continuum mechanics

Chemo-thermal model and Gaussian process emulator for combustion synthesis of Ni/Al composites

https://www.sciencedirect.com/science/article/pii/S0950061818322116 The mechanical behavior of masonry materials has a common feature: a nonlinear behavior with high compressive strength and very low tensile strength. As a consequence, old masonry buildings generally present cracks due to permanent loads and/or accidental events. Therefore, the characterization of the global dynamic behavior of masonry structures should take into account the presence of existing cracks.

https://www.annalsofgeophysics.eu/index.php/annals/article/view/8025 https://www.researchgate.net/publication/331199456_Experimental_and_nume... This paper presents a study on the seismic response of the San Frediano bell tower in Lucca.

Amit Acharya

(in Journal of Elasticity)

The kinematic theory of Weingarten-Volterra line defects is revisited, both at small and finite deformations. Existing results are clarified and corrected as needed, and new results are obtained. The primary focus is to understand the relationship between the disclination strength and Burgers vector of deformations containing a Weingarten-Volterra defect corresponding to different cut-surfaces.

We are looking for a postdoctoral research fellow who has experience with developing and implementing computational algorithms for simulation and optimization in structural mechanics.
He or she will be involved in an interdisciplinary project for the development of a computational framework for the design of functional, smart, performance textiles. The objective is to develop and implement novel computational algorithms for a multi-scale and multi-physics simulation of functional textiles and fabrics, which will be at the core of a multifunctional design optimization framework. The position requires a deep understanding of structural mechanics concepts, as well as experience in algorithm development for computational simulation and optimization.

Chiqun Zhang            Amit Acharya

The utility of the notion of generalized disclinations in materials science is discussed within the physical context of modeling interfacial and bulk line defects like defected grain and phase boundaries, dislocations and disclinations. The Burgers vector of a disclination dipole in linear elasticity is derived, clearly demonstrating the equivalence of its stress field to that of an edge dislocation. We also prove that the inverse deformation/displacement jump of a defect line is independent of the cut-surface when its g.disclination strength vanishes. An explicit formula for the displacement jump of a single localized composite defect line in terms of given g.disclination and dislocation strengths is deduced based on the Weingarten theorem for g.disclination theory at finite deformation. The Burgers vector of a g.disclination dipole at finite deformation is also derived.

A PhD position is open for summer or fall 2017 in Advanced Hierarchical Materials by Design Lab at Louisiana Tech University on multiscale modeling of hierarchical materials with an emphasis on nanocomposites. The candidates must have earned a M.Sc. degree in Mechanical Engineering or related fields and have a solid background in theoretical and computational mechanics, specifically continuum mechanics and finite element modeling, and need to have the knowledge of writing computer code (preferably using C/C++).

Job title: Research Associate/Postdoc

Minimum qualification: PhD in Solid Mechanics/Mathematics

Research area: Thermoelastic Modeling of nano and Contunuum Rods – A Molecular Approach

Salary: Rs 36000 per month + 30% HRA

Walk in interview: 3rd of Nov 2016 in Department of Applied Mechanics, IIT Delhi

Contact person: Prof. Ajeet Kumar, ajeetk@am.iitd.ac.in

See the attachment for more details.

A PhD position is available in the Department of Mechanical Engineering and Engineering Science at the University of North Carolina at Charlotte. The research project is on the multiscale modeling of the stress corrosion cracking. Candidates should have a strong background in continuum mechanics, finite elements and constitutive modeling. Programming experience in Fortran or C++ is required for this position. The starting date for this position is January 2017.

Chiqun Zhang          Xiaohan Zhang         Amit Acharya          Dmitry Golovaty          Noel Walkington

Nonsingular disclination dynamics in a uniaxial nematic liquid crystal is modeled within a mathematical framework where the kinematics is a direct extension of the classical way of identifying these line defects with singularities of a unit vector field representing the nematic director. It is well known that the universally accepted Oseen-Frank energy is infinite for configurations that contain disclination line defects. We devise a natural augmentation of the Oseen-Frank energy to account for physical situations where, under certain conditions, infinite director gradients have zero associated energy cost, as would be necessary for modeling half-integer strength disclinations within the framework of the director theory. Equilibria and dynamics (in the absence of flow) of line defects are studied within the proposed model. Using appropriate initial/boundary data, the gradient-flow dynamics of this energy leads to non-singular, line defect equilibrium solutions, including those of half-integer strength. However, we demonstrate that the gradient flow dynamics for this energy is not able to adequately describe defect evolution. Motivated by similarity with dislocation dynamics in solids, a novel 2D-model of disclination dynamics in nematics is proposed. The model is based on the extended Oseen-Frank energy and takes into account thermodynamics and the kinematics of conservation of defect topological charge. We validate this model through computations of disclination equilibria, annihilation, repulsion, and splitting. We show that the energy function we devise, suitably interpreted, can serve as well for the modeling of equilibria and dynamics of dislocation line defects in solids making the conclusions of this paper relevant to mechanics of both solids and liquid crystals.

PhD project 2 (Reference: NGCM-0080)

Design and optimisation of bio-inspired programmable surfaces with active materials

Biotribology Group, nCATS
Faculty of Engineering and the Environment
University of Southampton, United Kingdom

Background

PhD project 1 (Reference: NGCM-0011)

Generalised asymptotic numerical methods for buckling instability problems in biological systems and bio-inspired morphing structures

Biotribology Group, nCATS
Faculty of Engineering and the Environment
University of Southampton, United Kingdom

Background

WHAT

Five-day short course on the fundamentals of continuum, atomistic and multiscale modeling of materials.

WHO

Prof. Ellad B. Tadmor (U. Minnesota, USA) and Prof. Ronald E. Miller (Carleton University, Canada).

WHERE

Friedrich-Alexander-Universität (FAU), Erlangen-Nürnberg, Germany

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  WYNDHAM GRAND Hotel, Inciralti Izmir/Turkey during August 5-7, 2015.