Effects of Surface Roughness and Maximum Load on the Mechanical Properties of Cancellous Bone Measured by Nanoindentation

2004 ◽  
Vol 823 ◽  
Author(s):  
Eve Donnelly ◽  
Shefford P. Baker ◽  
Adele L. Boskey ◽  
Marjolein C. H. van der Meulen
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Cancellous Bone ◽  
Material Properties ◽  
Indentation Depth ◽  
Maximum Load ◽  
Indentation Modulus ◽  
Lamellar Bone ◽  
Two Samples ◽  
Intermediate Value

AbstractNanoindentation was used to assess the mechanical properties of lamellar and interlamellar tissue in dehydrated rabbit cancellous bone. The effects of surface roughness and maximum nanoindentation load on the measured mechanical properties were examined in two samples of differing surface roughness using maximum loads ranging from 250-3000 μN. As the ratio of indentation depth to surface roughness decreased below approximately 3:1, the variability in material properties increased substantially. At low loads, the indentation modulus of the lamellar bone was approximately 20% greater than that of the interlamellar bone, while at high loads the measured properties of both layers converged to an intermediate value. Relatively shallow indentations made on smooth surfaces revealed significant differences in the properties of lamellar and interlamellar bone that are consistent with microstructural observations of lamellar bone as more mineralized than interlamellar bone.

scholarly journals Effects of surface roughness and maximum load on the mechanical properties of cancellous bone measured by nanoindentation

2006 ◽  
Vol 77A (2) ◽  
pp. 426-435 ◽  
Author(s):  
Eve Donnelly ◽  
Shefford P. Baker ◽  
Adele L. Boskey ◽  
Marjolein C.H. van der Meulen
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Cancellous Bone ◽  
Maximum Load

Collagen Content and Organization Relate to Bone Nanomechanical Properties

2005 ◽  
Vol 874 ◽  
Author(s):  
Eve Donnelly ◽  
Rebecca M. Williams ◽  
Shefford P. Baker ◽  
Marjolein C. H. van der Meulen
Keyword(s):  
Mechanical Properties ◽  
Cancellous Bone ◽  
Mineral Content ◽  
Second Harmonic ◽  
Collagen Content ◽  
Indentation Modulus ◽  
Lamellar Bone ◽  
Second Harmonic Generation Microscopy ◽  
Rich Material ◽  
Lamellar Material

AbstractCancellous bone plays an important load-bearing role in the skeleton, yet relatively little is known about the microstructure-mechanical property relationships of the tissue at the sub-10 [.proportional]m level. Cancellous tissue is characterized by a layered microstructure with variable proportions of collagen and mineral. The lamellar material is substantially stiffer than the interlamellar material at the nanomechanical level. However, the microstructural origin of the observed differences in mechanical properties of these structures has not been investigated. In this study, second harmonic generation microscopy was used to examine collagen in human vertebral cancellous bone. At the same location in the tissue, nanoindentation was used to assess the indentation modulus of lamellar and interlamellar bone. The stiff lamellae corresponded to areas of highly ordered, collagen-rich material, while the compliant interlamellar regions corresponded to areas of unoriented or collagen-poor material. The lamellar bone was approximately 30% stiffer and contained approximately 50% more oriented collagen than the interlamellar bone. These observed differences in the mechanical properties and collagen content and organization of lamellar and interlamellar tissue are consistent with previous scanning electron microscopy studies showing greater mineral and collagen content and organization in lamellar bone. Given the well-known coupling between collagen and mineral in bone tissue, the mineral distribution may mirror that of the aligned collagen. However, similar measurements of local variations in mineral content are needed to confirm this hypothesis and may provide additional insights into the tissue nanomechanical behavior.

scholarly journals Negligible Effect of Estrogen Deficiency on Development of Skeletal Changes Induced by Type 1 Diabetes in Experimental Rat Models

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Aleksandra Janas ◽  
Ewa Kruczek ◽  
Piotr Londzin ◽  
Sławomir Borymski ◽  
Zenon P. Czuba ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Resorption ◽  
Bone Mass ◽  
Cancellous Bone ◽  
Maximum Load ◽  
Estrogen Deficiency ◽  
Female Rats ◽  
Skeletal System ◽  
Tibial Metaphysis ◽  
Ovx Rats

