Pradeep Sharma's blog

Two post-doctoral fellow positions are available in Sharma's research group at University of Houston. Potential candidates can visit the following website to get an idea of the kind of research projects undertaken in this group: http://www2.egr.uh.edu/~psharma/index.html. The positions are for one year but renewable for a second year upon satisfactory performance. Candidates are expected to be familiar with both atomistic calculation methods and continuum mechanics.

For both mechanicians and physicists, linking continuum concepts to the underlying microscopic characteristics of materials has remained a major preoccupation. Certainly, with the recent advent of the so-called "multiscale" modeling approaches, this topic has been brought to a sharp focus. Cauchy stress is one such continuum concept that has courted a fair amount of controversy.

The Cullen College of Engineering of the University of Houston invites nominations and applications for the position of Chair of the Department of Mechanical Engineering (ME). As part of a major drive for excellence, the college seeks innovative and enthusiastic leadership to build upon the strengths of the research and educational programs of the ME Department. The successful candidate must possess academic skills and credentials of the highest caliber, with an established national and international reputation in research, and academic and professional leadership in Mechanical Engineering or related fields. Credentials appropriate to the rank of Professor are required.

I plan to submit the attached paper on quantum mechanical definition of stress in the next few weeks. Comments and feedback are welcome. Fair amount of work has been done on stress definition in the context of classical molecular dynamics (also attracting some controversies). In contrast, there appear to be several open issues in the quantum case. Hopefully, the attached paper provides a starting point.

Micromechanics---loosely speaking, is the study of heterogeneities in materials and its consequences for material or continuum behavior. This encompasses studies of inclusions, dislocations, cracks or more generally defects. A related problem is that of "coarse-graining" or in other words the effective homogenized properties of a heterogeneous material. The latter is a recurring theme in all of physical sciences not just solid mechanics. Micromechanics, a formidable subject by all means, dominated a substantial part of the history of solid mechanics. Several of our Timoshenko awardees have been associated with this subject, e.g. Eshelby, Hill, Keller, Irwin, Rice among others.

In a recent rapid communication (see attached paper), using principles of pattern formation, we expose some simple stategies to reliably produce perfect long range order in self-assembling systems. Most self-assembling systems exhibit short ranged order. This imperfection is detrimental to several practical applications. It is almost always possible to produce perfect patterns in small domain sizes but self-assembly over a larger areal span results in defects.

Xin-Lin Gao and I had the pleasure of guest-editing a special  issue on "scale effects in mechanics" for the journal, Mathematics and Mechanics of Solids (editor: Professor David Steigmann , UC Berkeley).

(Carbon) Nanotubes have attracted considerable attention from the mechanics community; probably second to none when it comes to nanotechnologies. Although I personally have done very little in this particular topic, I have enjoyed reading about the many developments made by mechanicians in terms of modeling the behavior of nanotubes and the applicability of standard continuum mechanics notions. A post on this subject on iMechanica, which received a fair amount of attention from many mechanicians involved in this topic, may be found here .