Rajesh,
The subject of friction is conveniently reduced to its simplest form of F=mu*N where mu is the coefficient of friction in the limit and N is the force normal to the plane to which the force F is applied. The definition of mu "in the limit" refers to the fact that the body is about to move or moving. This gives the lowest level of F.
Any body that is not at this limiting state will require a greater force F to bring it to the limit. The term used in mechanical engineering to represent this state is "stiction" derived presumably from the term "stick".
Suggest that theory may be more eloquently explain in such text as Hicks Mechanical Engineering or Machinery's Handbook. Perhaps the tribologists amonst us can add to this explanation.
Geoff Stone
--- Rajesh_V_Balapure@ril.com wrote:
<HR>
<html><body>
<tt>
Hi Every body,
I have following queries:-
kindly tell me whether we can consider friction as a non continuous force ( in the sense that it is not always acting, active only during installation to hot and other thermal cycles).
From what I remember friction coeffecient is area independent.So whether we use a knife edge support or a support with a finite area , in my opinion the friction force should remain same.Am I correct? If we have to consider a guide or directional limit stop ( with zero gap) as a rotational stop also ,then the friction force at these points must equal a force couple which is required to prevent rotation. Can friction generate such a magnitude of force couple which will make the joint rotationally rigid ( as if we model such a support as rotational restraint also, Caesar considers it as a rigid rotational restraint with near infinity stiffness). So is it logical to consider such supports as rigid rotational restraint ?
Regads ,
Raj.
</tt>
<!-- |**|begin egp html banner|**| -->
<table border=0 cellspacing=0 cellpadding=2>
<tr bgcolor=#FFFFCC>
<td align=center><font size="-1" color=#003399><b>Yahoo! Groups
Sponsor</b></font></td>
</tr>
<tr bgcolor=#FFFFFF>
<td align=center width=470><table border=0 cellpadding=0 cellspacing=0><tr><td
align=center><font face=arial size=-2>ADVERTISEMENT</font><a
href="<a href="http://rd.yahoo.com/M=215002.1954253.3462811.1261774/D=egroupweb/S=1705083319:HM/A=1000239/R=0/*http://ads.x10.com/?bHlhaG9vaG0xLmRhd=1017742088%3eM=215002.1954253.3462811.1261774/D=egroupweb/S=1705083319:HM/A=1000239/R=1">http://rd.yahoo.com/M=215002.1954253.3462811.1261774/D=egroupweb/S=1705083\
319:HM/A=1000239/R=0/*http://ads.x10.com/?bHlhaG9vaG0xLmRhd=1017742088%3eM=21500\
2.1954253.3462811.1261774/D=egroupweb/S=1705083319:HM/A=1000239/R=1</a>"
target=_top><img
src="<a href="http://ads.x10.com/?Z3lhaG9vaG0xLmRhd=1017742088%3eM=215002.1954253.3462811.1261774/D=egroupweb/S=1705083319:HM/A=1000239/R=2">http://ads.x10.com/?Z3lhaG9vaG0xLmRhd=1017742088%3eM=215002.1954253.3462811\
.1261774/D=egroupweb/S=1705083319:HM/A=1000239/R=2</a>"
alt="" width="300" height="250" border="0"></a></td></tr></table></td>
</tr>
<tr><td><img alt="" width=1 height=1
src="<a href="http://us.adserver.yahoo.com/l?M=215002.1954253.3462811.1261774/D=egroupmail/S=1705083319:HM/A=1000239/rand=438442725">http://us.adserver.yahoo.com/l?M=215002.1954253.3462811.1261774/D=egroupmai\
l/S=1705083319:HM/A=1000239/rand=438442725</a>"></td></tr>
</table>
<!-- |**|end egp html banner|**| -->
<tt>
<tt>Your use of Yahoo! Groups is subject to the <a
href="http://docs.yahoo.com/info/terms/">Yahoo! Terms of Service</a>.</tt>
</br>
This archive was generated by hypermail 2.1.8 : Tue Mar 04 2008 - 11:40:22 EST