Indentation: a simple, nondestructive method for characterizing the mechanical and transport properties of pH-sensitive hydrogel
Coupled phase transformations and plasticity as a field theory of deformation incompatibility
(to appear in International Journal of Fracture; Proceedings of the 5th Intl. Symposium on Defect andMaterial Mechanics)
Amit Acharya and Claude Fressengeas
Effect of temperature on the stability of dielectric elastomers
Dielectric elastomer (DE) is a kind of electroactive polymer material,
capable of large deformation up to 380%. However, under conservative
operating conditions, DE is susceptible to instability with a small
deformation due to various modes of failure, including electrical
breakdown, electromechanical instability (EMI), loss of tension and
rupture by stretch. This paper proposes a free energy model in the
thermodynamic system of DE involving thermoelastic strain energy,
electric energy and purely thermal contribution energy to obtain the
stability conditions of all failure modes. The numerical results
indicate that the increase in temperature can markedly contribute to
improving the entropy production, the actuation stress and the critical
Time-averaged coarse variables for multiscale dynamics
(to appear in Quarterly of Applied Mathematics)
by Marshall Slemrod and Amit Acharya
Given an autonomous system of Ordinary Diff erential Equations without an a priori split into slow and fast components, we defi ne a strategy for producing a large class of `slow' variables (constants of fast motion) in a precise sense. The equation of evolution of any such slow variable is deduced. The strategy is to rewrite our system on an in finite dimensional "history" Hilbert space X and defi ne our coarse observation as a functional on X.
Reducing the number of degrees of freedom
I have been reading the book by Prof Anil K Chopra on Structural Dynamics. You might all be aware that Prof Chopra is from University of California Berkeley.
I have been reading the chapter 14, wherein the author talk of reducing the dynamic degrees of freedom using Rayleigh Ritz method.My question is, in commercial FE software , is the reduction of dynamic degrees of freedom practised?
If yes, what are the methods used? IS Rayl;eigh Ritz approiach used?
Kajal
Ph.D. Position at The Georgia Institute of Technology
I am looking for a Ph.D. student to work on geometric mechanics of growing bodies (both surface and bulk growth). Candidates with strong math and mechanics backgrounds are encouraged to apply. Interested candidates should email me (arash.yavari [at] ce.gatech.edu) their CV along with the names of three references.
Postdoctoral Fellow Position in Cardiovascular Mechanics
This position has been filled.
Postdoctoral postion in multiscale computational mechanics at RPI
There is an immediate opening for a postdoctoral research position in the Advanced Computational Research Laboratory at RPI, Troy NY to work on Multiscale Computational Mechanics. Encouraged to apply are creative, self-motivated candidates with a sound background in computational mechanics. RPI is home to the CCNI, one of the most powerful university-based super-computational research facilities in the world.
Qualifications:
1. PhD in Computational/Applied Mechanics/ Computational Materials Science or related topic.
Mechanics and chemical thermodynamics of phase transition in temperature-sensitive hydrogels
This paper uses the thermodynamic data of aqueous solutions of uncrosslinked poly(N-isopropylacrylamide) (PNIPAM) to study the phase transition of PNIPAM hydrogels. At a low temperature, uncrosslinked PNIPAM can be dissolved in water and form a homogenous liquid solution. When the temperature is increased, the solution separates into two liquid phases with different concentrations of the polymer. Covalently crosslinked PNIPAM, however, does not dissolve in water, but can imbibe water and form a hydrogel. When the temperature is changed