This condition can be difficult to detect with plain radiography and has been reported to lead to contralateral pars fracture or pedicle fracture in the terminal stages. Interestingly, some patients with late-stage spondylolysis are observed to have radiographic or CT evidence of a sclerotic pedicle on the side contralateral to the spondylolysis. Although computational studies have shown stress elevation in the contralateral pedicle after a pars fracture, it is not known if these changes would cause sclerotic changes in the contralateral pedicle. The objective of this study was to investigate the adaptive remodeling process at the pedicle due to a contralateral spondylolysis using finite element analysis. Methods A multiscale finite element model of a vertebra was obtained by combining a continuum model of the posterior elements with a voxel-based pedicle section. Extension loading conditions were applied with or without a fracture at the contralateral pars to analyze the stresses in the contralateral pedicle. A remodeling algorithm was used to simulate and assess density changes in the contralateral pedicle. Results The remodeling algorithm demonstrated an increase in bone formation around the perimeter of the contralateral pedicle with some localized loss of mass in the region of cancellous bone. Conclusions The authors' results indicated that a pars fracture results in sclerotic changes in the contralateral pedicle. Such a remodeling process could increase overall bone mass. However, focal bone loss in the region of the cancellous bone of the pedicle might predispose the pedicle to microfractures. This phenomenon explains, at least in part, the origin of pedicle stress fractures in the sclerotic contralateral pedicles of patients with unilateral spondylolysis.

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