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Min Yi's picture

A constraint-free phase field model for ferromagnetic domain evolution

A continuum constraint-free phase field model is proposed to simulate the magnetic domain evolution in ferromagnetic materials. The model takes the polar and azimuthal angles (ϑ1, ϑ2), instead of the magnetization unit vector m(m1,m2,m3), as the order parameters. In this way, the constraint on the magnetization magnitude can be exactly satisfied automatically, and no special numerical treatment on the phase field evolution is needed. The phase field model is developed from a thermodynamic framework which involves a configurational force system for ϑ1 and ϑ2.

Jamie Guest's picture

Journal Club Theme of January 2015: Topology Optimization for Materials Design

Processing technologies are rapidly advancing and manufacturers now have the ability to control material architecture, or topology, at unprecedented length scales. This opens up the design space and provides exciting opportunities for tailoring material properties through design of the material’s topology. But as seen many times in history with advancements in materials and processing technologies, the natural default is to rely on familiar shapes and structure topologies.

Amit Acharya's picture

The metric-restricted inverse design problem

Amit Acharya         Marta Lewicka         Mohammad Reza Pakzad

We study a class of design problems in solid mechanics, leading to a variation on the
classical question of equi-dimensional embeddability of Riemannian manifolds. In this general new
context, we derive a necessary and sufficient existence condition, given through a system of total
differential equations, and discuss its integrability. In the classical context, the same approach
yields conditions of immersibility of a given metric in terms of the Riemann curvature tensor.
In the present situation, the equations do not close in a straightforward manner, and successive
differentiation of the compatibility conditions leads to a more sophisticated algebraic description
of integrability. We also recast the problem in a variational setting and analyze the infimum value
of the appropriate incompatibility energy, resembling "non-Euclidean elasticity".

Two Funded PhD positions in fatigue of bolted structures

Two funded PhD positions are available in the Department of Civil and Geological Engineering at the University of Saskatchewan.

 

 

 

Employment Opportunity - Program Directors at NSF

Dear Colleague Letter: Division of Civil, Mechanical and Manufacturing Innovation (CMMI), Mechanics of Materials and Structures (MoMS) – Employment Opportunity for Program Director Positions (Open Until Filled)

http://www.nsf.gov/pubs/2015/cmmi15001/cmmi15001.jsp?WT.mc_id=USNSF_147

NSF - Mechanics of Materials and Structures

Dear colleagues,

There have been two changes at NSF that do affect the imechanica community. I would like to bring these to your attention.

INTERNSHIP SIMULATION OF LARGE SCALE FRACTURE UNIVERSITY OF LUXEMBOURG (variational theory)

Dear All, Please see the attachment. We are looking only for an MSc student intern who is enrolled in a Higher Education Institution (in the European Union). The topic is the variational theory of fracture for microchip manufacturing. Connections to a relevant company in France are possible. Please see also, in the attachment, our 2014 Computational Mechanics Lab Report and our best wishes for 2015. Regards, Stéphane and the team. Best wishes for 2015: http://hdl.handle.net/10993/19425

Gordan Jelenić's picture

Post-doctoral position in Computational Mechanics

One post-doctoral Research Associate in Computational Mechanics is sought to work on the Croatian Science Foundation project No. 1631 'Configuration-dependent Approximation in Non-linear Finite-element Analysis of Structures' on a full-time fixed-term contract for the duration of three years and six months or until the project financing has expired.

The project explores the configuration-dependent interpolation as a novel, unorthodox and remarkably promising expansion of the framework within which the non-linear finite-element method has been traditionally contained. The basic idea underlying the project stems from an apparent disparity between the rather advanced extensions of the traditional linear finite-element principles to non-linear problems and the fact that the key finite-element concept – that of interpolation of the unknown functions – is surprisingly kept mostly constant, i.e. configuration-independent. Enabling the finite-element approximation to become configuration-dependent is motivated by the existing need to improve the current non-linear finite-element procedures, in particular for mechanical problems defined on non-linear manifolds. This principle is presented as the general concept providing viable novel development paradigm with obvious benefits for a wider class of mechanical problems. The configuration-dependent approximation to be designed shall obey the essential convergence requirements, with its extra flexibility (arising from the potential of the new approximation to vary with the configuration) employed to improve the solution in some clearly defined manner.

More detail in the attachment.

Closing date for application: 16. January 2015

Gross salary: €20.000 per annum

Further inquiries: gordan.jelenic@uniri.hr

Alejandro Mota's picture

Call for Abstracts: USNCCM13 Minisymposium 414 on Recent Advances in Mesh Adaptivity for Inelasticity, Damage, Crack Propagation and Failure.

