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polymer

New Book on Polymers and Viscoelasticity

Submitted by cbrinson on
I wish to inform the imechanica community about my recent book,  Polymer Engineering Science and Viscoelasticity, Springer, 2008. THe book starts at the beginning and contains both the physics of polymers and the mathematics of viscoelasticity. It is also unique in the history of mechanics in being the (first ever?) father-daughter book. Those interested in polymer mechanics may find this a useful resource! It may be found in your library or further information can be found here

Abaqus / polymer simulation

Submitted by poucinette on
Hi all,



I'm trying to model a peel T test on a composite material composed of steel and polymer (polypropylen) on Abaqus 6.7. Between these parts, there are cohesive elements COH3D8.

I have a problem with my model and I don't understand it. You can visualize my results in attachs files.

For understand this draw, a few precisions:

The elements in white has just here to guide the materials.

In B (cf attachs files), the nodes are embedded.

In A I applied a velocity.

Thickness dependent critical strain in Cu films adherent to polymer substrate

Submitted by Rongmei niu on

For the polymer-supported metal thin films that are finding increasing applications, the critical strain to nucleate microcracks ( εc ) should be more meaningful than the generally measured rupture strain. In this paper, we develop both electrical resistance method and microcrack analyzing method to determine εc of polymer-supported Cu films simply but precisely. Significant thickness dependence has been clearly revealed for εc of the polymer-supported Cu films, i.e., thinner is the film lower is εc . This dependence is suggested to cause by the constraint effect of refining grain size on the dislocation movability.

Is Strain Gradient Elasticity Relevant for Nanotechnologies?

Submitted by ravi maranganti on

Determination of Strain Gradient Elasticity Constants for Various Metals, Semiconductors, Silica, Polymers and the (Ir) relevance for Nanotechnologies

Strain gradient elasticity is often considered to be a suitable alternative to size-independent classical elasticity to, at least partially, capture elastic size-effects at the nanoscale. In the attached pre-print, borrowing methods from statistical mechanics, we present mathematical derivations that relate the strain-gradient material constants to atomic displacement correlations in a molecular dynamics computational ensemble. Using the developed relations and numerical atomistic calculations, the dynamic strain gradient constants have been explicitly determined for some representative semiconductor, metallic, amorphous and polymeric materials. This method has the distinct advantage that amorphous materials can be tackled in a straightforward manner. For crystalline materials we also employ and compare results from both empirical and ab-initio based lattice dynamics. Apart from carrying out a systematic tabulation of the relevant material parameters for various materials, we also discuss certain subtleties of strain gradient elasticity, including: the paradox associated with the sign of the strain-gradient constants, physical reasons for low or high characteristic lengths scales associated with the strain-gradient constants, and finally the relevance (or the lack thereof) of strain-gradient elasticity for nanotechnologies.