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Valued Contributor
sergey.churilov
Posts: 60
Registered: ‎04-12-2012

Modelling wall panel with springs

275 Views, 6 Replies
04-17-2012 05:50 AM

Hi to all.

I am thinking about the possibility of modelling wall panels with a series of springs, as shown in the attached picture. The spring stiffness and behaviour should be nonlinear, i.e. elastic-plastic.The top and bottom beam shall be rigid.

Which solution do you propose? Compatible nodes maybe?

 

Regards!

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Rafal.Gaweda
Posts: 5,315
Registered: ‎04-26-2010

Re: Modelling wall panel with springs

04-17-2012 06:02 AM in reply to: sergey.churilov

Bars with releases in the middle ?



Rafal Gaweda
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Valued Contributor
sergey.churilov
Posts: 60
Registered: ‎04-12-2012

Re: Modelling wall panel with springs

04-17-2012 06:28 AM in reply to: Rafal.Gaweda

Hmm. I am attaching a file with the proposed concept. Many instability problems were found.

Can you please check the model?

I would like to define shear spring for the diagonal element, but also compression springs to vertical elements.

Is it possible to apply displacement time history in the top left node, instead of static force (in the example it is 100 kN)?

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Rafal.Gaweda
Posts: 5,315
Registered: ‎04-26-2010

Re: Modelling wall panel with springs

04-17-2012 07:21 AM in reply to: sergey.churilov

Hmm. I am attaching a file with the proposed concept. Many instability problems were found.

Can you please check the model?

I would like to define shear spring for the diagonal element, but also compression springs to vertical elements.

 

Should be like this now?

 

rel.jpg


Is it possible to apply displacement time history in the top left node, instead of static force (in the example it is 100 kN)?


See below

 

tha.jpg



Rafal Gaweda
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Valued Contributor
sergey.churilov
Posts: 60
Registered: ‎04-12-2012

Re: Modelling wall panel with springs

04-18-2012 12:12 AM in reply to: Rafal.Gaweda

Thank you Rafal.

Can you please send me your file. I am having troubles reproducing the model you suggested. I obtain zero displacements for the time history analysis.

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Rafal.Gaweda
Posts: 5,315
Registered: ‎04-26-2010

Re: Modelling wall panel with springs

04-18-2012 03:22 AM in reply to: sergey.churilov

This approach works for linear models.

For nonlinear:

- apply imposed diplacement in simple case, record reaction in this node

 

fxreac.jpg

 

- remove support and imposed displacement load, apply nodal load with reaction value, define THA with the settings as shown above

 

thadispl.jpg



Rafal Gaweda
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Rafal.Gaweda
Posts: 5,315
Registered: ‎04-26-2010

Re: Modelling wall panel with springs

04-18-2012 04:28 AM in reply to: Rafal.Gaweda

- apply imposed diplacement in simple case, record reaction in this node

- remove support and imposed displacement load, apply nodal load with reaction value, 

 


As usual I was too fast :-)

What is written above is correct for non-dynamic actions (statics).

Dynamic response from structure for loads excitation (dynamic excitation) and displacement excitation (kinematic excitation) is \ can be different.

So... In case of kinematic excitation robot presents "zero" displacement values in THA case results in the (supporting) node(s) where the imposed displacement is applied. Therefore the displacement diagrams are not correct.

All other results in this(these) node(s) are correct, and ALL results in other nodes are correct.

So in your case do not look at displacement results in node 2, do not look at deformation diagram

(PS support in node 2 must have blocked UX dof, my mistake with spring ; corrected model attached)

 

excit.jpg



Rafal Gaweda
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