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RE: Thin-walled compound cross-sections shareware ?

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First of all, I would like to thank you Bill, Terry, Raghu and Graham
for your quick replies.

Actually, what I am looking for is an inexpensive program
that calculates shear area and 2nd moments of inertia
of thin-walled compound cross-sections.

I have to check frequently dynamic analyses done by subcontractors.
Often these are rc-structures with shear walls and cores. The quickest
way to check such calculations is to create a small model of 3-D beam
elements. The rc-cores are often thin-walled compound cross-sections
which I usually represent by a beam with a shear and flexural rigidity.
Hence, the program I am looking for shall be able to calculate the shear
effective shear area and 2nd moments of inertia - incl. torsional.

The responses which I received by now are not addressing fully
my problem - I believe that the algorithm built-in in Autocad as well
as in Shape Builder does not treat the separate elements as thin-walled
(e.g.  the deformation of the cross-section along the beam axis due to
warping as well as shear loading is neglected, i.e. the assumtion that
QS remain even is preserved).

Please correct me if I am wrong in my assumption about Autocad and Shape
Builder. I do not have access to both programs.

Thanks in advance,

Peter Rangelow
Hochtief AG,
Frankfurt, Germany

=========================== 1 =======================
Von: Bill Allen, S.E.
An: 'seaoc(--nospam--at)'
Betreff: RE: Thin-walled compound cross-sections shareware ?
Datum: Donnerstag, 29. Januar 1998 17:08

This isn't a "cheap" solution, but may be if you have AutoCAD.
AutoCAD will calculate these properties for you. In R14, you
convert your objects to a region (Draw/Region then select the
objects you want to convert). Once you have a region, you can
type at the command line "massprop" and then select all of the
objects. the following is a sample of results (using a pipe):

Command: massprop

.... explanation follows ...

You should be mindfull of where you are drawing your
object with respect to the global X-Y axis.

Hope this helps,

=========================== 2 =======================
Von: Terry Kubat
An: Rangelow, Peter           HVIK
Betreff: Section properties
Datum: Donnerstag, 29. Januar 1998 19:25

Mr. Rangelow,

IES has a tool called ShapeBuilder that currently calculates
the basic geometric properties for built-up sections.  It is
a graphical tool that is very easy to use.  The version 1.0
product that we currently sell, for $95 US, will calculate
the following:
    Area (A)
    Moments of inertia (I)
    Section modulus (S)
    Radius of gyration (r)
    Torsion constant (J)
The software has a database of AISC steel shapes and NDS
wood shapes (SS, GL).  I am currently working on a version
2.0 that will also calculate more of the shear properties
(shear center, warping constant, etc.)  This version should
be available within a couple months.

For more information you might visit our web site at

Terry Kubat
IES Support Engineer, support(--nospam--at)
phone: 406/586-2665, fax: 406/586-5671

=========================== 3 =======================
Von: Raghu S. pendyala
An: seaoc(--nospam--at)
Betreff: Re: Thin-walled compound cross-sections shareware ?
Datum: Freitag, 30. Januar 1998 06:03

Doesn't seem to work with Autocad LT.

Raghu Pendyala
Pendyala Consulting, Civil and Structural Engineers
Melbourne, Australia

=========================== 4 =======================
Von: graham.fitch(--nospam--at)
An: seaoc(--nospam--at)
Betreff: Re: Thin-walled compound cross-sections shareware ?
Datum: Montag, 2. Februar 1998 21:37

On Thu, 29 Jan 1998 16:49:00 +0100, rangelow.peter(--nospam--at)

>Do you know of some good and inexpensive program
>that calculates shear area and 2nd moments of inertia
>of thin-walled compound cross-sections?

I haven't seen it for a few years but I seem to recall that Roark's
Formulas is/was
available in spreadsheet form.  Would that be the kind of thing you were
looking for?

Graham Fitch
Chartered Civil and Structural Engineer