The mechanical behavior of PMMA/bone specimens extracted from augmented vertebrae: A numerical study of interface properties, PMMA shrinkage and trabecular bone damage

2012 ◽  
Vol 45 (8) ◽  
pp. 1478-1484 ◽  
Author(s):  
M. Kinzl ◽  
A. Boger ◽  
P.K. Zysset ◽  
D.H. Pahr
2021 ◽  
Vol 138 (27) ◽  
pp. 50648 ◽  
Author(s):  
Roberto Yáñez‐Macías ◽  
Jorge E. Rivera‐Salinas ◽  
Silvia Solís‐Rosales ◽  
Daniel Orduña‐Altamirano ◽  
David Ruíz‐Mendoza ◽  
...  

2015 ◽  
Vol 27 (04) ◽  
pp. 1550033 ◽  
Author(s):  
Mahdi Halabian ◽  
Alireza Karimi ◽  
Borhan Beigzadeh ◽  
Mahdi Navidbakhsh

Abdominal aortic aneurysm (AAA) is a degenerative disease defined as the abnormal ballooning of the abdominal aorta (AA) wall which is usually caused by atherosclerosis. The aneurysm grows larger and eventually ruptures if it is not diagnosed and treated. Aneurysms occur mostly in the aorta, the main artery of the chest and abdomen. The aorta carries blood flow from the heart to all parts of the body, including the vital organs, the legs, and feet. The objective of the present study is to investigate the combined effects of aneurysm and curvature on flow characteristics in S-shaped bends with sweep angle of 90° at Reynolds number of 900. The fluid mechanics of blood flow in a curved artery with abnormal aortic is studied through a mathematical analysis and employing Cosmos flow simulation. Blood is modeled as an incompressible non-Newtonian fluid and the flow is assumed to be steady and laminar. Hemodynamic characteristics are analyzed. Grid independence is tested on three successively refined meshes. It is observed that the abrupt expansion induced by AAA results in an immensely disturbed regime. The results may have implications not only for understanding the mechanical behavior of the blood flow inside an aneurysm artery but also for investigating the mechanical behavior of the blood flow in different arterial diseases, such as atherosclerosis.


2019 ◽  
Vol 5 (6) ◽  
pp. 065023
Author(s):  
A E Bravo ◽  
L C Osnaya ◽  
E I Ramírez ◽  
V H Jacobo ◽  
A Ortiz

2015 ◽  
Vol 51 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Klaus Fellner ◽  
Thomas Antretter ◽  
Peter F Fuchs ◽  
Tiphaine Pélisset

Author(s):  
Elizabeth Weiss

This chapter introduces readers to the basics of understanding bone’s functions, which include calcium homeostasis and enabling movement, bone’s components, such as the collagen, and bone’s organization, such as the Haversian system found in cortical bone. The focus of this chapter is on explaining concepts of bone remodeling, which is thought to prevent fractures and other bone damage, and repair, which can take place at macro-levels and micro-levels. Wolff’s Law of bone remodeling, which was initially focused on trabecular bone changes, is discussed in terms of bone’s response to forces that result in strains and stresses. Finally, diarthrodial joint remodeling and repair are discussed; cartilage cells were once thought to be static, yet now they are known to also respond to stresses.


1998 ◽  
Vol 02 (02) ◽  
pp. 167-180 ◽  
Author(s):  
Tae-Hong Lim ◽  
Jung Hwa Hong

A one-dimensional poroelastic model of trabecular bone was developed to investigate the fluid effect on the mechanical behavior at the continuum level. The poroelastic properties were determined based upon an assumed drained Poisson's ratio of 0.3 and experimental results reported in the literature. Even though the free escape of the fluid through the loading end was allowed during deformation, model predictions showed that the pore pressure generated within trabecular bone would cause significant variations in total stress. The total stress increase resulted in a stiffening of trabecular bone, which supports the concept of hydraulic stiffening that has been advocated by several investigators. Model predictions showed a good agreement to the mechanical behaviors of trabecular bone specimens with marrow in situ in a uniaxial strain condition observed in previous studies. These results support the hypothesis that trabecular bone is poroelastic and the fluid effect on the mechanical behavior at the continnum level is significant. Thus, the incorporation of the fluid effect in future studies is recommended to improve our understanding of mechanical behavior of trabecular bone.


Author(s):  
Nitin Garg ◽  
Gurudutt Chandrashekar ◽  
Farid Alisafaei ◽  
Chung-Souk Han

Abstract Microbeam bending and nano-indentation experiments illustrate that length scale-dependent elastic deformation can be significant in polymers at micron and submicron length scales. Such length scale effects in polymers should also affect the mechanical behavior of reinforced polymer composites, as particle sizes or diameters of fibers are typically in the micron range. Corresponding experiments on particle-reinforced polymer composites have shown increased stiffening with decreasing particle size at the same volume fraction. To examine a possible linkage between the size effects in neat polymers and polymer composites, a numerical study is pursued here. Based on a couple stress elasticity theory, a finite element approach for plane strain problems is applied to predict the mechanical behavior of fiber-reinforced epoxy composite materials at micrometer length scale. Numerical results show significant changes in the stress fields and illustrate that with a constant fiber volume fraction, the effective elastic modulus increases with decreasing fiber diameter. These results exhibit similar tendencies as in mechanical experiments of particle-reinforced polymer composites.


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