problem with ElastomericBearing element

[omalvarez]

Hi dear all, I hope someone can help me about a little problem with elastomericBearing element. I want to model elastomeric bearing like “link” element at SAP2000, I have used elastomericBearing element, but when I run a gravity analysis I get large values of moments around y-axis (the moments around x-axis and z-axis are close to zero). I have the next code:

#node tag x y z
node 356 0 -4.55 11.5
node 364 0 -4.55 11.55

uniaxialMaterial Elastic 1 1585.394 0

uniaxialMaterial Elastic 2 1E+10 0

Element elastomericBearing 38 356 364 286.8 1E+9 0 -P 1 -T 2 -My 2 -Mz 2 -orient 1 0 0 -mass 0

I need that elastomeric bearings do not work under bending. I have tried with ZeroLength Element, but I got the same results.
Best regards.

[maksins]

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 1 0 1 0 0 -mass 0

[omalvarez]

Hi maksins, I am using OpenSees Navigator, I can't orient the ElastomericBearing elements (or at least I don't know how to so), but instead of using a material with a high modulus of elasticity, I used a material with modulus of elasticity equal to zero and I assigned to it: T, My and Mz degrees of freedom and my model worked