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an interesting puzzle: multiscale mechanics

Submitted by Henry Tan on

an interesting puzzle for fun:

Lame’s classical solution for an elastic 2D plate, with a hole of radius a and uniform tensile stress applied at the far field, gives a stress concentration factor (SCF) of two at the edge of the hole. This SCF=2 is independent of the hole radius.

Consider what happened to this concentration factor if the radius a approaches infinitely small. The SCF is independent of a, so it remains equal to two even when the hole disappears.

Flip test: imagine continuum mechanics as a revolutionary idea

Submitted by Zhigang Suo on

Let's say the world has only e-books, then someone introduces this technology called 'paper.' It's cheap, portable, lasts essentially forever, and requires no batteries. You can't write over it once it's been written on, but you buy more very cheaply. Wouldn't that technology come to dominate the market?

How "hot" is a research topic?

Submitted by Pradeep Sharma on

A student pointed me to a recent article on physicsweb. This article discusses a new (scientific) ranking system developed by a German student (Michael Banks) in Max Planck Institute of Solid State Physics to characterize the "hotness" of the scientific subject. If, after reading the popular physicsweb article linked above, you are interested in more details you may wish to read the attached original article posted by Banks. "Carbon nanotubes" emerges at the top of the list.