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.
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
Now there are three stress components sigma(x), sigma(y) and sigma(xy). The other three stress components sigma(z), sigma(xz) and sigma(yz). This is like a plane stress.
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.
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
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 [at] ti.com or
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.
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. These extended coupled incremental loads can cause high extended incremental stresses and may induce flaws initiation, growth and finally lead to fracture or failure of nanocomposites.
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.