Although postmenopausal osteoporosis often occurs concurrently with diabetes, little is known about interactions between estrogen deficiency and hyperglycemia in the skeletal system. In the present study, the effects of estrogen deficiency on the development of biochemical, microstructural, and mechanical changes induced by streptozotocin-induced diabetes mellitus (DM) in the rat skeletal system were investigated. The experiments were carried out on nonovariectomized (NOVX) and ovariectomized (OVX) control and diabetic mature female Wistar rats. Serum levels of bone turnover markers (CTX-I and osteocalcin) and 23 cytokines, bone mass and mineralization, histomorphometric parameters, and mechanical properties of cancellous and compact bone were determined. The results were subjected to two-way ANOVA and principal component analysis (PCA). Estrogen deficiency induced osteoporotic changes, with increased bone resorption and formation, and worsening of microstructure (femoral metaphyseal BV/TV decreased by 13.0%) and mechanical properties of cancellous bone (the maximum load in the proximal tibial metaphysis decreased by 34.2%). DM in both the NOVX and OVX rats decreased bone mass, increased bone resorption and decreased bone formation, and worsened cancellous bone microarchitecture (for example, the femoral metaphyseal BV/TV decreased by 17.3% and 18.1%, respectively, in relation to the NOVX controls) and strength (the maximum load in the proximal tibial metaphysis decreased by 35.4% and 48.1%, respectively, in relation to the NOVX controls). Only in the diabetic rats, profound increases in some cytokine levels were noted. In conclusion, the changes induced by DM in female rats were only slightly intensified by estrogen deficiency. Despite similar effects on bone microstructure and strength, the influence of DM on the skeletal system was based on more profound systemic homeostasis changes than those induced by estrogen deficiency.

Direct polymer additive tooling – effect of additive manufactured polymer tools on part material properties for injection moulding

2019 ◽  
Vol 25 (10) ◽  
pp. 1575-1584 ◽  
Author(s):  
Achim Kampker ◽  
Johannes Triebs ◽  
Sebastian Kawollek ◽  
Peter Ayvaz ◽  
Tom Beyer
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Mechanical Behaviour ◽  
Material Properties ◽  
Tensile Elongation ◽  
Morphological Structure ◽  
Mould Insert ◽  
Content Type ◽  
3D Print ◽  
Standard Specimens

Purpose This study aims to investigate the influence of additive manufactured polymer injection moulds on the mechanical properties of moulded parts. Therefore, polymer moulds are used to inject standard specimens to compare material properties to specimens produced using a conventional aluminium tool. Design/methodology/approach PolyJet technology is used to three-dimensional (3D)-print a mould insert in Digital ABS and selective laser sintering (SLS) technology is used to 3D-print a mould insert in polyamide (PA) 3200 GF. A conventionally aluminium milled tool serves as reference. Standard specimens are produced to compare resulting mechanical properties, shrinkage behaviour and morphology. Findings The determined material characteristics of the manufactured prototypes from the additive manufactured tools show differences in terms of mechanical behaviour to those from the aluminium reference tool. The most significant differences are an up to 25 per cent lower tensile elongation and an up to 63 per cent lower elongation at break resulting in an embrittlement of the specimens produced. These differences seem to be mainly due to the different morphological structure caused by the lower thermal conductivity and greater surface roughness of the polymer tools. Research limitations/implications The determined differences in mechanical behaviour can partly be assigned to differences in surface roughness and morphological structure of the resulting parts. The exact extend of either cause, however, cannot be clearly determined. Originality/value This study provides a comparison between the part material properties from conventionally milled aluminium tools and polymer inserts manufactured via additive tooling.

MECHANICAL PROPERTIES OF THERMAL ARC SPRAY ALUMINIUM COATING IN ATMOSPHERIC CONDITION

2015 ◽  
Vol 76 (10) ◽  
Author(s):  
Muhamad Hafiz Abd Malek ◽  
Nor Hayati Saad ◽  
Sunhaji Kiyai Abas ◽  
Noriyati Mohd Shah
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Corrosion Rate ◽  
Coating Thickness ◽  
Salt Spray ◽  
Atmospheric Condition ◽  
Spray Coating ◽  
Image Analyzer ◽  
Arc Spray ◽  
Two Samples

Thermal arc spray coating was regard as most preferred method as a protective coating due to its ability to sustain in high temperature, high friction surface, and low cost process. It has been applied by most of industrialist especially in oil and gas field, where current application of the coating used in onshore. This research is a study on mechanical properties of thermal arc spray coating by using aluminium alloy with purity 99.5% as coating material. Two samples with different coating thickness at range of 200 μm – 300 μm and 300 μm – 400 μm were used for this research. Some of tests were prepared to evaluate coating mechanical properties. Surface microstructures were viewed and analysed using scanning electron microscope and energy dispersive x-ray analysis.  The hardness was inspected using Vickers Hardness testing. Corrosion rate was established by performing Salt Spray Test. Porosity value was calculated using Image Analyzer. Surface roughness was viewed using Infinitefocus G4 machine. Experimental results were found that coating porosity was raising with enhancing of coating thickness. The increment coating thickness also resulted in reduction of hardness and surface roughness. For corrosion rate purpose, two samples with coating thickness at range of 200 μm – 300 μm and two samples with coating thickness at range 300 μm – 400 μm were prepared. It recorded at Rating 5 – Rating 7 after exposed in salt spray cabinet within 144 hours. As a result, coating thickness at range of 200 μm – 300 μm performs the most efficiency in terms of mechanical properties; less corrosion rate, less porosity and contribute to high hardness and surface roughness.  