In this minisymposium we seek to highlight challenging problems in computational solid mechanics that require mesh adaptation methods for their solution. We focus on the finite element method and works that address large deformations and the accompanying inelasticity, damage, crack propagation and failure. Discussion will center on Lagrangian descriptions and determining the necessary computational components to resolve, preserve, and evolve the fields that govern these processes. Prototypical material systems may include, but are not limited to, ductile metals and biomaterials.

The rheology of non-dilute dispersions of highly deformable viscoelastic particles in Newtonian fluids

Abstract: We present a model for the rheological behaviour of non-dilute suspensions of initially spherical viscoelastic particles in viscous fluids under uniform Stokes flow conditions. The particles are assumed to be neutrally buoyant Kelvin–Voigt solids undergoing time-dependent finite deformations and exhibiting generalized neo-Hookean behaviour in their purely elastic limit. We investigate the effects of the shape dynamics and constitutive properties of the viscoelastic particles on the macroscopic rheological behaviour of the suspensions.

Jaafar El-Awady's picture

Unravelling the physics of size-dependent dislocation-mediated plasticity

Size-affected dislocation-mediated plasticity is important in a wide range of materials and technologies. The question of how to explain and predict the effect of size on the properties and response of materials has been at the forefront of mechanics and materials research.

Open Postdoctoral Position in Computational Science and Engineering

The University of Notre Dame, Center for Shock Wave-processing of Advanced Reactive Materials (C-SWARM), is seeking a highly qualified candidate for a Postdoctoral Research Associate position in the area of computational mechanics/physics. C-SWARM is a newly established center of the emerging field of predictive science. The main mission of C-SWARM is to predict shock conditions under which new materials can be synthesized using predictive computational models that are verified and validated with quantified uncertainty on future high-performance Exascale computer platforms.

mohsenzaeem's picture

Two-phase solid–liquid coexistence of Ni, Cu, and Al by molecular dynamics simulations using the modified embedded-atom method

The two-phase solid–liquid coexisting structures of Ni, Cu, and Al are studied by molecular dynamics (MD) simulations using the second nearest-neighbor (2NN) modified-embedded atom method (MEAM) potential. For this purpose, the existing 2NN-MEAM parameters for Ni and Cu were modified to make them suitable for the MD simulations of the problems related to the two-phase solid–liquid coexistence of these elements.

Functional Materials Far from Equilibrium - GW4 meeting

Please find below the programme for tomorrow.

For directions to the Cardiff School of Mathematics, see
http://www.cardiff.ac.uk/maths/aboutus/directions/index.html

GW4 meeting 'Functional materials far from equilibrium', Cardiff 7 Jan 2015

The meeting will take place on 7 January in the Cardiff School of Mathematics in Senghennydd Road, Cardiff, in lecture theatre M/0.40 (ground floor) from 10 am-5 pm..
Lunch and coffee breaks will be in M/1.02 (first floor)

jansen's picture

2nd Workshop: Impact of mechanical and thermal loads on the long term stability of PV modules, 3 February 2015, Hannover

 

After the successful first edition organized by ISFH and held in Hamelin (Germany) in November 2013, ISD hosts the second edition of the workshop entitled “Impact of mechanical and thermal loads on the long term stability of PV modules”. On behalf of the ISD-ISFH consortium, we are pleased to invite you to participate at this event. This is a great opportunity for meeting colleagues active in this area and discussing new ideas and establishing links for future cooperation.

 

jkyang's picture

Call for Abstracts: Symposium on Acoustic Metamaterials and Phononic Crystals, ASME-McMAT 2015

First of all, Happy New Year to you all!

We would like to invite you to participate in the Symposium on Acoustic Metamaterials and Phononic Crystals at the ASME 2015 Applied Mechanics and Materials Conference (McMAT2015) to be held this summer from June 29 to July 1, 2015 in Seattle, Washington. 

ndaphalapurkar's picture

Postdoc position – Modeling dynamic fracture and fragmentation

A Postdoctoral fellowship is available at The Johns Hopkins University, Baltimore, U.S.A. in the area of fracture and fragmentation under dynamic loading conditions. The potential candidate should have a Ph.D. in an engineering discipline, a strong background in fracture mechanics and extensive computational modeling experience working with the finite element methods or some other numerical method with application to solid mechanics.

Research Associate-Modelling of 3rd Generation Artificial Turf

Loughborough University - Wolfson School of Mechanical and Manufacturing Engineering

Fixed-Term for 12 Months

mohsenzaeem's picture

A Review of Quantitative Phase-Field Crystal Modeling of Solid–Liquid Structures

Phase-field crystal (PFC) is a model with atomistic-scale details acting on diffusive time scales. PFC uses the density field as its order parameter, which takes a constant value in the liquid phase and a periodic function in the solid phase. PFC naturally takes into account elasticity, solid–liquid interface free energy, surface anisotropy, and grain boundary free energy by using this single-order parameter in modeling of coexisting solid–liquid structures.

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