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Can someone please provide the formulation details of singleFPbearing element in OpenSees,

In the Opensees site there are no references to the formulation.

Accord to the website :

Image with the circle of FY/Fx and FZ/FX is given, Limit is given as the coefficient of friction. Along with the same image there is FY/FX or FZ/FX versus dy or dz graph is given, In the graph, the ratio crosses the value of the coefficient of friction but circle with radius coefficient of friction is given in former image.

How can I give the input displacement capacity of bearing?
What are the criteria for bearings to fail in this formulation?

In my model this won't be a problem as mine is not a single DOF, I changed some material properties and the error disappeared.

Hi
I am doing eigen analysis on building with bearings, for bearings i am using ElastomericBearingBoucWen element
when i did eigen analysis i am getting the error as below

ArpackSolver::Error with _saupd info = -9999
Could not build an Arnoldi factorization.IPARAM(5) the size of the current Arnoldi factorization: is 1factorization. The user is advised to check thatenough workspace and array storage has been allocated.
WARNING DirectIntegrationAnalysis::eigen() - EigenSOE failed in solve()

What does this error means, I checked connectivity of my nodes every node is connected and model is constrained properly.

Did you solve this issue?
Even I am getting the negative eigen value when 3d frame is isolated with LRB isoator?

Can I use Layered shell elements for modelling the dome structures?
I need to model Reinforced concrete dome structure, can someone suggest me the element type?

Dear selimgunay
I will check with above.

I have new problem of non-convergence during IDA. I am using lumped plasticity model when I do the the dynamic analysis there is convergence problem, so I increased the tolerance (initially it was 1 e-8) to 1e -4 ,it is working without convergence problem. I wanted to know whether there is effect of tolerance limit on solution. If yes, then What is max tolerance limit recommended for dynamic analysis?

I am new to OpenSees. I am using Concrete07 material, for specifying the properties of concrete07 material model I found formulae from the below site
https://opensees.berkeley.edu/OpenSees/ ... l/4055.htm
when I compare the values for ec0(maximum compressive strain) for US cutomary units and the SI units there is difference the formula when fc is in Psi
is (fc0)^(1/4)/4000 and for MPa the formula is (fc0)^(1/4)/28
when I take 24 MPa(3480 Psi) concrete
I get eco as 0.0079 from SI unit formula and 0.00192 from Psi formula
fmk Can you please tell whether the formulae in the site are correct.
P.S when I use the -0.00192 gravity analysis is failing

Hi frank,
I had model building frame using fibre distributed element model,I used the NonlinearBeamColumn element for this ,I had followed the example7(3D FRAME) given in OpenSees website,i changed units to SI and material properties.When I increase the number of fibres in core concrete patch (initially it was 20,i had made to 200)the eigen values are becoming negative.The same problem repeats when I change the NonlinearBeamColumn element to DispBeamColumn element.Can you please tell where I am going wrong?
I can mail the model file if required.
Thank You

Hi everyone,
I am working on seismic vulnerability assessment of buildings.I need to model a RC building for Incremental dynamic analysis in order to get fragility curves.I have read the research papers on this analysis.In all papers they are doing the IDA on lumped plasticity structure model using some hysteretic models.can we do IDA on fiber distributed structural models?

Regards
Bhagyasree