Linear Elastic Analysis of Bovine Cortical Bone under Compression Loading

2013 ◽  
Vol 845 ◽  
pp. 324-329 ◽  
Author(s):  
Theng Pin Ng ◽  
Seyed Saeid Rahimian Koloor ◽  
Joy Rizki Pangestu Djuansjah ◽  
Mohammed Rafiq Abdul Kadir
Keyword(s):  
Cortical Bone ◽  
Bone Structure ◽  
Orthopedic Implants ◽  
Computational Method ◽  
Elastic Response ◽  
Mechanical Behaviors ◽  
Compression Load ◽  
Linear Elastic ◽  
Maximum Stiffness ◽  
Experimental Process

Linear elastic response of the bovine cortical bone has been examined under compression load. Experimental and computational methods were used to observe and predict the response of cortical bone. In computational method, two mechanical behaviors of isotropic and orthotropic were considered to simulate the cortical bone deformation. In experimental process, the specimens were designed to show maximum stiffness and strength by specifying osteon direction along loading axis during tests. The tests were controlled by displacement rate of 0.5 mm/minute and the overall stiffness responses of the structures were recorded to extract mechanical properties and also for validation aims. Finite Element Method (FEM) was used to model the linear response of the structure by using ABAQUS6.9EF. The FE results using orthotropic definition shows a good correlation with experimental data. A discussion was given based on overall stiffness and effective stress variation for both mechanical behaviors. In order to design the optimal implant structure, the presented study was proposed for prediction of bone structure deformation that attached to the orthopedic implants.

scholarly journals Activated Ductile CFRP NSMR Strengthening

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2821
Author(s):  
Jacob Wittrup Schmidt ◽  
Christian Overgaard Christensen ◽  
Per Goltermann ◽  
José Sena-Cruz
Keyword(s):  
Failure Modes ◽  
Elastic Response ◽  
Applied Theory ◽  
Strengthening Effect ◽  
The Novel ◽  
Near Surface ◽  
Linear Elastic ◽  
Near Surface Mounted ◽  
High Elongation ◽  
Strengthened Beam

Significant strengthening of concrete structures can be obtained when using adhesively-bonded carbon fiber-reinforced polymer (CFRP) systems. Challenges related to such strengthening methods are; however, the brittle concrete delamination failure, reduced warning, and the consequent inefficient use of the CFRP. A novel ductile near-surface mounted reinforcement (NSMR) CFRP strengthening system with a high CFRP utilization is introduced in this paper. It is hypothesized that the tailored ductile enclosure wedge (EW) end anchors, in combination with low E-modulus and high elongation adhesive, can provide significant strengthening and ductility control. Five concrete T-beams were strengthened using the novel system with a CFRP rod activation stress of approximately 980 MPa. The beam responses were compared to identical epoxy-bonded NSMR strengthened and un-strengthened beams. The linear elastic response was identical to the epoxy-bonded NSMR strengthened beam. In addition, the average deflection and yielding regimes were improved by 220% and 300% (average values), respectively, with an ultimate capacity comparable to the epoxy-bonded NSMR strengthened beam. Reproducible and predictable strengthening effect seems obtainable, where a good correlation between the results and applied theory was reached. The brittle failure modes were prevented, where concrete compression failure and frontal overload anchor failure were experienced when failure was initiated.

scholarly journals Effect of Age on Bone Structure Parameters in Laying Hens

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 570
Author(s):  
Masayoshi Yamada ◽  
Chongxiao Chen ◽  
Toshie Sugiyama ◽  
Woo Kyun Kim
Keyword(s):  
Cortical Bone ◽  
Bone Quality ◽  
Bone Mineral ◽  
Volume Fraction ◽  
Bone Structure ◽  
Bone Volume ◽  
Egg Laying ◽  
Medullary Bone ◽  
Mineral Density ◽  
Tibial Diaphysis

