How to connect a nonlinear spring with gap element?

[ismailqeshta]

Hi,

I am trying to model the abutment of a bridge.

I have seen in a study that the expansion joint and backfill soil are modeled by nonlinear spring connected with gap elements?

Does anyone have any idea on how that is done?

Thank you.


It has been done in this study (it can be found in Figure 3.3, Page 13):
Omrani, R., Mobasher, B., Liang, X., Gunay, S., Mosalam, K. M., Zareian, F., & Taciroglu, E. (2015). Guidelines for nonlinear seismic analysis of ordinary bridges: Version 2.0. Caltrans Final Report No. 15-65A0454. Link: https://www.researchgate.net/publicatio ... Version_20

[Prafullamalla]

Spring is formed by using zero length element and the material properties is assigned on it using suitable materials like steel02 with load-displacement relation instead of stress-strain.

to model a gap element how about using zero-length element with uniaxial elastic material

[Prafullamalla]

Check this hyperbolic gap material
http://opensees.berkeley.edu/wiki/index ... p_Material
http://opensees.berkeley.edu/community/ ... lic#p95208

[selimgunay]

It is done by connecting an ENT material with ElasticPPGap in parallel

[ismailqeshta]

Hi Selim,

Many thanks for your reply.

Would it be possible to explain why it has to be in parallel, not series?

I think you did it in series in your study (Omrani et al., 2015) cited in my post above.

[selimgunay]

I meant together actually, so series should be fine if it is cited like that

[ismailqeshta]

Hi Selim,

When I assign Elastic-no Tension (ENT) material in parallel with another material, I find that it does not work.

For example:
uniaxialMaterial Elastic 3 100.0
uniaxialMaterial ENT 4 0.00000001
uniaxialMaterial Parallel 1 3 4


The above would work in both tension and compression. It should not work in tension due to the existence of ENT.


Would it be possible to ask if you can clarify further on this?

Thank you.

[hosnieh]

hi
I want to add a gap element at the base of a column of the first story, I modeled beam and column with elasticbeamcolumn and rotational springs at the ends. I need help about connection of rotational spring of nonlinear behaviour of column and linear spring for gap.
plz help me