Determination of material properties of a linearly elastic peridynamic material

2021 ◽  
pp. 108128652110514
Author(s):  
Adair R Aguiar ◽  
Alan B Seitenfuss
Keyword(s):  
Linear Elasticity ◽  
Poisson Ratio ◽  
Three Dimensional ◽  
The Body ◽  
Free Energy Function ◽  
Equilibrium Solutions ◽  
Plane Shear ◽  
Linear Elastic ◽  
Classical Linear Elasticity

We investigate the properties of an isotropic linear elastic peridynamic material in the context of a three-dimensional state-based peridynamic theory, which considers both length and relative angle changes, and is based on a free energy function proposed in previous work that contains four material constants. To this end, we consider a class of equilibrium problems in mechanics to show that, in interior points of the body where deformations are smooth, the corresponding solutions in classical linear elasticity are also equilibrium solutions in peridynamics. More generally, we show that the equations of equilibrium are satisfied even when two of the four peridynamic constants are arbitrary. Pure torsion of a cylindrical shaft and pure bending of a cylindrical beam are particular cases of this class of problems and are used together with a correspondence argument proposed elsewhere to determine these two constants in terms of the elasticity constants of an isotropic material from the classical linear elasticity. One of the constants has a singularity in the Poisson ratio, which needs further investigation. Two additional experiments concerning bending of cylindrical beam by terminal load and anti-plane shear of a hollow cylinder, which do not belong to the previous class of problems, are used to validate these results.

On the Motion of an Elastic Body Rolling/Sliding on an Elastic Substrate

1995 ◽  
Vol 117 (2) ◽  
pp. 308-314 ◽  
Author(s):  
A. Spector ◽  
R. C. Batra
Keyword(s):  
Elastic Body ◽  
Frictional Force ◽  
Three Dimensional ◽  
The Body ◽  
Elastic Substrate ◽  
Linear Elastic ◽  
Linear Elastic Body ◽  
Body Rolling ◽  
Applied Forces ◽  
Two Phases

The three-dimensional evolutionary problem of rolling/sliding of a linear elastic body on a linear elastic substrate is studied. The inertial properties of the body regarded as rigid are accounted for. By employing an asymptotic analysis, it is shown that the process can be divided into two phases: transient and quasistationary. An expression for the frictional force as a function of the externally applied forces and moments, and inertial properties of the body is derived. For an ellipsoid rolling/sliding on a linear elastic substrate, numerical results for the frictional force distribution, slip/adhesion subareas, and the evolution of the slip velocity are given.

Dispersion of flexural waves in circular cylindrical shells

1972 ◽  
Vol 329 (1578) ◽  
pp. 283-297 ◽  
Keyword(s):  
Linear Elasticity ◽  
Poisson Ratio ◽  
Cylindrical Shells ◽  
Three Dimensional ◽  
Real Plane ◽  
Solid Cylinder ◽  
Flexural Waves ◽  
Circular Cylindrical Shells ◽  
The Waves ◽  
Zero Frequency

The imaginary and complex branches of the dispersion spectra corresponding to flexural waves in circular cylindrical shells of various wall thicknesses including the solid cylinder have been constructed by utilizing exact three-dimensional equations of linear elasticity. The effects of wall thickness and Poisson ratio on the cut-off frequencies have been studied. Complex branches emanate from the points of frequency extrema on the purely imaginary or purely real branches and intersect the zero frequency plane, either as purely imaginary or as complex branches. The waves associated with complex branches emerging from points on the real plane are less decaying at higher frequencies.

The Muon as a Tool for Scanning the Interior of the Human Body

1969 ◽  
Vol 08 (04) ◽  
pp. 311-319 ◽  
Author(s):  
H. Daniel
Keyword(s):  
Chemical Analysis ◽  
Human Body ◽  
Three Dimensional ◽  
Simultaneous Recording ◽  
The Body ◽  
X Rays ◽  
Medium Energy ◽  
Pass Through ◽  
Dimensional Picture