Changes in medullary and cortical bone structure with age remain unclear. Twenty Hy-Line W36 hens, 25 or 52 weeks of age, were euthanized, and both tibiae were collected when an egg was present in the magnum. Serial cross sections of the tibiae were stained with Alcian blue. The bones were scanned using micro-computed tomography. Trabecular width (Tb.Wi) was significantly higher (p < 0.05) in 25-week-old hens, whereas medullary bone tissue volume (TV) was significantly higher (p < 0.01) in 52-week-old hens. 25-week-old hens had significantly higher (p < 0.01) bone volume fraction (BVF = calcified tissue / TV). Moreover, the cortical bone parameters were significantly higher (TV and bone mineral content (BMC) at p < 0.05, and bone volume (BV) and BVF at p < 0.01) in younger hens. Open porosity and total porosity, which indicate less density, were significantly higher (p < 0.01) in older hens. Older hens showed significantly higher (p < 0.01) tibial diaphysis TV than younger hens. Younger hens had significantly higher (p < 0.01) BV, BVF and bone mineral density (BMD) of the tibial diaphysis. These findings reveal that reductions in medullary bone quality might be associated with age-related low estrogen levels and stimulation of osteoclastic bone resorption by parathyroid hormone. Cortical bone quality decreased with enlargement of the Haversian canals and loss of volume, with a longer egg-laying period leading to osteoporosis.

An Experimental Study on Stretchy and Tough PDMS/Fabric Composites

2018 ◽  
Vol 86 (1) ◽  
Author(s):  
Ruofei Chang ◽  
Zhou Chen ◽  
Cunjiang Yu ◽  
Jizhou Song
Keyword(s):  
Fracture Toughness ◽  
Low Cost ◽  
Elastic Response ◽  
Deformation Localization ◽  
Practical Applications ◽  
Damage Propagation ◽  
Linear Elastic ◽  
Nylon Fabric ◽  
Fabric Composite ◽  
Fabric Composites

Polydimethylsiloxane (PDMS) has a good elasticity but with a pretty low fracture toughness, which limits its use in practical applications. This paper presents a simple and low-cost approach to manufacture a PDMS/fabric composite through incorporating the commercially available stretchy plain weft-knitted nylon fabric into the PDMS matrix. The fracture toughness of the composite is much higher than that of pure PDMS with an increase up to 700%. The toughening mechanism, which can be attributed to the deformation localization induced fiber stretch and damage propagation in the PDMS matrix, is fully investigated. During cyclic loadings, the composite may exhibit a linear elastic response or a significant hysteresis depending on the stretch level. These results provide physical insights into the deformation mechanism of a soft fabric-reinforced composite and may offer practical routes to realize robust crack-insensitive PDMS.

scholarly journals Cortical bone density by quantitative computed tomography mirrors disorders of bone structure in bone biopsy of non-dialysis CKD patients

Bone Reports ◽  
2022 ◽  
pp. 101166
Author(s):  
Amandha L. Bittencourt ◽  
Maria Eugênia F. Canziani ◽  
Larissa D.B.R. Costa ◽  
Carlos E. Rochitte ◽  
Aluizio B. Carvalho
Keyword(s):  
Computed Tomography ◽  
Bone Density ◽  
Cortical Bone ◽  
Bone Structure ◽  
Bone Biopsy ◽  
Quantitative Computed Tomography ◽  
Cortical Bone Density

scholarly journals Cortical bone dynamics, strength, and densitometry after induction of emphysema in hamsters

2003 ◽  
Vol 95 (2) ◽  
pp. 631-634 ◽  
Author(s):  
Jill E. Shea ◽  
Scott C. Miller ◽  
David C. Poole ◽  
John P. Mattson
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Bone Formation ◽  
Cortical Bone ◽  
Pulmonary Disease ◽  
Bone Mineral ◽  
Bone Structure ◽  
Chronic Obstructive ◽  
Pathophysiological Mechanism ◽  
Mineral Density ◽  
Obstructive Pulmonary Disease

Recent evidence suggests that patients suffering from chronic obstructive pulmonary disease are also at an increased risk of developing osteoporosis. The pathophysiological mechanism(s) linking these progressive diseases is unknown. The goal of this investigation was to determine whether there were alterations in bone mineral density and content, cortical bone structure and strength, and indexes of bone formation and resorption in the elastase-induced emphysematous hamster. At 3 wk after induction of emphysema, the femoral bone mineral content was 8% less ( P = 0.026) and the femoral fracture strength was 6% less ( P = 0.032) in the emphysematous hamster than in controls. The cortical area was 8.4% less ( P = 0.013) and the periosteal mineral appositional rate was 27% less ( P = 0.05) than in controls. Additionally, the endocortical eroded surface in the emphysematous group was about twice that in the control group ( P = 0.003). Differences in some indexes of bone formation and resorption, paralleled by differences in bone structure and strength, were observed 3 wk after induction of emphysema. These differences in skeletal metabolism and strength may help explain some of the skeletal changes associated with chronic obstructive pulmonary disease in humans.

