's picture

Charge localization instability in a highly deformable dielectric elastomer

A highly deformable capacitor made of a soft dielectric and two conformal

electrodes can switch between two states discontinuously, by a first-order transition, as the total

charge varies gradually. When the total charge is small, it spreads evenly over the area of the

capacitor, and the capacitor deforms homogeneously. When the total charge is large, it localizes in

a small region of the capacitor, and this region thins down preferentially. The capacitor will

survive the localization without electrical breakdown if the area of the electrode is small. Such a

bistable system may lead to useful devices.


Zhigang Suo's picture

Massvolume vs. Spacetime

Apples and oranges. Each element in a set is a pile containing some number of apples and some number of oranges.  Adding two piles means putting them together, resulting in a pile in the set. Multiplying a pile and a real number r means finding in the set a pile r times the amount.  We model each pile as a vector, and the set as a two-dimensional vector space over the field of real numbers.

A vector represents different objects as a single entity. A pile containing some number of apples and some number of oranges is a vector. The addition of two vectors does not require us to add apples and oranges.  Rather, in adding two piles, we add apples to apples, and oranges to oranges.  The addition of vectors generalizes the addition of numbers:  adding two vectors corresponds to adding two lists of numbers in parallel.

Robert Lipton's picture

Dynamic Brittle Fracture as a Small Horizon Limit of Peridynamics

Overview: The peridynamic formulation is a
spatially nonlocal derivative free model for simulating problems of free crack
propagation.Material points interact through short-range forces and the
formulation allows for discontinuous deformations. Here the short-range forces
are initially elastic and soften beyond a critical relative displacement. We
upscale this peridynamic model to find the macroscopic (a.k.a. small horizon)
limit. It is shown that the limiting macroscopic evolution has bounded energy
given by the bulk and surface energies of brittle fracture mechanics. The
macroscopic evolution corresponds to the simultaneous evolution
of the fracture surface and linear elastic displacement away from the crack

Pradeep Sharma's picture

Liping Liu is the recepient of the 2013 Eshelby Mechanics Award for Young Faculty

It gives me great pleasure to announce the outcome of the 2013 competition for the Eshelby Mechanics Award for Young Faculty. This award is given annually to rapidly emerging junior faculty who exemplify the creative use and development of mechanics. The intent of the award is to promote the field of mechanics, especially among young researchers. The selection committee consisted of: K. Ravi-chandar (UT Austin), Huajian Gao (Brown University), Kaushik Bhattacharya (Caltech), Roger Fosdick (Minnesota University), and Yonggang Huang (Northwestern University).

The award consists of $ 1500 cash and a commemorative plaque. The receipients are honored at the ASME Applied Mechanics Banquet.

Full time PhD scholarship at RMIT University, Australia: Mechanics of Nanocomposites

PhD scholarship is immediately available at the School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Australia. Applications are invited for two open positions in one of the following areas: (1) Mechanics of nanotubes and graphene; (2) Multiscale simulation of functionally graded or nanotubes/graphene reinforced composites; (3) Thermal buckling and post-buckling of composite structures. The research work is supported by Australian Research Council under Discovery Projects scheme.


Adrian S. J. Koh's picture

One Research Fellow (Post-Doctoral) Position open in Singapore

We are looking for a highly-motivated research
fellow to work in the area of applied mechanics and materials.

The project is on energy harvesting using soft active materials. This is a joint effort between the Institute of High Performance Computing (A*STAR), and the National
University of Singapore.  The applicant
must hold a PhD degree, prior post-doctoral experience is not required. Relevant
experience in (1) experiments and/or (2) finite element modeling and simulation
is preferred.

Stochastic modeling of damage evolution in composites under environmental ageing

Stochastic modeling of damage evolution in composites under environmental ageing

R. Rahman, A. Haque, Z. Wu

Journal of Engineering Mathematics

April 2013, Volume 79, Issue 1, pp 153-166


Paul Calvert's picture

NMT Biomechanics Why is it better to be seaweed better than to be phytoplankton?

This is an introductory post to a discussion on the advantages of multicellular organisms over single-celled eukaryotes from an energy harvesting viewpoint.  It is intended for the New Mexico Tech biomechanics class but others can play.

As engineers we should seek for a numerical measure (or some measures) that allows us to decide how close an organism is to the optimum.  Consider two cases: a seaweed in comparison to a single-cell photosynthetic eukaryote and a herbivore in comparison to a single-celled eukaryotic animal.

