dynamics

Professor Ed Berger, Univeristy of Virginia Mechanical Engineering, is featured in the Chronicle of Higher Education for his use of web technologies and, in particular, "video solutions" for teaching undergraduate mechanics courses.

Please see attachment for details of Computational Mechanics researcher openings at Industrial Research (www.irl.cri.nz), a Crown Research Institute in beautiful New Zealand.

The role involves the application of advanced modeling and simulation methods to research on solids and structures, with an emphasis on complex systems such as composites and meta-materials, or solids with multiple defects and discontinuities.

The position is research oriented but also provides opportunities to consult with industry on commercial projects.

Candidates with expertise in theory and computation of elastic wave propagation, the mechanical behavior of composites, structural dynamics, or acoustics are encouraged to apply.

You are cordially invited to submit an abstract to the symposium on “Emerging Methods To Understand Mechanical Behavior” at 2008 TMS annual meeting, New Orleans, LA, March 9-13, 2008.  

Rui Huang and Se Hyuk Im, Physical Review E 74, 026214 (2006).

A stressed thin film on a soft substrate can develop complex wrinkle patterns. The onset of wrinkling and initial growth is well described by a linear perturbation analysis, and the equilibrium wrinkles can be analyzed using an energy approach. In between, the wrinkle pattern undergoes a coarsening process with a peculiar dynamics. By using a proper scaling and two-dimensional numerical simulations, this paper develops a quantitative understanding of the wrinkling dynamics from initial growth through coarsening till equilibrium. It is found that, during the initial growth, a stress-dependent wavelength is selected and the wrinkle amplitude grows exponentially over time. During coarsening, both the wrinkle wavelength and amplitude increases, following a simple scaling law under uniaxial compression. Slightly different dynamics is observed under equi-biaxial stresses, which starts with a faster coarsening rate before asymptotically approaching the same scaling under uniaxial stresses. At equilibrium, a parallel stripe pattern is obtained under uniaxial stresses and a labyrinth pattern under equi-biaxial stresses. Both have the same wavelength, independent of the initial stress. On the other hand, the wrinkle amplitude depends on the initial stress state, which is higher under an equi-biaxial stress than that under a uniaxial stress of the same magnitude.