SummaryA completely new technique for scanning the interior of the human body is proposed which is based on the following principle: muons from an accelerator pass through two spark chambers and are stopped in the body. The decay electrons leave the body and pass also two spark chambers. The trajectory co-ordinates read out from the spark chambers allow the determination of the point of decay with high precision. The truly three-dimensional picture obtained in this way is truly three-dimensionally displayed on a screen. Several modifications of the basic method are described, the most important ones being the simultaneous recording of the muonic X-rays (equivalent to a chemical analysis) or of the muon precession. The necessary dose is low. The most serious disadvantage is the need of a medium-energy accelerator. Quantitative figures on resolution, efficiency, and dose are given.

scholarly journals An Update on Virtopsy- A Modern Forensic Investigation Tool

KYAMC Journal ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 48-52
Author(s):  
Mushtaq Ahmad ◽  
Md Zubaidur Rahman ◽  
Farial Naima Rahman
Keyword(s):  
Imaging System ◽  
Three Dimensional ◽  
Developed Countries ◽  
Point Of View ◽  
The Body ◽  
New Era ◽  
Autopsy Examination ◽  
Resolution Imaging ◽  
Magnetic Resonance Imaging Mri

Virtopsy is a virtual alternative to a traditional autopsy, conducted with scanning and imaging technology. In developed countries Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are now being evaluated as complementary means for determination of cause of death. This paper explores the latest development and implication of virtopsy from ethical, clinical and technical point of view. Published literature in different journals with strict inclusion and exclusion criteria were extensively reviewed through use of general and Meta search engines to elucidate the applications and implications of virtual autopsy. The modern high-resolution imaging has been used as a well described aid in the setting of post-mortem investigations. Virtopsy introduces a new era in autopsy examination. It utilizes the technological innovation of modern imaging system to obtain best results and three Dimensional (3D) images of the body in multiple plains without mutilation of the human body. Now a days virtopsy is very much acceptable procedure to the forensic society. In western worlds virtopsy is likely to replace conventional autopsies in future. We can also try to implement this modern system in our country. KYAMC Journal.2021;12(1): 48-52

Effect of Poisson’s Ratio on Three-Dimensional Stress Distribution

2008 ◽  
Vol 76 (1) ◽  
Author(s):  
Z. Abdulaliyev ◽  
S. Ataoglu
Keyword(s):  
Stress Distribution ◽  
Linear Elasticity ◽  
Poisson’S Ratio ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Experimental Methods ◽  
The Body ◽  
Poisson's Ratio ◽  
Stress Components ◽  
Simply Connected

An examination of the effect of Poisson’s ratio on stress distribution is important to interpret the results of a stress-strain analysis by using experimental methods because the material of the model frequently has a different Poisson’s ratio from that of the prototype. In linear elasticity, the effect of Poisson’s ratio on three-dimensional stress distribution is theoretically explained for simply connected bodies by using static methods in this study. It is proven that the stress components are independent from Poisson’s ratio in sections of the body where the stress components arising are in equilibrium only with surface tractions. This result is useful in interpreting three-dimensional photoelasticity and other experiments and even in guiding the design.

Three-dimensional nanoprepreg and nanostitched aramid/phenolic multiwall carbon nanotubes composites: Experimental determination of in-plane shear

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4077-4096 ◽  
Author(s):  
Kadir Bilisik ◽  
Gulhan Erdogan ◽  
Erdal Sapanci ◽  
Sila Gungor
Keyword(s):  
Carbon Nanotubes ◽  
Three Dimensional ◽  
Multiwall Carbon Nanotubes ◽  
Nano Composites ◽  
Plane Shear ◽  
Pull Out ◽  
Out Of Plane ◽  
The Matrix ◽  
Multiwall Carbon

In-plane shear of nanostitched three-dimensional para-aramid/phenolic composites were experimentally investigated. Adding the nanostitched fiber into nanoprepreg para-aramid fabric preform composites slightly improved their shear strengths. The carbon-stitched composite exhibited comparatively better performance compared to the para-aramid stitched composite probably due to well bonding between carbon fiber and phenolic resin. The stitched nano composites had mainly matrix breakages and micro shear hackles in the matrix; matrix debonding and filament pull-out in the composite interface; fibrillar peeling and stripping on the filaments due to angular deformation. This mechanism probably prohibited extensive interlaminar opening in the nanostitched composites. The result exhibited that the introducing of the nano stitched fiber where multiwall carbon nanotubes were transferred to the out-of-plane of the base structure enhanced its transverse fracture as a form of confined delamination area. Therefore, the damaged tolerance properties of the stitched nano composites were enhanced compared to the base.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

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