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Rolling Moment Resistance of Particles on Surfaces

In the brief presentation attached, I am summarizing my lab's recent work in the field of adhesion and work-of-adhesion measurements, and hoping to see who else is working in the field.  Here is some intro to the topic (by no means, it is complete - maybe we can add some recent work to this list as discussions develop)

Martijn Feron's picture

Split singularities and dislocation injection in strained silicon

By Martijn Feron, Zhen Zhang and Zhigang Suo

The mobility of charge carriers in silicon can be significantly increased when silicon is subject to a field of strain.In a microelectronic device, however, the strain field may be intensified at a sharp feature, such as an edge or a corner, injecting dislocations into silicon and ultimately failing the device. The strain field at an edge is singular, and is often a linear superposition of two modes of different exponents. We characterize the relative contribution of the two modes by a mode angle, and determine the critical slip systems as the amplitude of the load increases. We calculate the critical residual stress in a thin-film stripe bonded on a silicon substrate.

Mike Ciavarella's picture

shakedown in friction --- where should we send it to?

Anders Klarbring, Jim Barber and I are preparing a paper on the subject of shakedown in elastic contact problems with Coulomb friction. In particular, we establish the (rather limited) conditions under which a frictional equivalent of Melan's theorem can be applied, and we counterprove the theorem in all other cases.There is no plasticity here - the contacting bodies are linear elastic - but the analogies between the Coulomb friction law and elastic plastic deformation make us think the plasticity community might be interested in the results.

Patrick J McCluskey's picture

An introductory paper on thermal combinatorial analysis of nano-scale materials

If you are interested in nano-calorimetry or combinatorial analysis, you might also find the following paper interesting. It was published as part of the MRS spring ‘06 meeting proceedings (http://www.mrs.org/s_mrs/sec_subscribe.asp?CID=6447&DID=175796&action=de...). This paper describes the parallel nano-differential scanning calorimeter (PnDSC), a new device for measuring the thermal properties of nano-scale material systems using a combinatorial approach.

Pradeep Sharma's picture

Why is the reported elastic modulus of carbon nanotube so scattered? “Yakobsons Paradox” and Perspective from Huang et. al.

For many mechanicians and materials scientists one of the most confounding things (in the ever increasing literature on carbon nanotubes) is the reported theoretical value of the nanotube elastic modulus. Depending upon the specific paper at hand, the reported numerical values range from 1 -6 TPa!

Henry Tan's picture

modern explosion science and engineering

This blog focuses on the behaviors of energetic materials (such as solid rocket propellants, high explosives), shock waves,  and explosions. And also on the protections, from the design of protecting materials and structures.

Lecture notes:

Henry Tan's picture

Size effect of energetic crystals in high explosives and solid propellants

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Energetic materials, such as solid propellants and high explosives, can be considered as composite materials with energetic particles embedded in polymeric binder matrix. These energetic materials display strong particle size effects. For example, large particles debond earlier than small ones in high explosives.

Zhigang Suo's picture

A field of material particles vs. a field of markers

In continuum mechanics, it is a common practice to view a body as a field of material particles, so that the continuum mechanics is phrased as an algorithm to determine the function x(X, t), where X is the name of a particle, and x is the place of the particle at time t.

MichelleLOyen's picture

New Biomechanics Journal

A new journal has been started, "Journal of the Mechanical Behavior of Biomedical Materials," to be published by Elsevier from November, 2007. From the Journal's website:

Arbitrary Lagrangian Eulerian modeling in large strain solid mechanics problems

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I am interested in Arbitrary Lagrangian Eulerian formulation in modeling large strain solid mechanics problems. Can any one recommend some good resource on this topic? Both theoretical and numerical implementation are desired. Thanks in advance.

Harold S. Park's picture

Deformation of FCC Nanowires by Twinning and Slip

We present atomistic simulations of the tensile and compressive loading of single crystal FCC nanowires with <100> and <110> orientations to study the propensity of the nanowires to deform via twinning or slip.  By studying the deformation characteristics of three FCC materials with disparate stacking fault energies (gold, copper and nickel), we find that the deformation mechanisms in

Jinxiong Zhou's picture

A subdomain collocation method based on Voronoi domain partition and reproducing kernel approximation

A subdomain collocation method based on Voronoi diagrams and reproducing kernel approximation is presented. The unkonwn field variables are approximated via reproducing kernel approximation. The body integration arising from the numerical evaluation of Galerkin weak form is converted into much cheaper contour integration along the boundary of each Voronoi cell. The Voronoi cells also provide an natural structure to perform h-adaptivity.

A short paper on T-stress of an interfacial crack in a bi-material strip

The attached file is on T-stress of an interfacial crack in a bi-material strip. The geometry of the problem is the same with that of Suo and Hutchinson (1990, IJF). Using a conservation integral technique, a formula for T-stress is derived with two numerical factors.

Interfacial Thermal Stresses in a Bi-Material Assembly with a Low-Yield-Stress Bonding Layer

An approximate predictive model is developed for the evaluation of the interfacial thermal stresses in a soldered bi-material assembly with a low-yield-stress bonding material. This material is considered linearly elastic at the strain level below the yield point and ideally plastic at the higher strains. The results of the analysis can be used for the assessment of the thermally induced stresses

On the thermomechanical coupling of shape memory alloys and shape memory alloys composites

Smart materials have received much attention in recent years, especially due to their various applications in smart structures, medical devices, actuators, space and aeronautics. Among these
materials, shape memory alloys exhibit extremely large, inelastic, recoverable strains (of the order of 10%), resulting from transformation between austenitic and martensitic phases. This
transformation may be induced by a change, either in the applied stress, the temperature, or both.

HCHan's picture

Adaptation of arteries to pressure changes

Arteries are living organs that can remodel themself in response to stress changes. Arterial remodeling is a big topic and this paper shows only a tip of the iceberg.

Harold S. Park's picture

Modeling Surface Stress Effects on Nanomaterials

We present a surface Cauchy-Born approach to modeling FCC metals with nanometer scale dimensions for which surface stresses contribute significantly to the overall mechanical response. The model is based on an extension of the traditional Cauchy-Born theory in which a surface energy term that is obtained from the underlying crystal structure and governing interatomic potential is used to augment the bulk energy.

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rupture strain of films

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