Blog posts

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         Marta Lewicka         Mohammad Reza Pakzad

In Nonlinearity, 29, 1769-1797

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 infimum value
of the appropriate incompatibility energy, resembling "non-Euclidean elasticity".  We then derive a
Γ-convergence result for the dimension reduction from 3d to 2d in the Kirchhoff energy scaling
regime. A practical implementation of the algebraic conditions of integrability is also discussed.

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

Dear colleagues,

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

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

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 [at] uniri.hr