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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 an...

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 ...

The section deformations are just that, the deformations that the section can experience. If you're using a fiber section, this is typically axial strain, curvature in the z-direction and curvature in the y-direction. If you've used a section aggregator to add more force-deformation relationships to...

I haven't tried this before but I imagine it goes like this: Create a sinusoidal time series with the timeSeries Trig option. timeSeries Trig $tag $tStart $tEnd $period <-factor $cFactor> <-shift $shift> Then create a plain load pattern using the timeSeries tag from above. pattern Plain $patternTag ...

Your cases are redundant and two cases are not even possible because OpenSees employs the right-hand rule to determine local orientation. Consider an element in the 3D case: The local x direction corresponds to the line connecting the two endpoints of the element; The local z direction is defined by...

While I haven't personally been through the following links in much detail, I would expect they would be good primers to get started: http://opensees.berkeley.edu/wiki/index.php/Getting_Started http://opensees.berkeley.edu/wiki/index.php/Basic_Examples_Manual OpenSees is such a versatile tool that i...

Will do, I've been playing around with existing tcl commands to pull the time for a given block to run. I was mostly interested if there was any overhead involved when the analyze command gets called (much like how the CPU has to save an address when a function is called in typical programming). I'l...

Say I build a model and call the analyze command once for at each time step (contained within a while loop; i.e. set ok [analyze 1 $dt]) as opposed to doing it all at once (i.e. set ok [analyze $numSteps $dt]). Assuming everything converges and no other commands are contained within the while loop, ...

It's very possible that you encountered roundoff error associated with machine computing. When numbers get very large or very small, the computer will keep a specified number of significant digits and toss out anything behind it, which would very well cause convergence issues.

"basicdeformation" is the deformation of the element in it's basic coordinates. Basic coordinates track an elements change in length (along a chord that is a straight line between its two endpoints) and the rotations at each endpoint. The recorder will report these three values. These deformations a...

I saw that in some of your other posts. Thank you for the suggestion. I'll have to do some testing to make sure it works as intended in my abutment model (I also have several other zeroLength springs for modelling soil).

linguan, Your load factor is very large from the first error message you reported. I'm assuming you're using the displacement control method. I had a similar problem in one of my models which was a result of forgetting to redefine a load pattern after setting the axial load constant. If this is also...

Much appreciated, thank you for the response.

Quick thoughts.... 1) In general, the force-based beamColumn elements should work. If they don't, it's generally because of a problem with your section definition (I would check your fibers are being defined correctly). Since force-based elements use internal iterations to enforce compatibility, you...

I'm looking to add friction to my model between the bridge superstructure and the abutments on which the deck rests. I was planning on using the zeroLengthContact element to do this but it complained that I had too many DOF's at the node in question. The wiki states, "For 2D contact, slave nodes and...