In a message dated 25/10/2007, johnjan@........ writes:

This is  an interesting point that Randall makes.  I suppose if there 
is  always some movement due to microseisms, then the static friction 
will not  come into play...  but maybe not .... at the end of each 
swing it may  be a factor anyway, causing the response to be nonlinear.
Hi All,
 
    If you have simple rolling of a hard cylinder /  sphere on another hard 
surface, no direct friction will be involved, although a  small loss will occur 
as the rolling surfaces are elastically compressed. If you  have any sliding, 
the movement will alternate from one stick / slip  situation to another in 
small jerky steps. 

I wonder  if there are also complexities of this sort in other types of hinge 
that  involve flexure of a material?
    In the V suspension shown, vibrations will tend to  flex the rods and 
will probably markedly increase the loss in the suspension due  to sliding 
friction. _http://home.earthlink.net/~meredithlamb/id1.html_ 
(http://home.earthlink.net/~meredithlamb/id1.html) 



Regards,
 
    Chris Chapman



   





In a message dated 25/10/2007, johnjan@........ writes:
<=
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  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>This is=20
  an interesting point that Randall makes.  I suppose if there 
is=20
  always some movement due to microseisms, then the static friction 
will=
 not=20
  come into play...  but maybe not .... at the end of each 
swing it=
 may=20
  be a factor anyway, causing the response to be nonlinear.
Hi All,
 
    If you have simple rolling of a hard cylinder /=
=20
sphere on another hard surface, no direct friction will be involved, althoug=
h a=20
small loss will occur as the rolling surfaces are elastically compressed. If=
 you=20
have any sliding, the movement will alternate from one stick / sli=
p=20
situation to another in small jerky steps. 
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>I wonder=20
  if there are also complexities of this sort in other types of hinge that=20
  involve flexure of a material?
    In the V suspension shown, vibrations will tend=
 to=20
flex the rods and will probably markedly increase the loss in the suspension=
 due=20
to sliding friction. http://home.earthl=
ink.net/~meredithlamb/id1.html


 
    Regards,
 
    Chris Chapman