Skip to main content

research

Research cooperation wanted to develop a new type of nanoRAM

Submitted by Tienchong Chang on
Choose a channel featured in the header of iMechanica

Recently, we proposed a new concept to construct nano random access memory (nanoRAM) using carbon nanotubes. One of the most singnificant advantages of our design is that a RAM element is composed of only one single carbon nanotube. We are now looking for universities, companies and individuals who can perform experimental investigations on the electromechanical behavior of carbon nanotubes to realize this theoretical design.

Maximum-Entropy approximants Matlab routines

Submitted by Marino Arroyo on

Dear iMechanica colleagues,

I would like to announce that Matlab routines implementing the maximum-entropy approximation schemes presented in

Marino Arroyo and Michael Ortiz, “Local maximum-entropy approximation schemes: a seamless bridge between finite elements and meshfree methods”, International Journal for Numerical Methods in Engineering, 65:2167–2202 (2006).

can be downloaded from

The eXtended Finite Element Method (XFEM)

Submitted by phunguyen on
Choose a channel featured in the header of iMechanica
Free Tags

Hello,

The aim of this writting is to give a brief introduction to the eXtended Finite Element Method (XFEM) and investigation of its practical applications.

Firstly introduced in 1999 by the work of Black and Belytschko, XFEM is a local partition of unity (PUM) enriched finite element method. By local, it means that only a region near the discontinuties such as cracks, holes, material interfaces are enriched. The most important concept in this method is "enrichment" which means that the displacement approximation is enriched (incorporated) by additional problem-specific functions. For example, for crack modelling, the Heaviside function is used to enrich nodes whose support cut by the crack face whereas the near tip asymptotic functions are used to model the crack tip singularity (nodes whose support containes the tip are enriched).

Non linear cell mechanics

Submitted by Daniel Isabey on

Ex-vivo measure of stress-strain relationships in populations of living adherent cells by means of ligand-coated ferromagnetic microbeads (mean diameter: 4.5 µm) attached to the transmembrane mechanoreceptors which are linked to the cytoskeleton (CSK), reveal non linear cell mechanical behavior. However, this non linear cell mechanical behaviour is subjected to controversy for various reasons. First, it has not been systematically found. Results seem to depend on the micromanipulation method used and/or the cell type.

tension of cu film on Pi substrate

Submitted by Zaiwang Huang on
Choose a channel featured in the header of iMechanica

Dear professor suo I am a master graduate of professor sun jun in xi'an jiaotong university, I have done some research on the tension of cu film on Pi substrate. I have a question about the mechanical behavior of thin film:the range of elastic deformation is enlarged just as the plastic stage in your simulation results, since the mutiple neckings result in improved plasticity of Pi-bonded Cu film.could you give me some advice? many thanks

Effect of surface energy on the yield strength of nanoporous materials

Submitted by Weixu Zhang on

This is a very rough manuscript but including the original material we used. Any criticism or suggestion is welcome. The only aim of this letter is to reflect the multi-effect of surface energy on material or structure in nanosize scale. Here we report the effect of surface energy on the yield strength of nanoporous materials. The conventional micromechanics method is extended to consider the surface effect and expression of effective yield surface of nanoporous materials in complex stress state is derived.

TWELVE STEPS TO A WINNING RESEARCH PROPOSAL

Submitted by Nanshu Lu on

By George A. Hazelrigg, National Science Foundation

I have been an NSF program director for 18 years. During this time, I have personally administered the review of some 3,000 proposals and been involved in the review of perhaps another 10,000. Through this experience, I have come to see that often there are real differences between winning proposals and losing proposals. The differences are clear. Largely, they are not subjective differences or differences of quality; to a large extent, losing proposals are just plain missing elements that are found in winning proposals. Although I have known this for some time, a recent experience reinforced it.