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Use tag5 = 0 (default value)

If you are using the example file from SVN repository, it is intended to be used with the upcoming version of OpenSees (2.4.6 ?). Parameter arguments are different and there are minor bug fixes as well. You either build OpenSees on your computer with the latest revision and use the current example f...

Very nice discussion! I would also like to add that (it might already be obvious to many people), when using Rayleigh or Stiffness proportional damping, the option for element's contribution to rayleigh damping (due to element's mass and stiffness) must be turned on (i.e., doRayleigh must be 1), oth...

Thanks Matthew,
I was not aware of all of them. Please do post if you discover additional features.

In the first case you are performing the static analysis in one step. The tangent stiffness at the beginning of the analysis is used. In the second case, you are performing analysis in 10 steps, the tangent stiffness at the beginning of each step that is closer to the instantaneous tangent stiffness...

What I understand is that when you decrease your time step, you increase the resolution and hence the maximum frequency that you can capture in your response. Since your shear force is dependent on the axial force, you capture high frequency oscillations when you decrease the time-step. If you remov...

Thanks Frank, I did what you suggested and I am able to proceed with my analysis. However, I was wondering if there was a way to return a specific error value, for example -7, to know if it fails due to buckling and not due to other solution algorithm convergence problems? Also, then I won't have to...

It's because bearings are very flexible in the rotational direction, zero resistance in torsion. Although I don't know assigning zero would create any problem in inversion of stiffness matrix. I would assign very small values.

For some elements in OpenSees (bearing elements), when the failure is encountered, the program crashes due to command exit(-1). This is fine for a single analysis, but when I am running multiple analysis in a loop, it creates me prolem. I was wondering if there's an alternative of exit(-1) command I...

It might be related to ill-conditioned matrix due to very high values of stiffness you are providing in axial and moment direction. Usually, an elastomeric bearing would have vertical stiffness that 100-500 times the horizontal stiffness. So use 500000 for vertical stiffness (you can actually determ...

Hi Frank,
should it be Vz = Vy X Vx, or Vz = Vx X Vy?
The local axes shown in last image shown of the transformation page (http://opensees.berkeley.edu/wiki/index ... sformation) is according to Vz = Vx X Vy (right-hand rule).
Please let me know if I am misinterpreting something?

Few suggestions as to when to use elastomericBearing element or LeadRubberX: If you want to use your own material model to model a lead rubber bearing use elastomericBearing element. It will provide you flexibility to use any material model you want in axial and rotational directions, and also abili...

Hi Frank, My element is elastic, and I want to assign different shear areas (Ay and Az) at a particular section, not along the length of the element. The shear properties are constant along the length. It is basically to simulate eccentricity in the stick model of a nuclear reactor. Can I use "...

You have oriented your local x-axis to be along global X-axis. However in an elastomeric bearing, local x-axis is usually along global Y-axis (considering vertical orientation). Try this, and let me know if it works: Element elastomericBearing 38 356 364 286.8 1E+9 0 -P 1 -T 2 -My 2 -Mz 2 -orient 0 ...

I need to create a beam element with different shear areas of the section in the two directions. Any suggestions?