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Zhigang Suo's picture

A state of stress is a linear map

A state of stress in a body.  Components of stress.  Subject to a load, a body develops internal forces.  The distribution of the internal forces in the body is usually inhomogeneous. For example, when a rod is bent, part of the rod is in tension, and the other part of the rod is in compression.

If the internal forces are uniformly distributed in the body, the body is said to be in a homogeneous state of stress.  For brevity, we often say a state of stress, or just stress.

Lihua Jin's picture

Bifurcation Diagrams for the Formation of Wrinkles or Creases in Soft Bilayers

Subject to compression, elastic materials may undergo bifurcation of various kinds. A homogeneous material forms creases, whereas a bilayer consisting of a stiff film and a compliant substrate forms wrinkles. Here, we show several new types of bifurcation behavior for bilayers consisting of films and substrates of comparable elastic moduli. Depending on the ratios of moduli and thicknesses of the two materials, the critical strain for the onset of creases can be either smaller or larger than that for the onset of wrinkles.

Jianliang Xiao's picture

Professor John Rogers elected to NAS

Professor John Rogers, Swanlund Chair Professor of Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, was recently elected to the National Academy of Sciences. Congratulations to John!

Here is the link to the NAS press release: http://www.nasonline.org/news-and-multimedia/news/april-28-2015-NAS-Election.html

eskandarzade's picture

Element delatation for Severe Plastic Deformation (SPD) process

Dear all,

I am using Abaqus/explicite. My material definition is elasto plastic with stress strain values up to strain of 15!. After borthering tries now I think if I can set "Shear Failure Criteria Element Deletation option", it is possible to avoid this error. But I cannot find this option. Could someone guide me what exactly should I do in order to add distorted element deletation option and how? (an step-by-step tutorial will be approciate)

More Explanation about process:

Fabrice Pierron's picture

Academic-track fellowships available at the University of Southampton

Up to 10 New Frontiers Fellowships, which provide structured post-doctoral career development pathways to permanent academic positions, are to be appointed in the Faculty of Engineering and the Environment, University of Southampton. Applications are invited from individuals who would strengthen any of our research themes, including Structures and Solid Mechanics, Computational Engineering, Materials and Surface Engineering, Acoustics, Geomechanics and Bioengineering.

mahditaiebat's picture

Doctoral Student Positions in Computational Geomechanics at UBC

Two doctoral student positions are available in the Theoretical and Applied Geomechanics group of the Civil Engineering Department at the University of British Columbia (UBC), Vancouver, Canada. The successful candidates will work on various topics related to theoretical, computational, and applied geomechanics, including advanced constitutive modeling, scientific programming, and applications particularly in the area of geotechnical earthquake engineering.  A recent Master’s degree in soil mechanics or a related field is required.

Amorphous intergranular films as toughening structural features

The ability of amorphous intergranular films to mitigate damage formation at grain boundaries is studied with molecular dynamics simulations. We find that such films can alter both crack nucleation and crack growth rates by efficiently absorbing dislocations, with thicker films being more effective sinks.

marco.paggi's picture

PhD call in Computer Science and Systems Engineering - Specialization in Computational Mechanics

The call for new PhD positions at the IMT Institute for Advanced Studies Lucca, Italy, is open:

http://www.imtlucca.it/phd/prospective/admission

with deadline for online applications the 29th of June 2015.

A description of the Curriculum in Computer Science and Systems Engineering is available at:

2015 Melosh Medalist and Finalists

 

The Annual Robert J. Melosh Competition for the Best Student Paper in Finite Element Analysis was held last Friday, April 24, on the campus of Duke University.  

The winner of the 2015 Melosh Medal is Maurizio Chiaramonte, from Stanford University, for his paper The H-Version of the Method of Auxiliary Mapping for Higher Order Solutions of Crack Problems.”   

Maurizio was selected as the winner on the basis of both his written paper and his oral presentation.  The other finalists at the 2015 competition were:

Ashkan Vaziri's picture

Two Postdoc positions at Northeastern: Cellular structures, Soft Matter, and Biomimetic materials and structures

Two postdoctoral fellow positions at Northeastern University are available immediately, focused on the analysis of the nonlinear behavior of structures and soft matter using computational mechanics and the development and analysis of active cellular structures, and biomimetic materials. The research will be carried out at the High Performance Materials and Structures Laboratory (http://www.hpmsl.neu.edu/).

