Blog posts

Dear all,

Our group has recently published a paper on self-sealing of cementitious materials by using water-swelling rubber particles as admixtures. This is the first time that such an approach was developed to increase the water-tightness of cracks and therefore enhance the concrete durability.

The paper can be found at: https://www.researchgate.net/publication/319208857_Self-Sealing_Cementi…

Regards

Chiqun Zhang            Amit Acharya            Noel J. Walkington            Oleg D. Lavrentovich

Motivated by recent experiments, the isotropic-nematic phase transition in chromonic liquid crystals is studied. As temperature decreases, nematic nuclei nucleate, grow, and coalesce, giving rise to tactoid microstructures in an isotropic liquid. These tactoids produce topological defects at domain junctions (disclinations in the bulk or point defects on the surface). We simulate such tactoid equilibria and their coarsening dynamics with a model using degree of order, a variable length director, and an interfacial normal as state descriptors. We adopt Ericksen's work and introduce an augmented Oseen-Frank energy, with non-convexity in both interfacial energy and the dependence of the energy on the degree of order. A gradient flow dynamics of this energy does not succeed in reproducing some simple expected feature of tactoid dynamics. Therefore, a strategy is devised based on continuum kinematics and thermodynamics to represent such features. The model is used to predict tactoid nucleation, expansion, and coalescence during the process of phase transition. We reproduce observed behaviors in experiments and perform an experimentally testable parametric study of the effect of bulk elastic and tactoid interfacial energy parameters on the interaction of interfacial and bulk fields in the tactoids.

August 18, 2017

Dear Colleagues:

The Division of Civil, Mechanical and Manufacturing Innovation (CMMI) in the Directorate for Engineering (ENG) announces a nationwide search to fill a Program Director position for the Mechanics of Materials and Structures (MOMS) program.

Formal consideration of interested applications will begin September 15, 2017, and will continue until a selection is made with an intended start date of January, 2018.

We present theoretical and experimental descriptions of the elasticity of cylindrical micellar filaments using micro-mechanical and continuum theories, and Atomic Force Microscopy. Following our micro-mechanical elasticity model for micellar filaments [Asgari, Eur. Phys. J. E 2015, 38(9)], the elastic bending energy of hemispherical end caps is found. The continuum description of the elastic bending energy of a cylindrical micellar filament is also derived using constrained Cosserat rod theory.

The Boston University Department of Mechanical Engineering anticipates two openings for tenure-track junior faculty positions, pending approval by the Provost. These positions are in Emerging Areas of Mechanical Engineering such as Additive Manufacturing, Multifunctional Materials, Photoacoustic Imaging, and Sustainable Energy Systems. 

Dear Colleagues,

Attached please find our recent paper “Localized Deformation in Plastic Liquids on Elastomers”.

Title: Localized Deformation in Plastic Liquids on Elastomers

Authors: Xavier P. Morelle, Ruobing Bai and Zhigang Suo

A PhD position is available in the Soft Robotic Matter group @AMOLF, Amsterdam, the Netherlands. The PhD focusses on the development of a complete soft artificial biocompatible heart. For more information and to apply, please visit the AMOLF website.

We have an immediate opening for a research assistant in the Mech Engng department at IISc Bangalore. 

Requirements:

• Strong background in Finite element methods
• Skill in C++ programming
• Masters degree with specialization in computational mechanics, applied mathematics or related areas.
• Open only to Indian citizens.

Interested candidates satisfying ALL the above requirements can write to

rram at mecheng dot iisc dot ernet dot in