Jon Ellison Wrote:
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> Dr. Troglodyte Wrote:
> --------------------------------------------------
> -----
> >
>

[Image Restored]
> >
> >
> > Hello Jon Ellison; regarding the above image
> you
> > wrote:
> >
> > ”Not really as it isn't an arch.
> > It's a triangulated, opposed truss.
> > It functions dynamically in exactly the same
> way
> > as the trusses' in the other pyramids...”
> >
> > These comments are incorrect.
> >
> > The roof structure for this space is an
> > arch. It is composed of segments of
> opposing
> > voussoirs. It is not a
> > “triangulated, opposed truss”; in that it
> does
> > satisfy the formulaic requirements for a truss:
> > m = 2n – 3,
> > where m is the
> > total number of members and
> > n is the total
> > number of nodes. It does not function
> > “dynamically” as a truss, for the same
> > reason.
> >
> >
> >
>
> >
> >
> >
> > Dr. Troglodyte
>

> How exactly does a Voussoir function as an active
> component within a true arch????
> How does a true arch function as opposed to a
> gabled arch???
> Are they the same?
> Are they different??


The ‘voussoir’ is a wedge shaped element utilized in load [force/thrust] transference. In the image below, lines of “thrust” are dashed:



Source


> What is the difference between a True Arch and a
> False Arch??


The ‘voussoired’ arch is a form of “true” arch; the ‘corbeled’ arch is defined as a “false” arch.


> What would happen if we were to remove the lower
> cross member from a triangulated truss??
> If the lower cross member of a truss were removed
> could it be compensated for in any other way
> therefore mathematically maintaining the
> structural integrity of the truss??
>


You would no longer have a ”truss”. Compensation of the horizontal chord member of a truss, that does not act in tension, negates its designation as a ”truss”.


> I look forward to your answers.
>
> I have corrected and completed your drawing.
>
>



You have “corrected” nothing. You have illustrated the compression of the diagonal members and the tension of the horizontal chord member. You have incorrectly illustrated the “reaction” force from the bearing nodes, as indicated in this modern wood truss image:



Source



Dr. Troglodyte