scholarly journals Changes in Roughness and Mechanical Properties of Invisalign® Appliances after One- and Two-Weeks Use

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2406 ◽  
Author(s):  
Alexandra K. Papadopoulou ◽  
Aurelie Cantele ◽  
Georgios Polychronis ◽  
Spiros Zinelis ◽  
Theodore Eliades
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Detrimental Effect ◽  
Internal Surface ◽  
Acrylic Resin ◽  
Indentation Modulus ◽  
Instrumented Indentation ◽  
Post Hoc ◽  
Relaxation Index ◽  
Martens Hardness

The aim of this study was to estimate the possible changes of surface roughness and the mechanical properties of Invisalign® appliances over one- and two-week of service. Forty appliances with attachments were retrieved after the end of orthodontic treatment from different patients. Half of them had been used for one week (1W), and the rest for two weeks (2W). Ten unused Invisalign® appliances were used as the control (CON). An equal number of teeth possessing attachments were cut of aligners deriving from all groups (1W, 2W, and CON), and the Sa, Sq, Sz, Sc, and Sv roughness parameters of the internal surface of the aligner attachment area and the opposite lingual side (which was in contact to enamel) were determined by optical profilometry. Then, ten first molars originating from all groups were embedded in acrylic resin, and were ground and polished. Instrumented indentation testing (IIT) was performed in order to determine the Martens hardness (HM), indentation modulus (EIT), and relaxation index (RIT), according to ISO 14577-2002. The produced data were statistically processed by one- or two-way analysis of variance (ANOVA) and multiple comparison post-hoc tests (a = 0.05). Both the surface roughness and mechanical properties of the retrieved groups (1W and 2W) showed statistically significant differences compared with CON, but without statistically significant differences between each other. The roughness variables of the as-received material were shown to be reduced after intraoral service demonstrating a wear effect. Ageing has a detrimental effect on the surface roughness and mechanical properties of Invisalign® appliances, although this effect is restricted to the first week of clinical usage.

scholarly journals Transversely Isotropic Elasticity Imaging of Cancellous Bone

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Spencer W. Shore ◽  
Paul E. Barbone ◽  
Assad A. Oberai ◽  
Elise F. Morgan
Keyword(s):  
Mechanical Properties ◽  
Inverse Problem ◽  
Cancellous Bone ◽  
Material Properties ◽  
Transversely Isotropic ◽  
Elasticity Imaging ◽  
Elastic Parameters ◽  
Displacement Fields ◽  
Isotropic Materials ◽  
Isotropic Elasticity

To measure spatial variations in mechanical properties of biological materials, prior studies have typically performed mechanical tests on excised specimens of tissue. Less invasive measurements, however, are preferable in many applications, such as patient-specific modeling, disease diagnosis, and tracking of age- or damage-related degradation of mechanical properties. Elasticity imaging (elastography) is a nondestructive imaging method in which the distribution of elastic properties throughout a specimen can be reconstructed from measured strain or displacement fields. To date, most work in elasticity imaging has concerned incompressible, isotropic materials. This study presents an extension of elasticity imaging to three-dimensional, compressible, transversely isotropic materials. The formulation and solution of an inverse problem for an anisotropic tissue subjected to a combination of quasi-static loads is described, and an optimization and regularization strategy that indirectly obtains the solution to the inverse problem is presented. Several applications of transversely isotropic elasticity imaging to cancellous bone from the human vertebra are then considered. The feasibility of using isotropic elasticity imaging to obtain meaningful reconstructions of the distribution of material properties for vertebral cancellous bone from experiment is established. However, using simulation, it is shown that an isotropic reconstruction is not appropriate for anisotropic materials. It is further shown that the transversely isotropic method identifies a solution that predicts the measured displacements, reveals regions of low stiffness, and recovers all five elastic parameters with approximately 10% error. The recovery of a given elastic parameter is found to require the presence of its corresponding strain (e.g., a deformation that generates ɛ12 is necessary to reconstruct C1212), and the application of regularization is shown to improve accuracy. Finally, the effects of noise on reconstruction quality is demonstrated and a signal-to-noise ratio (SNR) of 40dB is identified as a reasonable threshold for obtaining accurate reconstructions from experimental data. This study demonstrates that given an appropriate set of displacement fields, level of regularization, and signal strength, the transversely isotropic method can recover the relative magnitudes of all five elastic parameters without an independent measurement of stress. The quality of the reconstructions improves with increasing contrast, magnitude of deformation, and asymmetry in the distributions of material properties, indicating that elasticity imaging of cancellous bone could be a useful tool in laboratory studies to monitor the progression of damage and disease in this tissue.

