Biaxial Failure Behavior of Bovine Tibial Trabecular Bone

2002 ◽  
Vol 124 (6) ◽  
pp. 699-705 ◽  
Author(s):  
Glen L. Niebur ◽  
Michael J. Feldstein ◽  
Tony M. Keaveny
Keyword(s):  
Trabecular Bone ◽  
Volume Fraction ◽  
Yield Criterion ◽  
Failure Mechanisms ◽  
Tissue Level ◽  
Failure Behavior ◽  
Transverse Loading ◽  
Wide Range ◽  
Plain Strain ◽  
Apparent Level

Multiaxial failure properties of trabecular bone are important for modeling of whole bone fracture and can provide insight into structure-function relationships. There is currently no consensus on the most appropriate form of multiaxial yield criterion for trabecular bone. Using experimentally validated, high-resolution, non-linear finite element models, biaxial plain strain boundary conditions were applied to seven bovine tibial specimens. The dependence of multiaxial yield properties on volume fraction was investigated to quantify the interspecimen heterogeneity in yield stresses and strains. Two specimens were further analyzed to determine the yield properties for a wide range of biaxial strain loading conditions. The locations and quantities of tissue level yielding were compared for on-axis, transverse, and biaxial apparent level yielding to elucidate the micromechanical failure mechanisms. As reported for uniaxial loading of trabecular bone, the yield strains in multiaxial loading did not depend on volume fraction, whereas the yield stresses did. Micromechanical analysis indicated that the failure mechanisms in the on-axis and transverse loading directions were mostly independent. Consistent with this, the biaxial yield properties were best described by independent curves for on-axis and transverse loading. These findings establish that the multiaxial failure of trabecular bone is predominantly governed by the strain along the loading direction, requiring separate analytical expressions for each orthotropic axis to capture the apparent level yield behavior.

Influence of bone volume fraction and architecture on computed large-deformation failure mechanisms in human trabecular bone

Bone ◽  
2006 ◽  
Vol 39 (6) ◽  
pp. 1218-1225 ◽  
Author(s):  
Grant Bevill ◽  
Senthil K. Eswaran ◽  
Atul Gupta ◽  
Panayiotis Papadopoulos ◽  
Tony M. Keaveny
Keyword(s):  
Trabecular Bone ◽  
Large Deformation ◽  
Volume Fraction ◽  
Failure Mechanisms ◽  
Bone Volume ◽  
Bone Volume Fraction ◽  
Human Trabecular Bone

scholarly journals The Quartic Piecewise-Linear Criterion for the Multiaxial Yield Behavior of Human Trabecular Bone

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Arnav Sanyal ◽  
Joanna Scheffelin ◽  
Tony M. Keaveny
Keyword(s):  
Finite Element ◽  
Trabecular Bone ◽  
Volume Fraction ◽  
Yield Criterion ◽  
Shear Loading ◽  
Bone Volume ◽  
Mechanical Anisotropy ◽  
Bone Volume Fraction ◽  
Human Trabecular Bone ◽  
Strain Space

Prior multiaxial strength studies on trabecular bone have either not addressed large variations in bone volume fraction and microarchitecture, or have not addressed the full range of multiaxial stress states. Addressing these limitations, we utilized micro-computed tomography (μCT) based nonlinear finite element analysis to investigate the complete 3D multiaxial failure behavior of ten specimens (5 mm cube) of human trabecular bone, taken from three anatomic sites and spanning a wide range of bone volume fraction (0.09–0.36), mechanical anisotropy (range of E3/E1 = 3.0–12.0), and microarchitecture. We found that most of the observed variation in multiaxial strength behavior could be accounted for by normalizing the multiaxial strength by specimen-specific values of uniaxial strength (tension, compression in the longitudinal and transverse directions). Scatter between specimens was reduced further when the normalized multiaxial strength was described in strain space. The resulting multiaxial failure envelope in this normalized-strain space had a rectangular boxlike shape for normal–normal loading and either a rhomboidal boxlike shape or a triangular shape for normal-shear loading, depending on the loading direction. The finite element data were well described by a single quartic yield criterion in the 6D normalized-strain space combined with a piecewise linear yield criterion in two planes for normal-shear loading (mean error ± SD: 4.6 ± 0.8% for the finite element data versus the criterion). This multiaxial yield criterion in normalized-strain space can be used to describe the complete 3D multiaxial failure behavior of human trabecular bone across a wide range of bone volume fraction, mechanical anisotropy, and microarchitecture.

