Question on Circular Layer Command

[fbeckwit]

I have a quick question on the "layer circ" command regarding the optional start & end angles. Here is the command directly from the wiki:

# layer circ $matTag $numFiber $areaFiber $yCenter $zCenter $radius <$startAng $endAng>

Does the $endAng need to be larger than the $startAng? For example, if I specify a circular layer like this...

layer circ $steelTag 20 1.56 0.0 -16.5 28.17 150.0 30.0; #Angle range between 150° to 30° (390°);

... will it cause a problem in generating the fibers? The reason for this question is I'm modeling an oblong bridge column with intersection reinforcement cages. I have #11 bars on the outside of the entire cage while #8 bars are present in the intersection of the cage. I need to be able to specify the angle of the bottom cage beginning at 150° (as in this example) so that the two outside cages aren't spilling into each other.

On a similar note, do the angles have to specified always greater or equal to 0.0? On the same token as above, I would call the other circular section to range between -30° (330°) and 210°.

Thanks in advance!

[fmk]

why don't you try it out and see! if it causes problems, you can generate provide a simple tcl procedure which will generate the fibers. call this procedure inside your section command

http://opensees.berkeley.edu/wiki/index ... er_Section
http://opensees.berkeley.edu/wiki/index ... er_Command

[fbeckwit]

Well I have the section built but the entire structure I'm modeling has a first period of 4.5 seconds and I'm skeptical that the result is correct. I suspect there might be issues with the column (I've yet to run my pushover though). I'll write a procedure of my own to place the individual fibers and see if it gives different results.

[fmk]

you could always check the period of a single column.