Nonlinear and quasi-linear behavior of a curved carbon nanotube vibrating in an electric force field; an analytical approachSubmitted by Payam Soltani on Tue, 2014-03-11 14:01.
Nonlinear and quasi-linear behavior of a curved carbon nanotube vibrating in an electric force field; an analytical approach
By: Payam SOLTANI, A. Kassaei, M. M. Taherian
Molecular dynamics (MD) method is an important simulation tool, but its results are always doubtful due to its unrealistic high strain rates. In this paper, a hybrid quasi-static atomistic simulation method at finite temperature is developed, which combines the advantages of MD for thermal equilibrium and atomicscale finite element method (AFEM) for efficient equilibration. Some temperature effects are embedded in static AFEM simulation by applying the virtual and equivalent thermal disturbance forces extracted from MD. Alternatively performing MD and AFEM can quickly obtain a series of thermodynamic equilibrium configurations such that a quasistatic process is modeled.
I have a problem now:
I simulated indentation on a elastic-plastic model with a rigid
indenter, the elastic ideal plastic with von mises stress model in
ABAQUS is used. A contact pair is applied to calculate the contact between the indenter and the sample.
The problem is that the obtained the force-displacement data in the loading part, which contains the plastic deformation
is not smooth, but in the unloading part is smooth. But if a model
without plastic is used, the force-displacement data is smooth.
I have tried to use a finer mesh and finer calculation increament step, but both method don't work.
Hi, i have a simple problem.
Complex Ordered Patterns in Mechanical Instability Induced Geometrically Frustrated Triangular Cellular StructuresSubmitted by Sung Hoon Kang on Wed, 2014-03-05 19:29.
We have studied how complex ordered patterns can appear from buckling-induced geometrically frustrated triangular cellular structures.
The paper is selected as the Physical Review Letters Editors' Suggestion and highlighted in Physics Synopsis as the link below.
Earth science: Missing link in mantle dynamics
Disclinations provide the missing mechanism for deforming olivine-rich rocks in the mantle
I want to simulate loading of 2D RVE of dual phase steels, by giving individual phases properties, to get homogenised mechanical properties like yield strength, % elongation etc, using micromechanics based approach. Litterature shows people have used two kinds of boundary condition viz. Periodic boundary condition and homogenous boundary condition for this case. My doubt is two folds:
1) What is the theoretical difference between these two kinds of boundary conditions?
2) how to apply these boundary conditions in a finite element framework, along with loading?. Specifically, I am interested to know what are the boundary condition on the 4 corner nodes of RVE, and how to apply loading?
Thnks in advnce,
Can someone explain the strange physical behavior in contact problem using Lagrange method in modeling a simple 2D indentation?Submitted by minhtran.1986.vn on Wed, 2014-03-05 13:33.
I am modelling a very simple 2D contact problem between a rigid indenter and a deformable squared-shape specimen. I used a implicit function f to describe the rigid indenter.
The contact condition is: Inside the contact zone of the deformable specimen, a node n is outside of rigid indenter for f(n)>0, and inside for f(n)<0. In case f(n)=0, the contacting node lies on the surface of the rigid body.
I did a 2D beam bending problem with CST and Q4 element, respectively. CST gives better accuracy. Is it due to the shear locking effect with Q4?
I am performing FSI simulation under abaqus.
The simulation consists in a porous solid (elastic isotrope and homogeneous under Abaqus/explicit) filled by a non newtonian (viscous fluid under Abaqus/CFD). The whole is contained in a cubic shell in order to apply proper boundary condition.
The cube is pinned on one face and undergoes a compression displacement on the opposite face. I have defined an interaction condition between the solid surface and the fluid model surface so Abaqus can exchange information during Explicit and CFD simulation.
The simulation runs well until I diminish the element's size, then the simulation doesn't start and give me the following error message:
Hydrogenation-Assisted Graphene Origami and Its Application in Programmable Molecular Mass Uptake, Storage, and Release
Shuze Zhu and Teng Li, ACS Nano, published online ASAP (2014)
Faculty from Caltech, UC Berkeley , University of Michigan, Georgia Tech, Brown University, University of Calgary, University of Pennsylvania, UCLA, Johns Hopkins University, Imperial College, London, and UCSD and researchers from the Lawrence Livermore National Laboratories congregated to UCSD on January 18-19, 2014 to attend the third in a series of symposia on Multiscale Dislocation Dynamics and to honor Professor Michael Ortiz on his 60th birthday. Faculty also brought their graduate students and postdocs to engage in such a powerful intellectual activity.
Comparing experimental fracture properties and micromechanical (or global-local/multiscale) finite element simulationsSubmitted by prathyush963 on Wed, 2014-02-26 17:47.
I am interested in developing a global-local finite element model (micro/macro) to simulate flexural testing of a composite material. Flexural loading will be applied on global model (macro) and crack propagation will be simulated in the local model (micro). I want to compare stress intensity factor or any other fracture property obtained from local model (micro) with that of experimental results.
I would appreciate if anyone could suggest some references/literature in this area. Any kind of suggestions would be great!
Microplane modeling of shape memory alloy tubes under tension, torsion, and proportional tension–torsion loadingSubmitted by R.Mehrabi on Wed, 2014-02-26 15:53.
In this paper, a phenomenological constitutive
model based on microplane model is used to simulate tension, torsion and proportional tension-torsion on NiTi thin-walled tube. Validation of the
microplane model against experimental results in different loading conditions demonstrates
the capability of this approach.
This publication will benefit the numerical and experimental study on SMAs.
I am interested in using a finite element software in a supercomputer setting (i.e. bluegene, cray, etc.). Does anyone have experience running finite element solutions on massively parallel supercomputers? What solvers are most amenable to such a task?
Dear sir at present iam doing meshing in hypermesh i want to know that imeshed a component with tethedral elements iwant to know that whether i can apply the properties of solid 45 element to these tetrahedral elements
We are delighted to announce the publication of the first papers in Case Studies in Fire Safety. Case Studies in Fire Safety provides an open forum for the rapid publication of short, structured case studies in fire safety and related short communications providing an essential compendium of case studies for fire protection engineers, designers, researchers and other practitioners in the field of fire safety.
Defect engineering of 2D monatomic-layer materials
; ; ; ; ; ; in Modern Physics Letters B (2013), 27(23) http://orbilu.uni.lu/handle/10993/10209#ft
I am trying to find thife transient dynamics response of clamped clamped laminated cylindrical shell subjected to Radial impulsive load. I am getting very irregular response using Newmark Integration scheme. But, using HHT-alpha method, high frequency noise from the response gets removed, but damping is intrdoced (Numerical Damping). Although i have not introduced and damping in my model. How to overcome this problem.
I need help in this regard.