Application of the Tsai–Wu Quadratic Multiaxial Failure Criterion to Bovine Trabecular Bone

1999 ◽  
Vol 121 (1) ◽  
pp. 99-107 ◽  
Author(s):  
T. M. Keaveny ◽  
E. F. Wachtel ◽  
S. P. Zadesky ◽  
Y. P. Arramon
Keyword(s):  
Trabecular Bone ◽  
Apparent Density ◽  
Failure Criterion ◽  
Radial Pressure ◽  
Nonlinear Dependence ◽  
Triaxial Tests ◽  
Failure Behavior ◽  
Transverse Loading ◽  
Trabecular Network ◽  
Stress States

As a first step toward development of a multiaxial failure criterion for human trabecular bone, the Tsai–Wu quadratic failure criterion was modified as a function of apparent density and applied to bovine tibial trabecular bone. Previous data from uniaxial compressive, tensile, and torsion tests (n = 139 total) were combined with those from new triaxial tests (n = 17) to calibrate and then verify the criterion. Combinations of axial compression and radial pressure were used to produce the triaxial compressive stress states. All tests were performed with minimal end artifacts in the principal material coordinate system of the trabecular network. Results indicated that the stress interaction term F12 exhibited a strong nonlinear dependence on apparent density (r2 > 0.99), ranging from −0.126 MPa−2 at low densities (0.29 g/cm3) to 0.005 MPa−2 at high densities (0.63 g/cm3). After calibration and when used to predict behavior of new specimens without any curve-fitting, the Tsai–Wu criterion had a mean (± SD) error of −32.6 ± 10.6 percent. Except for the highest density triaxial specimens, most (15/17 specimens) failed at axial stresses close to their predicted uniaxial values, and some reinforcement for transverse loading was observed. We conclude that the Tsai–Wu quadratic criterion, as formulated here, is at best only a reasonable predictor of the multiaxial failure behavior of trabecular bone, and further work is required before it can be confidently applied to human bone.

A Microstructural Model for the Tensile Constitutive and Failure Behavior of Soft Skeletal Connective Tissues

1998 ◽  
Vol 120 (1) ◽  
pp. 55-61 ◽  
Author(s):  
T. A. L. Wren ◽  
D. R. Carter
Keyword(s):  
Volume Fraction ◽  
Strain Curve ◽  
Ground Substance ◽  
Uniaxial Tensile ◽  
Failure Behavior ◽  
Connective Tissues ◽  
Fiber Volume ◽  
Two Phase ◽  
Wide Range ◽  
Microstructural Model

We propose a microstructural model for the uniaxial tensile constitutive and failure behavior of soft skeletal connective tissues. The model characterizes the tissues as two-phase composites consisting of collagen fibers embedded in ground substance. Nonlinear toe region behavior in the stress versus strain curve results from the straightening of crimped fibers and from fiber reorientation. Subsequent linear behavior results from fiber stretching affected by fiber volume fraction, collagen type, crosslink density, and fiber orientation. Finally, the tissue fails when fibers successively rupture at their ultimate tensile strain. We apply the model to tendon, meniscus, and articular cartilage. The model provides a consistent approach to modeling the tensile behavior of a wide range of soft skeletal connective tissues.

scholarly journals Factors Affecting Acoustic Properties of Natural-Fiber-Based Materials and Composites: A Review

Textiles ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 55-85
Author(s):  
Tufail Hassan ◽  
Hafsa Jamshaid ◽  
Rajesh Mishra ◽  
Muhammad Qamar Khan ◽  
Michal Petru ◽  
...  
Keyword(s):  
Sound Absorption ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Type ◽  
Alkali Treatment ◽  
Acoustic Properties ◽  
Synthetic Fiber ◽  
Sound Insulation ◽  
Factors Affecting ◽  
Wide Range

