research

Hi all.

I'm studying the high temperature viscoplastic behavior of titanium alloys. It is well known that at high temperature range, deformation induced dynamic recrystallization (DRX) causes dramatically strain softening. Such strain softening behavior is also treated as plastic instable according to literatures.

The Dynamical Systems program in the Directorate of Engineering and the Applied Mathematics Program in the directorate of Mathematical and Physical Sciences Sciences, of the National Science Foundation, have just published a joint "Dear Colleague Letter", expressing interest in special topics in Dynamical Systems.  The letter encourages unsolicited proposals on the following topics:

There are several exact relations from the theory of composites that can be used to determine whether a new numerical or analytical approach gives reasonable answers. Here's a paper on some exact relations that I wrote up a long time ago and just recently posted on Scribd. 

The cytoskeleton provides the mechanical scaffold and maintains the integrity of cells.  It is usually believed that one type of cytoskeleton biopolymer, microtubules, bear compressive force.  In vitro experiments found that isolated microtubules may form an Euler buckling pattern with a long wavelength for very small compressive force.  This, however, does not agree with in vivo experiments where microtubules buckle with short-wavelength.  In order to understand the structural role of microtubules in vivo, we (Jiaping Zhang and Hanqing Jiang) developed a mechanics model to study microtubule buckling supported by cytoplasm.  We found that the ability for a cell to sustain compressive force does not solely rely on mic