Yonggang Huang's picture

JAM now publishes a new type of paper: A Perspective

JAM now publishes a new type of paper -- A Perspective.  As invited by the Editor of JAM, the authors write a short (2~3 published pages) perspective paper on an emerging field, or an important new discovery, in mechanics.  The inaugural perspective paper, "Toughening Graphene With Topological Defects: A Perspective" by Dr. Teng Zhang and Prof. Huajian Gao from Brown University, was published in the May issue, 2015.  The PDF of the paper is attached. 

ACM2015 : International Conference on Advances in Applied and Computational Mechanics ,5-7 August 2015, Izmir/Turkey

We are proud to announce International Conference on Advances in Applied and Computational Mechanics, which is organized in the honor of  70th birthday of Prof.J.N.Reddy. This is a tribute for his many and lasting contribution to education and research in applied mechanics.

 

Conference will be held at  Izmir Tepekule Kongre Merkezi,Izmir/Turkey during August 5-7, 2015. 

Postdoc/PhD Position available 05/15/2015

We are currently accepting candidates for 1 Ph.D. and 1 Postdoc position in the Mechanical Engineering Department at the State University of New York, Stony Brook, working on the smart materials with application to sensing, energy harvesting and control.

 

Individuals with very good knowledge in the following area(s) are invited to respond.

o                     Structural Dynamics

Postdoc Position

Arttu Polojärvi's picture

PhD Position in Computational Ice Mechanics at Aalto University, Finland

We are looking for a doctoral student to join our Arctic Marine and Ice Technology research group at the Aalto University, Department of Applied Mechanics, to study ice-structure interaction process in shallow water.  In this complex interaction process an intact ice sheet fails into discrete ice blocks, which affect further stages of the process. Realistic calculations of ice loads due to this process require modeling of the ice blocks and their pile-up process.

PhD Scholarship in Computational Mechanics, Swansea UK

Fully-funded PhD Studentship: Homogenisation and Upscaling Modelling Technology for Simulation of Oil and Gas Exploration & Production

The studentship covers the full cost of UK/EU and international tuition fees, plus a tax free stipend of £14,562 p.a.

The deadline for applications is Monday 18th May 2015.

karelmatous's picture

Extreme Particle Shape Effect for Packs of Platonic Solids

For centuries, great minds like Kepler, Maxwell and Einstein have investigated the statistical characterization of many-body systems, and implications of small-scale structures on the macroscopic transport and mechanical properties. In this work, an accurate statistical description of heterogeneous particulate materials is computed using novel adaptive interpolation/integration scheme. This statistical information is then utilized within mathematical theories for predicting the overall thermo-mechanical behavior.

PhD position in computational mechanics at York University @Toronto/Canada

Vacancies exist for high calibre PhD student to join the Innovative Design and Engineering Analysis Laboratory at York University, Toronto, Canada starting immediately.
The position’s primary area of research will focus on multi-scale material modelling and optimization.

Requirement:
- Strong background in numerical simulations, finite element analysis, and/or computational solid mechanics
- Excellent programming skills and experience with high performance computing
- Proficiency in English, good written and verbal communication skills

Flavio Stochino's picture

CONSTITUTIVE MODELS FOR STRONGLY CURVED BEAMS IN THE FRAME OF ISOGEOMETRIC ANALYSIS

The current development of the isogeometric approach in various fields of mechanics is explained by the high-accuracy results which can be achieved at a reduced computational cost by codes based on non-uniform rational B-splines (NURBS). In the case of strongly curved beams the simple diagonal de Saint-Venant’s constitutive model can lead to significant errors as it has been reported in the classic literature. Other models such as Winkler’s have been proposed and seem more suitable for these kinds of structures.

zichen's picture

Residual Stresses and Poisson’s Effect Drive Shape Formation and Transition of Helical Structures

Strained multilayer structures are extensively investigated because of their applications in microelectromechanical/nano-elecromechanical systems. Here we employ a finite element method (FEM) to study the bending and twisting of multilayer structures subjected to misfit strains or residual stresses. This method is first validated by comparing the simulation results with analytic predictions for the bending radius of a bilayer strip with given misfit strains.

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