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Compositional patterning in coherent and dislocated alloy nanocrystals

Variations in the distribution of the alloy components can significantly influence the electronic properties

of self-organized alloy nanocrystals. Using a combination of finite element and quadratic programming

optimization methods, we have developed an efficient numerical technique to compute the equilibrium

composition profiles in coherent and dislocated nanocrystals. We show that the variations in composition

profiles arise due to the competition between chemical mixing effects and the relaxation of composition-

dependent mismatch strain as well as strain due to dislocations. We find that the composition profiles

BoJing Zhu's picture

Comparison of intrapore velocities measured and simulated in the highly macro-porous biscayne aquifer

Using the data from 3D hybrid lattice boltzmann code under parallel environments, some interesting simulated results are obtained by using Tecplot.

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Li Han's picture

Water diffusion and fracture behavior in nano-porous low-k dielectric film stacks

Among various low-dielectric constant low-k materials under development, organosilicate glassesOSGs containing nanometer-size pores are leading candidates for use as intrametal dielectrics infuture microelectronics technologies. In this paper, we investigate the direct impact of waterdiffusion on the fracture behavior of film stacks that contain porous OSG coatings.

kaushik das's picture

Symmetry breaking, snap-through, and pull-in instabilities under dynamic loading of microelectromechanical shallow arches

Arch-shaped microelectromechanical systems (MEMS) have been used as mechanical memories, micro-relays, micro-valves, optical switches, and digital micro-mirrors. A bi-stable structure, such as an arch, is characterized by a multivalued load deflection curve.

Light Activated Polymers

Soft active materials have received increasing interests recently. Here, soft materials can broadly refer to polymers, elastomers, hydrogel gels. Active materials mean that these materials can respond to external stimuli. Examples of soft active materials include shape memory polymers, environmentally responsive hydrogels, liquid crystal elastomers, etc.

Rui Huang's picture

Effect of constraint on swelling of hydrogels and formation of surface creases

Inspired by recent works by Wei Hong , Xuanhe Zhao, Zhigang Suo, and their coworkers, we started a project on hydrogels, with particular interest in various instability patterns observed in experiments. The attachment is our first manuscript on this subject. Through this work we hope to achieve the following:

Combined EAM and Stillinger-Weber potential and Combined EAM and Tersoff Potential

We have combined the EAM and the SW and the TF potentials in one
functional form. This functional form allows the modeling of metals, covalent systems, and mixed systems (M-Si,Ge,C,SiC) very efficiently allowing the study of
large systems. The combined potential retains the properties of the original EAM, SW and TF potentials for the pure elements thus limiting the fitting only for the cross interactions. The potential iscalled as the "Angular-dependent
Embedded Atom Method".

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Failure Criteria for Fiber Analysis

Hello,

I am trying to include a failure criteria for a single yarn in a plain- weave fabric model.The yarns behave as elastic-brittle( That is there is no plastic deformation)
I have the failure stresses and strains data in both fiber and transverse directions.I have  included the following properties:

Material definition
Density
Elastic : engineering constants
Viscoelastic: Relaxation test data

Analysis of Torsion-Bending of Laminated Composite Beam by FEM using ANSYS

 Hi everyone!

i'm a researcher at the Deparment of Mechanical Engineering of University of the Philippines-Diliman. currently, i'm working on completing my thesis for my MS degree. my research area in general is in mechanics of composite materials (fiber-reinforced). my problem is that of formulating the FEM solution to the torsion-bending of laminated composite beam having orthotropic layers.

Deformation gradients and atomistic simulations

I came upon a recent paper called "Deformation gradients for continuum mechanical analysis of atomistic simulations" by Jonathan A. Zimmerman , Douglas J. Bammann,  and Huajian Gao, International Journal of Solids and Structures 46 (2009) 238–253 where the authors conclude with

User Element for Ansys

Hi,

I ask for help. I need to implement a user element for shell element in Ansys, and I ask if somebody know how to do this or can send me some example. I try to read something but I not found a good example about user element in Ansys Thanks a lot.

