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Haimin Yao's picture

Research Scientist Positions (in Singapore)

  • The Institute of High
    Performance Computing (IHPC), a member of the Agency for Science,
    Technology and Research (A*STAR) in Singapore, invites applications for
    eight available positions for research scientists in the field of
    theoretical and computational mechanics and materials science. These
    positions are in conjunction with the A*STAR-sponsored Visiting

Jie Wang's picture

Influence of depolarization field on polarization states in epitaxial ferroelectric thin films with biaxial misfit strains

Depolarization field and misfit strain are two important factors that may greatly influence the properties of ferroelectric thin films. The effect of depolarization field on polarization states of single-domain ferroelectric thin films with nonequally biaxial in-plane misfit strains are studied in the present work by numerically solving three coupled Euler-Lagrange equations, which are derived from the minimization of total free energy.

Biomolecular detection by a cantilever functionalized by RNA aptamers as receptor molecules

We have recently reported the label-free detection of HCV (Hepatitis C Virus) helicase by using a resonating microcantilever whose surface is functionalized by RNA aptamers as receptor molecules. This work was accepted for publication at Biosensors & Bioelectronics.

Abstract

How to solve?

How to solve the equation analytically

∂2u/∂x2 + ∂2u/∂y2 - K u =0

 

SudhirBrahmandam's picture

OOF

I recently came across this free software - OOF2 on the nist website: http://www.ctcms.nist.gov/oof/oof2/index.html I was basically looking for analyzing the effect of microstructure on the stresses in coatings, and a friend of mine mentioned this software. Since it works only on Unix or Linux (and Mac) I have not been able to install it on my PC...Have a Mac on which i will try it out soon. Will post my experience when I start using it. In the meantime wanted to know what kind of problems others tackle using this software.

Kaushik Dayal's picture

Kinetics of phase transformations in the peridynamic formulation of continuum mechanics

Abstract 

We study the kinetics of phase transformations in solids using the peridynamic formulation of continuum mechanics. The peridynamic theory is a nonlocal formulation that does not involve spatial derivatives, and is a powerful tool to study defects such as cracks and interfaces.

ramdas chennamsetti's picture

Thin plate theory...

Hi all!

I have a small doubt in the assumptions made in thin plate theory.

We make some of the following assumptions in thin plate theory (Kirchoff's classical plate theory) (KCPT).

[1] The normal stress (out of plane=> sigma(z)) is zero. and

[2] The vertical deflection 'w' is not a function of 'z' => dw/dz = 0

Xiaodong Li's picture

Ph.D. scientists and engineers

From Dr. Mark VanLandingham 

Xuanhe Zhao's picture

A method to analyze electromechanical stability of dielectric elastomer actuators

      This letter describes a method to analyze electromechanical stability of dielectric elastomer actuators.  We write the free energy of an actuator using stretches and nominal electric displacement as generalized coordinates, and pre-stresses and voltage as control parameters.  When the Hessian of the free-energy function ceases to be positive-definite, the actuator thins down drastically, often resulting in electrical breakdown.  Our calculation shows that stability of the actuator is markedly enhanced by pre-stresses.

ramdas chennamsetti's picture

Spectral Finite Elements

Hi all!

I just strated using Spectral FE technique for wave propagation applications. I am looking for some example code (for bar/beam or any geometry). If anybody has, I request them to kindly send me.

Thanks in advance.

- R, Chennamsetti

Jie-Hua Zhao's picture

Research Position at Texas Instruments (Dallas, Texas)

 
   This is a stress modeling position in TI's research
organization Silicon Technology Development (SiTD). The opening is
immediate and the position is filling very fast. Minimum requirement:
MS degree in the following fields: Mechanical Engineering, Physics,
Materials Science or Engineering Mechanics. PhD degree is preferred. 
Please email your resume to Jie-Hua (Jeff) Zhao at jhzhao@ti.com or
Darvin Edwards at rvin@ti.com. Call Jeff at 972-995-8851 for detail.

Jinxiong Zhou's picture

Propagation of instability in dielectric elastomers

When an electric voltage is applied across the thickness of a thin layer of an dielectric elastomer, the layer reduces its thickness and expands its area. This electrically induced deformation can be rapid and large, and is potentially useful as soft actuators in diverse technologies. Recent experimental and theoretical studies have shown that, when the voltage exceeds some critical value, the homogenous deformation of the layer becomes unstable, and the layer deforms into a mixture of thin and thick regions.

BoJing Zhu's picture

Mixed-mode flaws modelling at nanoscale in cell membrane system by time-domain hypersingular integral equation method

Cell membrane system has the protein-lipid-protein sandwich type structure. The membrane nanocomposites (PLP-MNs) typically exhibit pronounced nonlinear viscoplastic response under electro-thermo-elastic coupled incremental loads conditions.

Why lionize mathematics in science/engineering?

This has reference to (only) the *last paragraph* in Prof. Harry Lewis' recent post, found at: node/1423#comment-2880.

The reason I write the present post is because I always seem to have had a view of inventing, learning, or teaching mathematics that is remarkably at odds with what Prof. Lewis' last paragraph *seems* to imply.

BoJing Zhu's picture

singular index for 3D crack(II&III mode )s in bimaterials

singular index for three-dimensiaonal mixed-mode cracks perpendicular to the bimaterilas interface 

 

Cai Wei's picture

Postdoctoral position at Stanford in materials simulations

Postdoctoral positions are available in the Micro and Nano Mechanics group led by Prof. Wei Cai in the Mechanical Engineering Department at Stanford University.  [Link]

On the Possibility of Piezoelectric Nanocomposites without using Piezoelectric Materials

In a piezoelectric material an applied uniform strain can induce an electric polarization (or vice-versa). Crystallographic considerations restrict this technologically important property to non-centrosymmetric systems. It can be shown both mathematically and physically, that a non-uniform strain can potentially break the inversion symmetry and induce polarization even in non-piezoelectric dielectrics.

Zhigang Suo's picture

Using Windows Live Writer to write offline and publish to your blogs

When you use a desktop software, such as Microsoft Word, to write an entry and then paste it to iMechanica, the format often looks bad.  Instead, you can use Windows Live Writer to write blog post offline.  Installation takes about 5 minutes.  The Live Writer has a remarkably clean interface, and is very easy to use.

August Workshop on Materials Characterization for Nanoscale Reliability

We invite you to participate in the upcoming Workshop on Materials Characterization for Nanoscale Reliability, to take place 14-16 August, 2007 at the University of Colorado in Boulder, Colorado. Details are posted at http://www.boulder.nist.gov/div853/Nanoscale_Reliability_workshop/index.htm.

UG Course on Solid Mechanics

Given below is a sequence that might properly address the question of what to teach in the first (and the only) UG couse on strength of materials or solid mechanics.

0. Note: It's a mistake to believe that the contents for such a course can be covered in a linear fashion. Apply the spiral theory of knowledge and revisit certain concepts again and again: e.g., the concepts of stress, strain, fields, BV problems, theoretical structure, etc.

1. Introduction:

Zhigang Suo's picture

Google will videotape all Harvard classes and make them universally accessible

I wish that this thought had come to me earlier, so that I could have posted it on April First.  No, I'm unaware of such a program.  Instead, Harvard faculty have just emerged from a multi-year review of curriculum, and reaffirmed the commitment to liberal education, after voting out a president not too long ago.

Frontal solver

Is there an open source frontal solver in Fortran?

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