Recently, very rapid growth has been observed in the innovations and use of natural-fiber-based materials and composites for acoustic applications due to their environmentally friendly nature, low cost, and good acoustic absorption capability. However, there are still challenges for researchers to improve the mechanical and acoustic properties of natural fiber composites. In contrast, synthetic fiber-based composites have good mechanical properties and can be used in a wide range of structural and automotive applications. This review aims to provide a short overview of the different factors that affect the acoustic properties of natural-fiber-based materials and composites. The various factors that influence acoustic performance are fiber type, fineness, length, orientation, density, volume fraction in the composite, thickness, level of compression, and design. The details of various factors affecting the acoustic behavior of the fiber-based composites are described. Natural-fiber-based composites exhibit relatively good sound absorption capability due to their porous structure. Surface modification by alkali treatment can enhance the sound absorption performance. These materials can be used in buildings and interiors for efficient sound insulation.

scholarly journals Bone health in spacefaring rodents and primates: systematic review and meta-analysis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jingyan Fu ◽  
Matthew Goldsmith ◽  
Sequoia D. Crooks ◽  
Sean F. Condon ◽  
Martin Morris ◽  
...  
Keyword(s):  
Bone Formation ◽  
Trabecular Bone ◽  
Bone Health ◽  
Volume Fraction ◽  
Meta Analysis ◽  
Bone Volume ◽  
Trabecular Bone Volume ◽  
Bone Volume Fraction ◽  
Percentage Difference ◽  
Induced Changes

AbstractAnimals in space exploration studies serve both as a model for human physiology and as a means to understand the physiological effects of microgravity. To quantify the microgravity-induced changes to bone health in animals, we systematically searched Medline, Embase, Web of Science, BIOSIS, and NASA Technical reports. We selected 40 papers focusing on the bone health of 95 rats, 61 mice, and 9 rhesus monkeys from 22 space missions. The percentage difference from ground control in rodents was –24.1% [Confidence interval: −43.4, −4.9] for trabecular bone volume fraction and –5.9% [−8.0, −3.8] for the cortical area. In primates, trabecular bone volume fraction was lower by –25.2% [−35.6, −14.7] in spaceflight animals compared to GC. Bone formation indices in rodent trabecular and cortical bone were significantly lower in microgravity. In contrast, osteoclast numbers were not affected in rats and were variably affected in mice. Thus, microgravity induces bone deficits in rodents and primates likely through the suppression of bone formation.

scholarly journals A Mixed Numerical-Experimental Method to Characterize Metal-Polymer Interfaces for Crash Applications

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 818
Author(s):  
Jonas Richter ◽  
Moritz Kuhtz ◽  
Andreas Hornig ◽  
Mohamed Harhash ◽  
Heinz Palkowski ◽  
...  
Keyword(s):  
Experimental Parameter ◽  
Dissimilar Materials ◽  
Calibration Method ◽  
Parameter Determination ◽  
Failure Behavior ◽  
Cohesive Elements ◽  
Interface Failure ◽  
Wide Range ◽  
Polymer Metal ◽  
Metal Polymer

Metallic (M) and polymer (P) materials as layered hybrid metal-polymer-metal (MPM) sandwiches offer a wide range of applications by combining the advantages of both material classes. The interfaces between the materials have a considerable impact on the resulting mechanical properties of the composite and its structural performance. Besides the fact that the experimental methods to determine the properties of the single constituents are well established, the characterization of interface failure behavior between dissimilar materials is very challenging. In this study, a mixed numerical–experimental approach for the determination of the mode I energy release rate is investigated. Using the example of an interface between a steel (St) and a thermoplastic polyolefin (PP/PE), the process of specimen development, experimental parameter determination, and numerical calibration is presented. A modified design of the Double Cantilever Beam (DCB) is utilized to characterize the interlaminar properties and a tailored experimental setup is presented. For this, an inverse calibration method is used by employing numerical studies using cohesive elements and the explicit solver of LS-DYNA based on the force-displacement and crack propagation results.

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