Viscoelastic Dissipation in Compact Bone: Implications for Stress-Induced Fluid Flow in Bone

1999 ◽  
Vol 122 (2) ◽  
pp. 166-172 ◽  
Author(s):  
Elijah Garner ◽  
Roderic Lakes ◽  
Taeyong Lee ◽  
Colby Swan ◽  
Richard Brand
Keyword(s):  
Fluid Flow ◽  
Shock Absorber ◽  
Compact Bone ◽  
Stress And Strain ◽  
Frequency Range ◽  
Human Compact Bone ◽  
Δ Phase ◽  
Tan Δ ◽  
Dry Bone ◽  
Damping Peak

Viscoelastic properties of wet and dry human compact bone were studied in torsion and in bending for both the longitudinal and transverse directions at frequencies from 5 mHz to 5 kHz in bending to more than 50 kHz in torsion. Two series of tests were done for different longitudinal and transverse specimens from a human tibia. Wet bone exhibited a larger viscoelastic damping tan δ (phase between stress and strain sinusoids) than dry bone over a broad range of frequency. All the results had in common a relative minimum in tan δ over a frequency range, 1 to 100 Hz, which is predominantly contained in normal activities. This behavior is inconsistent with an optimal “design” for bone as a shock absorber. There was no definitive damping peak in the range of frequencies explored, which could be attributed to fluid flow in the porosity of bone. [S0148-0731(00)00102-3]

scholarly journals Mechanical Properties and Bioactivity of Poly(Lactic Acid) Composites Containing Poly(Glycolic Acid) Fiber and Hydroxyapatite Particles

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 249
Author(s):  
Han-Seung Ko ◽  
Sangwoon Lee ◽  
Doyoung Lee ◽  
Jae Young Jho
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Flexural Strength ◽  
Interfacial Adhesion ◽  
Glycolic Acid ◽  
Compact Bone ◽  
Poly Lactic Acid ◽  
Coupling Reactions ◽  
The Poor ◽  
Human Compact Bone

To enhance the mechanical strength and bioactivity of poly(lactic acid) (PLA) to the level that can be used as a material for spinal implants, poly(glycolic acid) (PGA) fibers and hydroxyapatite (HA) were introduced as fillers to PLA composites. To improve the poor interface between HA and PLA, HA was grafted by PLA to form HA-g-PLA through coupling reactions, and mixed with PLA. The size of the HA particles in the PLA matrix was observed to be reduced from several micrometers to sub-micrometer by grafting PLA onto HA. The tensile and flexural strength of PLA/HA-g-PLA composites were increased compared with those of PLA/HA, apparently due to the better dispersion of HA and stronger interfacial adhesion between the HA and PLA matrix. We also examined the effects of the length and frequency of grafted PLA chains on the tensile strength of the composites. By the addition of unidirectionally aligned PGA fibers, the flexural strength of the composites was greatly improved to a level comparable with human compact bone. In the bioactivity tests, the growth of apatite on the surface was fastest and most uniform in the PLA/PGA fiber/HA-g-PLA composite.

Characterization of Porosity and Pore Size Distribution Changes in Human Compact Bone by Low-Field NMR

2000 ◽  
Author(s):  
Qingwen Ni ◽  
J. Derwin King ◽  
Xiaodu Wang
Keyword(s):  
Mechanical Strength ◽  
Compact Bone ◽  
Biomechanical Properties ◽  
Spongy Bone ◽  
Comprehensive Review ◽  
Low Field ◽  
Human Compact Bone ◽  
Direct Sensing ◽  
Low Field Nmr

Abstract Previous studies have shown that the overall porosity of bone has a significant effect on the mechanical strength of bone. In a comprehensive review on porosity of bone, Martin [1] described that small changes in porosity would lead to significant changes in the stiffness and strength of both compact and spongy bone. In a recently study, McCalden [2], reported that the porosity of bone has a significant effect to absorb energy during fracture. Since changes in numbers and sizes of these natural cavities are directly related to the remodeling processes and biomechanical properties of bone, a direct sensing technique to detect such changes in bone has been long wanted.

Oscillatory Compressional Behavior of Articular Cartilage and Its Associated Electromechanical Properties

1981 ◽  
Vol 103 (4) ◽  
pp. 280-292 ◽  
Author(s):  
R. C. Lee ◽  
E. H. Frank ◽  
A. J. Grodzinsky ◽  
D. K. Roylance
Keyword(s):  
Fluid Flow ◽  
Articular Cartilage ◽  
Molecular Mechanisms ◽  
Fluid Velocity ◽  
Streaming Potential ◽  
Usual Sense ◽  
Frequency Range ◽  
Confined Compression ◽  
Streaming Potentials ◽  
Compressive Stiffness

The compressive stiffness of articular cartilage was examined in oscillatory confined compression over a wide frequency range including high frequencies relevant to impact loading. Nonlinear behavior was found when the imposed sinusoidal compression amplitude exceeded a threshold value that depended on frequency. Linear behavior was attained only by suitable control of the compression amplitude. This was enabled by real time Fourier analysis of data which provided an accurate assessment of the extent of nonlinearity. For linear viscoelastic behavior, a stiffness could be defined in the usual sense. The dependence of the stiffness on ionic strength and proteoglycan content showed that electrostatic forces between matrix charge groups contribute significantly to cartilage’s compressive stiffness over the 0.001 to 20 Hz frequency range. Sinusoidal streaming potentials were also generated by oscillatory compression. A theory relating the streaming potential field to the fluid velocity field is derived and used to interpret the data. The observed magnitude of the streaming potential suggests that interstitial fluid flow is significant to cartilage behavior over the entire frequency range. The use of simultaneous streaming potential and stiffness data with an appropriate theory appears to be an important tool for assessing the relative contribution of fluid flow, intrinsic matrix viscoelasticity, or other molecular mechanisms to energy dissipation in cartilage. This method is applicable in general to hydrated, charged polymers.

scholarly journals Sugar Concentration Measurement System Using Radiofrequency Sensor

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2354
Author(s):  
Gerardo Aguila Rodriguez ◽  
Nayda Patricia Arias Duque ◽  
Blanca Estela Gonzalez Sanchez ◽  
Oscar Osvaldo Sandoval Gonzalez ◽  
Oscar Hernan Giraldo Osorio ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Measurement System ◽  
Ac Conductivity ◽  
Experimental Error ◽  
Sucrose Solution ◽  
Measuring System ◽  
Sugar Solution ◽  
Frequency Range ◽  
Tan Δ ◽  
Radiofrequency Sensor

A sugar solution measurement system was developed based on the dielectric properties of the sucrose molecule. An ac conductivity and tan δ study as a function of the frequency was performed to find the suitable frequency range for the measuring system. The results indicate that it is possible to obtain a better response of the sensor using the frequencies as the maxima peak in tan δ appears. Developed setup for sucrose solution was appropriate to measure in a 0.15 to 1 g/mL range with an experimental error of about 3%. The proposed system improves the measurement time over some other methods.

Nonlinear creep of human compact bone tissue upon stretching

1978 ◽  
Vol 14 (1) ◽  
pp. 82-84 ◽  
Author(s):  
A. �. Melnis ◽  
Ya. B. Laizan
Keyword(s):  
Bone Tissue ◽  
Compact Bone ◽  
Nonlinear Creep ◽  
Compact Bone Tissue ◽  
Human Compact Bone
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