Interface Shear Behavior of Landfill Composite Liner Systems: A Finite Element Analysis

A significant problem with rigid prosthetic stems applied in the finger bones, as well as in other bones of the upper and lower extremity, is resorption of bone at the interface. An investigation was carried out using a plastic plug which would more evenly distribute the stresses to the bone, with fine ridges to produce enhanced fixation by bony ingrowth. A total knee prosthesis in the cat was used as the model, radiographic and histological studies being made at up to one year. A finite element analysis identified areas of high interface and material stresses. With a finely grooved plug, bone ingrowth occurred in all regions except for the region near the bone entry, where the finite element analysis showed the highest interface shear stresses and bone material stresses to occur.

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A Computational Model to Describe the Regional Interlamellar Shear of the Annulus Fibrosus

Journal of Biomechanical Engineering ◽

10.1115/1.4027061 ◽

2014 ◽

Vol 136 (5) ◽

Cited By ~ 12

Author(s):

Kevin M. Labus ◽

Sang Kuy Han ◽

Adam H. Hsieh ◽

Christian M. Puttlitz

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Finite Element Model ◽

Annulus Fibrosus ◽

Element Model ◽

Shear Behavior ◽

Intervertebral Disk ◽

Element Analysis ◽

Physical Experiments ◽

The Finite Element Model

Interlamellar shear may play an important role in the homeostasis and degeneration of the intervertebral disk. Accurately modeling the shear behavior of the interlamellar compartment would enhance the study of its mechanobiology. In this study, physical experiments were utilized to describe interlamellar shear and define a constitutive model, which was implemented into a finite element analysis. Ovine annulus fibrosus (AF) specimens from three locations within the intervertebral disk (lateral, outer anterior, and inner anterior) were subjected to in vitro mechanical shear testing. The local shear stress–stretch relationship was described for the lamellae and across the interlamellar layer of the AF. A hyperelastic constitutive model was defined for interlamellar and lamellar materials at each location tested. The constitutive models were incorporated into a finite element model of a block of AF, which modeled the interlamellar and lamellar layers using a continuum description. The global shear behavior of the AF was compared between the finite element model and physical experiments. The shear moduli at the initial and final regions of the stress–strain curve were greater within the lamellae than across the interlamellar layer. The difference between interlamellar and lamellar shear was greater at the outer anterior AF than at the inner anterior region. The finite element model was shown to accurately predict the global shear behavior or the AF. Future studies incorporating finite element analysis of the interlamellar compartment may be useful for predicting its physiological mechanical behavior to inform the study of its mechanobiology.

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