huangyhg

i want to use finite element to get properties in irrgular s
i'm not sure how you generate the shape. pca has a program that does exactly what you are trying to do (pcacol with irrcol add-on).
femap, available from enterprise software products, has the ability to do exactly what you are talking about. it is an fea pre/post processing code, but it will output the beam properties you are interested in.
if you have a shape which is formed by straight lines connecting
a number of points, this can be done mathematically by dividing
the enclosed area into an upper line and a lower line. take a base
below the lower line. take area and moments of the area bound
by the upper line and the baseline between adjacent nodes. do the
same for the lower line. subtract the latter from the former. you
will get the net area/ moment of inertia about the base line. i about
neutral axis can be found from the available results. looks complex,
but simple enough if you know the basics of integration. repeat the
same for the other axis.
if you have a shape which is not formed by straight lines, it can still
be executed by the above philosophy by integration.
by the way, why should anyone build an irregular shaped column?
not worth the effort! if it is suggested by an architect, change the
architect! if it is a problem in mathematics, suggested by your prof.
the procedure is available above. this can be found in any text book
on integration?
cicma (mechanical) (visitor)20 nov 00 11:48
autocad r14 can make you happy. just go to mass properties, define a boundary and that's it.you will have to browse the user's manual or another autocad book to know what you are doing. asme web site has a fea section where you could look into.

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