Comment on the possible answers, problems with the answers you previously gave or improve on the question.  You will be graded on the quality of your comments over the next two weeks.



Kai-tak Wan's picture

8 Mechanical Engineering Faculty Positions

Eight Mechanical Engineering Faculty

University Mechanical and Industrial Engineering department seeks faculty
candidates for multiple tenured or tenure-track appointments at the assistant,
associate or full professor level in the Department of Mechanical and
Industrial Engineering. Please refer to the positions listed below:

HsiaoYing Shadow Huang's picture

Call for abstracts, Topic 11-13, Nanomaterials for Energy at ASME IMECE 2014

Dear Colleagues, 

On behalf of the ASME Nanomaterials for Energy Technical Committee of the Materials Division, I cordially invite your participation in Track 11, Materials: Genetics to Structures

Topic 11-13: Nanomaterials for Energy.

ASME 2014 International Mechanical Engineering Congress & Exposition will be held in Montreal, Canada during November 14-20, 2014.

Abstract submission deadline: February 17, 2014

List of the abstract topics are as follows for 11-13 Nanomaterials for Energy:

Jie. Yin's picture

One Ph.D. position in mechanics of materials for Fall, 2014

One Ph.D. position will be available in the Applied Mechanics of Materials group of Mechanical Engineering Department at
Temple University, Philadelphia, PA, USA. The position will start in the coming Fall, 2014.
The research program will focus on mechanics of soft composite materials and structures as well as
their novel applications in micro/nano-fabrication, anti-biofilm, energy absorption/harvesting, etc. In

Michael A. McCarthy's picture

Lecturer below the bar in Aircraft Maintenance and Operations

TITLE OF POST: Lecturer below the bar in Aircraft Maintenance and

University of Limerick, Ireland

Head of Department

5 Year Tenure Track. During the term of the contract the successful applicant
will have the opportunity to apply for tenure in accordance with the
University's Policy and Procedures for Granting Multi-annual Status to
Entry-level Academic Staff)

€41,498 - €51,722 p.a.

Michael A. McCarthy's picture

Senior Lecturer in Aircraft Maintenance and Operations

TITLE OF POST: Senior Lecturer in Aircraft Maintenance and

LOCATION: University
of Limerick, Ireland

of Department

CONTRACT TYPE: Multiannual

- €88,509 p.a.

Further information for applicants and application
material is available online from:

Siva P V Nadimpalli's picture

PhD position in Experimental Solid Mechanics at the New Jersey Institute of Technology

There is an opening for a
PhD student position in Dr. Nadimpalli’s group at the New Jersey Institute of
Technology starting from Fall2014. Candidate with good academic credentials and an interest to work in experimental research projects are encouraged to apply.
Ideal candidate should have a master’s degree in mechanical/materials
science/aerospace or related field with a good background in Solid Mechanics,
Materials Science, and Experimental Methods (including but not limited to SEM,
TEM, and nanofabrication methods).

Simpleware case study - permeability of 3D printed titanium implants

We have a new case study, looking at the permeability of 3D printed titanium implants. Learn how our software helped to streamline this project. 

lbotto's picture

PhD Studentship in Soft Matter Cell Biomechanics (attendance to a Chinese University and Chinese Nationality required))

Type of studentship: China Scholarship Council
(CSC) / Queen Mary Joint PhD scholarship

Institution: Queen
Mary University of London, School of Engineering and Materials Science

Julian J. Rimoli's picture

Common questions about developing educational apps

This afternoon, I had an extremely pleasant Google hangout with Daniel Suo, and Professors Zhigang Suo and Teng Li . Our main focus was on brainstorming ideas on how to improve the user experience on iMechanica. After an hour or so our conversation drifted towards educational topics including novel ways of incorporating technology in STEM education.

Konstantin Volokh's picture

Navier-Stokes model with viscous strength

In the laminar mode interactions
among molecules generate friction between layers of water that slide with
respect to each other. This friction triggers the shear stress, which is
traditionally presumed to be linearly proportional to the velocity gradient.
The proportionality coefficient characterizes the viscosity of water. Remarkably,
the standard Navier-Stokes model surmises that materials never fail – the transition
to turbulence can only be triggered by some kinematic instability of the flow. This
premise is probably the reason why the Navier-Stokes theory fails to explain

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