1 Topic by umgouda (edited by umgouda 2014-02-26 05:55:18)

  • Registered: 2014-02-26
  • Posts: 3

Topic: Uplifting for the corners of the slab in concrete slab-column model

Hi,
I am having some difficulties to choose a support that could reflect the actual behavior of my model. In general, my model consists of a slab which is simply supported at the edges and there is a column stub extended on the top and the bottom of the center of the slab. I am applying the loads on the  column stubs. My problem is that, the corners of the slab are moving upward at a load of approximately between 90% to 95% of the ultimate load. So, I need supports for the corners or interface element between the supports and the corners of the slab that prevent the corners of the slab from moving downward and allow for the upward movement. How can I do that in ATENA?

Quote Post 1

  • dpryl
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Re: Uplifting for the corners of the slab in concrete slab-column model

Hello, the easiest way is probably a nonlinear spring support in vertical direction, with stiffness in compressive direction about 100-1000 higher than in tension.

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Quote Post 2

  • Registered: 2014-02-26
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Re: Uplifting for the corners of the slab in concrete slab-column model

Is there any other way?

Quote Post 3

  • dpryl
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Re: Uplifting for the corners of the slab in concrete slab-column model

There are other ways, but, as already mentioned, more complicated. For example, you can model elastic plates at the supports, and use Interface elements for the contact between the elastic plate and the concrete. Compared to the springs, you have more elements, and, even worse, more parameters to determine/guess...

Is there any specific reason why you do not like to use spring supports?

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Quote Post 4

5 Reply by umgouda (edited by umgouda 2014-03-04 00:01:31)

  • Registered: 2014-02-26
  • Posts: 3

Re: Uplifting for the corners of the slab in concrete slab-column model

Yes, actually the corners instead of moving up, they are moving down. So, can you please tell me another way. Or, for the method you described (elastic plate), can you please give me a source describing how to model it in ATENA, so I can look at it.

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  • dpryl
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Re: Uplifting for the corners of the slab in concrete slab-column model

It is normal that the upward movement of the corners can only be observed relative to other parts of your structure (especially if the spring compressive stiffness is relatively low). Moreover, this is the same with interface elements, just there are more parameters which can be set wrongly or in an inconsistent combination.

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Quote Post 6