Solid State Property - Bonding Electron Density – Volume Plasmon Energy Scaling Relationships: Novel AEM Technique for In Situ Diagnostics of Material Properties at the Nanoscale

2003 ◽  
Vol 791 ◽  
Author(s):  
Vladimir P. Oleshko ◽  
James M. Howe

ABSTRACTQuantized high-frequency (∼1016 Hz) correlated longitudinal electron excitations (plasmons) generated in the energy-loss range 0–50 eV by fast electrons passing through any solid enable one to probe various states of matter. Their energy, Ep, is directly related to the density of valence electrons, thus allowing determination of solid-state properties that are governed by ground-state densities. Universal features and scaling in relations between Ep and the cohesive energy per atomic volume, bonding electron density and elastic constants have been established. The resulting correlations follow the universal binding energy relationship, thus providing new insights into the fundamental nature of structure-property relationships. They allow direct in situ determination of local material properties in an analytical electron microscope, as illustrated by examples utilizing Al- and Ti-based structural alloys.

2013 ◽  
Vol 465-466 ◽  
pp. 647-651 ◽  
Author(s):  
Saifulnizan Jamian ◽  
Mohammad Rusydi Zainal Abidin

In this paper, mechanical properties of Al functionally graded materials (FGMs) crash box fabricated by heat treatment is predicted based on temperature distribution and experimental data. The Al FGM crash box is fabricated by applying different temperature at the both ends of a square hollow Al column for 4 hours. Due to the gradient in heat treatment temperature along the height of the Al column, the microstructure is locally varied so that a certain variation of local material properties is achieved. The determination of material properties at any point along the height of Al FGM crash box experimentally is uneasy. The Lagrange interpolation method is proposed to predict the variation of local material properties at any point along the height of Al FGM crash box for further work such as simulation of impact on the crash box. The determination of mechanical properties is successfully predicted using the available experimental data and the temperature distribution obtained in simulation.


2014 ◽  
Vol 48 (11) ◽  
pp. 3571-3584 ◽  
Author(s):  
Gerhard Fink ◽  
Andrea Frangi ◽  
Jochen Kohler

2013 ◽  
Vol 586 ◽  
pp. 146-149
Author(s):  
Pavel Hutař ◽  
Martin Ševčík ◽  
Ralf Lach ◽  
Zdeněk Knésl ◽  
Luboš Náhlík ◽  
...  

The paper presents a methodology for the lifetime assessment of welded polymer pipes. A fracture mechanics analysis of a butt-welded joint is performed by simulating radial crack growth in the nonhomogenous region of the pipe weld. It was found that the presence of material nonhomogeneity in the pipe weld caused by the welding procedure leads to an increase in the stress intensity factor of the radial crack and changes the usual failure mode of the pipe system. This can lead to a significant reduction in the lifetime of the pipe system.


1998 ◽  
Vol 120 (2) ◽  
pp. 188-194 ◽  
Author(s):  
B. R. Simon ◽  
M. V. Kaufmann ◽  
M. A. McAfee ◽  
A. L. Baldwin ◽  
L. M. Wilson

A “porohyperelastic” (PHE) material model is described and the theoretical frame-work presented that allows identification of the necessary material properties functions for soft arterial tissues. A generalized Fung form is proposed for the PHE constitutive law in which the two fundamental Lagrangian material properties are the effective strain energy density function, We, and the hydraulic permeability, k˜ij. The PHE model is based on isotropic forms using We=Ue(φ)=1/2C0(eφ−1) and the radial component of permeability, k˜RR=k˜RR(φ), with φ=C′1(I¯1−3)+C′2(I¯2−3)+K′(J−1)2. The methods for determination of these material properties are illustrated using experimental data from in situ rabbit aortas. Three experiments are described to determine parameters in Ue and k˜RR for the intima and media of the aortas, i.e., (1) undrained tests to determine C0, C′1, and C′2 (2) drained tests to determine K′; and (3) steady-state pressurization tests of intact and de-endothelialized vessels to determine intimal and medial permeability (adventitia removed in these models). Data-reduction procedures are presented that allow determination of k˜RR for the intima and media and Ue for the media using experimental data. The effectiveness and accuracy of these procedures are studied using input “data” from finite element models generated with the ABAQUS program. The isotropic theory and data-reduction methods give good approximations for the PHE properties of in situ aortas. These methods can be extended to include arterial tissue remodeling and anisotropic behavior when appropriate experimental data are available.


Soft Matter ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 140-150 ◽  
Author(s):  
Christian Ganser ◽  
Caterina Czibula ◽  
Daniel Tscharnuter ◽  
Thomas Schöberl ◽  
Christian Teichert ◽  
...  

We present an atomic force microscopy based method to study viscoelastic material properties at low indentation depths with non-negligible adhesion and surface roughness.


Solar Physics ◽  
1984 ◽  
Vol 90 (2) ◽  
Author(s):  
J.-L. Bougeret ◽  
J.H. King ◽  
R. Schwenn

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