Simple beam simulation in Abaqus

Hi everyone,

I have modelled a simple beam using continuum elements to assess the mechanical behaviour. The results are quite good since it could predict deflection close to test data. Using ABAQUS general-purpose shell elements, the deflection is quite small compared to test results ie it appears the material has become more stiff. Can any one give me a clue?

Many thanks in advance,

Emmanuel  

 

Combined EAM and Stillinger-Weber potential and Combined EAM and Tersoff Potential

We have combined the EAM and the SW and the TF potentials in one functional form. This functional form allows the modeling of metal covalent systems (M-Si,Ge,C,SiC) very efficiently allowing the study of large systems. The potential iscalled as the "Angular-dependent Embedded Atom Method".

 

 

Tensile coupon test - simulation of tensile coupons (after necking)

I have carried out several coupon tests (rectangular coupons similar to
those of ASTM E8). Some of these tests have kind of weird behavior. The
problem arises when I simulate results with ABAQUS. It goes pretty well
until a few steps after necking. Test and ABAQUS results match exactly
until several steps before fracture. After this point, there is a
discrepancy between results and my attempts in capturing the observed
behavior was unsuccessful. (around 10% or more plastic strain).
The

Saint-Venant’s Principle and Its Proof : History and Review

In this article the history of development of Saint-Venant’s Principle is reviewed, referring to the most important events concerning the principle as the historical clue, and the important works and results are evaluated; the view-points that Toupin Theorem can not be considered as a mathematical expression of Saint-Venant’s Principle and that the general Saint-Venant’s Principle does not stand, but modified Saint-Venant’s principles can be proved true are published and explained; the mathematical approaches for eslablishing modified Saint-Venant’s principles are summarized; the significan

FRP using shell 99

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hi everyone,           i attached FRP strip and u-wraps to the concrete beam. i simulate it in ansys using shell 99 for FRP strip and uwraps. but i have a problem that the beam behaves as if the FRP does not work, and the failure load is as the same for the beam without FRP. however i merged the joints between FRP strip and uwraps and the concrete joints. i hope if somenone knows the reply, i need this reply very soon.  thank you so much for cooperation.

Scaling dynamics of seismic activity fluctuations

We study the dynamics of the seismic activity in Mexico within a framework of dynamic scaling approach to time series fluctuations, recently suggested by Balankin (Phys. Rev. E, 76 (2007) 056120).We found that the relative seismic activity and the long-sampled fluctuations of seismic activity both display a self-affine invariance within a wide range of consecutive seismic evens.

Topological crossovers in the forced folding of self-avoiding matter

We study the scaling properties of forced folding of thin materials of different geometry. The scaling relations implying the topological crossovers from the folding of three dimensional plates to the folding of two-dimensional sheets, and further to the packing of one-dimensional strings, are derived for elastic and plastic manifolds. These topological crossovers in the folding of plastic manifolds were observed in experiments with predominantly plastic aluminum strips of different geometry.

interface

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Dear friends,

 

I want to find liquid and gas interface at the edge of the cube but I do not know how to do it. I know how to solve in on surface but I an unable to solve it at edge of cube. If any of u have knowledge please give me some suggestions.

 

alok

Temperature differentials in ANSYS

Hi all,

I am modeling pavement in ANSYS. I want to apply temperature differentials of 3 degree F in/in in layers. how can i do that?

Also if anyone knows the modeling of pavement in ANSYS, can you help me more?

Thanks

Abaqus: How can I fix the center of a gear? - Please Help!!

Hi,

I´m trying to simulate the contact between two gears. Each gear has 60 triangular tooth and all of them are in contact at the same time. 
I have one external gear and one internal gear. The internal gear is driven by a torque applied at it center. 
I know that I should fix the center of the gear but I don´t know how to do it with Abaqus. Ive started to use two weeks ago.`I´ve already done the tutorials and reading the Manual!.

Please Help me!!
 

Best wishes

 
Ezequiel

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