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Nonlinear Size-Dependent Analysis of Elastic Tiny-Bodies

Submitted by M. Shaat on

Many researchers have studied the effect of surface energy on the
elastic behavior of nano-structural elements based on Gurtin and Murdoch surface
model. Many of them, however, assumed that the surface energy depends only on
the 2D symmetric infinitesimal surface strains and neglects the second-order
products of surface strains/displacement gradients. Moreover, there are some
researchers assumed that the surface energy is independent on infinitesimal
rotation tensor and neglected all rotation

Kinetic Energy-Based Temperature Computation in Non-Equilibrium Molecular Dynamics Simulation

Submitted by Bin Liu on

      The velocities of atoms in MD simulation are not objective quantities, which depend on the choice of the reference frame and sample size. In our previous study (node/3181), we discussed how to overcome this non-objectivity and compute the atomic stress objectively. In this blog, our newly published paper on temperature computation is attached, and the abstract is as follows.

how abaqus obtain DSTRAN by using UMAT for non-isothermal case

Submitted by chen1164 on
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Hi, all,

I recently encounted a big question regarding to the temperature dependent UMAT case. 

I used the UMAT for non-isothermal elasticity as followed. The DDSDDE calculating part is not shown here.

You can see that I output  ETHERM(K1),EELAS(K1),STRAN(K1),DSTRAN(K1) at the beginning of the code.

And this UMAT also saves ETHERM and EELAS to state variable array.

A Geometric Structure-Preserving Discretization Scheme for Incompressible Linearized Elasticity

Submitted by arash_yavari on

In this paper, we present a geometric discretization scheme for incompressible linearized elasticity. We use ideas from discrete exterior calculus (DEC) to write the action for a discretized elastic body modeled by a simplicial complex. After characterizing the configuration manifold of volume-preserving discrete deformations, we use Hamilton's principle on this configuration manifold. The discrete Euler-Lagrange equations are obtained without using Lagrange multipliers.

Building and Environment: Virtual Special Issue on CFD simulation of micro-scale pollutant dispersion in the built environment

Submitted by Laure Ballu on

The full articles selected for this Virtual Special Issue are freely available until 28 May 2013, from the Journal Homepage



Research highlights:

• Outdoor air quality is one of the major environmental problems today

• Micro-scale pollutant dispersion covers the building scale and the meteorological micro-scale

Journal Club Theme of March 2013: Interfacial Adhesion of Graphene - Measurements and Analysis

Submitted by Rui Huang on

Several recent papers have reported measurements of adhesion energy between graphene and other materials (e.g., Si/SiOx and copper) [1-3]. Like thin films, many experimental methods may be adopted to measure the interfacial properties of graphene, such as the pressurized blister test [2] and the double-cantilever beam test [3]. The challenges lie in the handling of atomically thin membranes and analysis/interpretation of the data.

A question about RPIM shapefunction

Submitted by 11hours on
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I am solving a simple solid mechanics problem by meshless method.  use RPIM to  calculate shape function.

when i calculate the derivatives of shape function, i found the derivative is not close to zero at the compute point, when the point is on the boundry of problem domain. 
 
My question is, should the derivative be zero if the node is on the boundry?