Mapping the Mechanical Properties of Cancellous Bone from the Femoral Head

2015 ◽  
Vol 801 ◽  
pp. 273-277
Author(s):  
Karla Noemy Kun ◽  
Lorand Kun ◽  
Ramona Nagy ◽  
Karoly Menyhardt ◽  
Dana Silaghi-Perju ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Head ◽  
Cancellous Bone ◽  
Material Properties ◽  
Compression Testing ◽  
Experimental Program ◽  
Element Analysis

This work presents an experimental program to determine the mechanical properties of cancellous bone in the femoral head as a function of location. To achieve this several specimens of cancellous bone of approximately 10 mm height and 10 mm diameter were obtained from one human femoral head, starting the sampling from its main loading compressive direction. All specimens underwent compression testing in order to determine the mechanical properties of each specimen and thus a properties map of the cancellous bone in the femoral head was obtained. Based on the results a parametric file with material properties was created in order to be used by professionals in finite element analysis programs.

scholarly journals A Study on Material Properties of Intermetallic Phases in a Multicomponent Hypereutectic Al-Si Alloy with the Use of Nanoindentation Testing

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5612
Author(s):  
Mirosław Tupaj ◽  
Antoni Władysław Orłowicz ◽  
Marek Mróz ◽  
Andrzej Trytek ◽  
Anna Janina Dolata ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Material Properties ◽  
Maximum Load ◽  
Intermetallic Phases ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Alloy Matrix ◽  
X Ray ◽  
Aluminum Silicon Alloy ◽  
The Matrix

The paper concerns modeling the microstructure of a hypereutectic aluminum-silicon alloy developed by the authors with the purpose of application for automobile cylinder liners showing high resistance to abrasive wear at least equal to that of cast-iron liners. With the use of the nanoindentation method, material properties of intermetallic phases and matrix in a hypereutectic Al-Si alloy containing Mn, Cu, Cr, Ni, V, Fe, and Mg as additives were examined. The scanning electron microscope equipped with an adapter for chemical composition microanalysis was used to determine the chemical composition of intermetallics and of the alloy matrix. Intermetallic phases, such as Al(Fe,Mn,M)Si, Al(Cr,V,M)Si, AlFeSi, AlFeNiM, AlCuNi, Al2Cu, and Mg2Si, including those supersaturated with various alloying elements (M), were identified based on results of X-ray diffraction (XRD) tests and microanalysis of chemical composition carried out with the use of X-ray energy dispersive spectroscopy (EDS). Shapes of the phases included regular, irregular, or elongated polygons. On the disclosed intermetallic phases, silicon precipitations, the matrix, values of the indentation hardness (HIT), and the indentation modulus (EIT) were determined by performing nanoindentation tests with the use of a Nanoindentation Tester NHT (CSM Instruments) equipped with a Berkovich B-L 32 diamond indenter. The adopted maximum load value was 20 mN.

Nanoindentation Measurements of Mechanical Properties of Polystyrene Thin Films

2000 ◽  
Vol 649 ◽  
Author(s):  
Min Li ◽  
C. Barry Carter ◽  
William W. Gerberich
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Room Temperature ◽  
Maximum Load ◽  
Adhesion Energy ◽  
Work Of Adhesion ◽  
Stiffness Analysis ◽  
Molecular Weights ◽  
Significant Difference ◽  
Unloading Stiffness

ABSTRACTThe elastic modulus and work of adhesion of thin polystyrene (PS) films have been evaluated from nanoindentation load-displacement curves. The modulus was calculated using two methods: an unloading stiffness analysis and an elastoplastic unloading analysis. Results indicate that the latter analysis gives better modulus evaluation for the polymers. Two methods were also utilized in determining the work of adhesion, one using the pull-off forces and one using the displacement difference at zero force and pull-off force. The values given by the two methods are close. The effects of surface roughness and maximum load on the adhesion measurements are discussed. Different molecular weights were also chosen to compare the characteristics of the polymers during use under the same conditions. No significant difference in either modulus or adhesion energy was shown between the PSs of very low, moderate, and high molecular weights at room temperature.

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