Ahmed Elbanna's blog

A wide range of engineered and natural composites exhibit a layered architecture whereby individual building blocks are assembled layer by layer using cohesive interfaces. We present a novel mechanism for evolving acoustic band gap structure in a model system of these composites through patterning the microstructure in a way that triggers non-planar interfacial deformations between the layers as they are stretched.

Dear Colleagues,

We would like to invite you to consider submitting abstracts to the following minisymposium taking place as part of the Soceity of Engineering Sciences meeting to be hosted by the University of Maryland (October 4-7, 2016)

D-9 :Friction, Fracture and damage (http://ses2016.org/symposium-d-9-friction-fracture-and-damage/)

Ahmed Elbanna (University of Illinois Urbana Champaign) and K. Ravi-Chandar (University of Texas at Austin)

Friction and deformation in granular fault gouge are among various dynamic interactions associated with seismic phenomena that have important implications for slip mechanisms on earthquake faults. To this end, we propose a mechanistic model of granular fault gouge subject to acoustic vibrations and shear deformation. The grain-scale dynamics is described by the Shear-Transformation-Zone theory of granular flow, which accounts for irreversible plastic deformation in terms of flow defects whose density is governed by an effective temperature.

Transfer printing, an emerging manufacturing technique for heterogeneous material integration, is combined with the unique mechanics of soft composite films to realize a responsive surface for tunable topography in this work. Soft composite films are fabricated by transfer printing thin silicon ribbons on elastomeric films in a staggered manner. The corrugation formation in soft composite films requires a well-organized spatial distribution of the silicon ribbons which is enabled by transfer printing processes developed here.

Our experience with earthquakes is that they are violent events that take a heavy toll on our societies through life and property losses. However, earthquakes present us with some of the most challenging questions in mechanics. By better understanding the nucleation and propagation dynamics of earthquakes, we may make progress towards minimizing their negative impact. Insights from mechanics may help in the development of better seismic hazard models as well as in the construction of more efficient earthquake early warning systems.

Prof. Jim Rice delivered the 2015/2016 Nathan Newmark Distinguished lecture at University of Illinois Urbana Champaign. This lecture series, organinzed by the Structural Engineering group at UIUC, honors the memory of Prof. Newmark who was an influential figure in computational mathematics, structural dynamics and earthquake engineering. A link to Prof. Rice's lecture can be found here: https://www.youtube.com/watch?v=Ec2y79TVOog

Best,

Ahmed