A Modification of the Unilateral Type I External Skeletal Fixator Configuration for Primary or Secondary Support of Supracondylar Humeral and Femoral Fractures

1990 ◽  
Vol 03 (04) ◽  
pp. 130-134 ◽  
Author(s):  
P. D. Schwarz ◽  
E. L. Egger ◽  
D. L. Piermattei ◽  
S. E. Klause
Keyword(s):  
Cortical Bone ◽  
Bone Structure ◽  
Femoral Fractures ◽  
Humeral Fractures ◽  
Type I ◽  
Supracondylar Fractures ◽  
Application Technique ◽  
Secondary Support ◽  
Clinical Cases

SummaryA modification of the unilateral Type I external skeletal fixator was developed for use in repair of supracondylar femoral and humeral fractures. The application technique and the results of its use in five clinical cases are discussed. In comminuted supracondylar fractures with loss of cortical bone structure, the modified unilateral Type I external skeletal fixator appears to have advantages over other external skeletal fixator configurations and bone plating.A modification of the unilateral Type I external skeletal fixator (ESF) was developed for use in repair of supracondylar femoral and humeral fractures. In comminuted supracondylar fractures with loss of cortical bone structure, the modified Type IESF appears to have advantages over other ESF configurations and bone plating.

Compressive Properties of Open Cell Aluminum Foams

2005 ◽  
Vol 486-487 ◽  
pp. 472-475 ◽  
Author(s):  
Bo Young Hur ◽  
Bu Keoun Park ◽  
Sang Youl Kim ◽  
Hoon Bae
Keyword(s):  
Aluminum Alloy ◽  
Strain Curve ◽  
Elastic Response ◽  
Aluminum Foams ◽  
Plateau Region ◽  
Lower Yield Stress ◽  
Open Cell ◽  
Linear Elastic ◽  
Open Cell Foam ◽  
Uniaxial Compressive Test

The uniaxial compressive test results of several aluminum foams are compared with aluminum alloy and ppi (pore per inch) of open cell foam. The compressive stress-strain curve of aluminum alloy foams exhibits universal three deformation regions: an initial linear elastic response, and then extended plateau region with a nearly constant flow stress, a final densification as collapsed cells are compacted together. The lower the foam densities are, the longer the plateau region is, but lower densities also imply lower yield stress.

Synchrotron microtomography to evaluate effects of different polychemotherapy drugs on cortical bone structure

2017 ◽  
Vol 93 (7) ◽  
pp. 726-733
Author(s):  
Liebert P. Nogueira ◽  
Rita Alessio ◽  
Andrea Mantuano ◽  
Gabriela Sena ◽  
Carlos E. de Almeida ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Bone Structure ◽  
Synchrotron Microtomography

Bending of lightweight circular tubes

2017 ◽  
Vol 232 (7) ◽  
pp. 1165-1178 ◽  
Author(s):  
G Mastinu ◽  
G Previati ◽  
M Gobbi
Keyword(s):  
Lightweight Design ◽  
Analytical Form ◽  
Upper And Lower Bounds ◽  
Concept Design ◽  
Optimal Solutions ◽  
Lightweight Construction ◽  
Linear Elastic ◽  
Design Variables ◽  
Maximum Stiffness ◽  
Linear Elastic Theory

The concept design (sizing) of thin-walled tubes subject to bending is dealt by resorting to rigorous design principles pertaining to engineering science. Multi-objective optimization is the proper theory that has been exploited. Minimum mass and maximum stiffness (minimum compliance) are the optimization objectives. Safety (admissible stress), stability (buckling), available room (external radius of the tube), and thickness of the tube (arising from technological issues) are introduced as constraints. Linear elastic theory is used. Optimal solutions are given in analytical form for a prompt use by designers. Such optimal solutions refer both to the objectives (mass and compliance) and to the design variables (radius and thickness of the tube). The best attainable lightweight design is discussed as a function of the constraints. In particular, given the upper and lower bounds for radius and thickness respectively, three candidate optimal solutions are addressed in the paper for concept design purposes. The comparative lightweight design of tubes made from different materials is presented. Contrary with respect to the reputation of aluminum for effective lightweight construction, steel can be the best choice, when the available room has to be saturated.

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