View Single Post
Old 12-22-2010, 09:01 AM   #6
Erick Mead
 
Erick Mead's Avatar
Dojo: Big Green Drum (W. Florida Aikikai)
Location: West Florida
Join Date: Jun 2005
Posts: 2,619
United_States
Offline
Re: Does Extension Mean Straight? or Central Axis Neither Central Nor Axis?

Quote:
Lee Salzman wrote: View Post
It's easiest to show the idea through a few very badly drawn stick figures. ... There is absolutely no engineering or physics rigor in what follows, just bad subjective argument, so please forgive me in advance.

Then I was asked to consider something else:
Attachment 824

Pure juice from foot to hand felt as the uniform act of extending throughout, but no stresses going across. Just extending through in a clean arc along the entire body without sharp angles. Extension, I think the word did not mean what I thought it meant.
You do not give yourself enough credit.... While you may not have the circles/arrows just right -- you adequately described a structure undergoing spontaneous shear displacements resulting from eccentric load paths -- and then you showed the correct solution which is a funicular (cable-shaped) curve -- which by definition is a structural loading with zero shear and zero bending forces...

The fun part is extending the implications of that observation to configurations (and dynamics) that look almost nothing like that simple curve (e.g.-- looping spiral action, whether absorptive or intensively expressive (think whip-cracking)) and actuating that structural principle in the body of another to exploit any discontinuity within it. But they are all precisely the same in terms of loading principles and spontaneous displacements.

Cordially,

Erick Mead
一隻狗可久里馬房但他也不是馬的.
  Reply With Quote