From: "Roy Diffrient" 
To: =?Windows-1252?Q?Rapha=EBl_Guinamard?= ,
   "ATM" 
Reply-To: "Roy Diffrient" 


I think the GRAPE software already includes the effects of Hooke's Law.
Otherwise, there would be a greater difference in the results.

Roy Diffrient
Monkton, MD
UDA

----- Original Message -----
From: "Rapha‰l Guinamard" 
To: "ATM" ; "Roy Diffrient"

Sent: Saturday, December 28, 2002 5:17 AM Subject: Re: ATM Re: Structural
truss analysis - initial findings


> Roy wrote
> > >
> > > First, forget about bending.  Truss stiffness does not result from
> > > resistance to bending
> .
> .
> > > Have you read about Hooke's Law? It says that the change in length of
an
> elastic
> > > material (such as a metal shape) in tension or compression is
calculated
> > by
> > > the equation P L / (A E),
> > > Those changes in length are sufficient to directly cause truss
> deflection
>
> Roy,
> If I understand correctly, this means that all the fantastic work done by
> Tom is only one part of the problem...
> I suppose that Grape is not able to calculate the effect of Hooke's law?
(is
> it true Tom?)
> Do you know if another sofware is able to calculate this effect?
> Could we simply add the change of position you mentioned here
> http://astro.umsystem.edu/atm/ARCHIVES/APR00/msg00921.html to the
deflection
> of grape
> http://overton.tamu.edu/aset/krajci/truss-analysis/truss-analysis.htm to
> have a more accurate result ?
>
> Rapha‰l Guinamard
>
>

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