gap material

Forum for OpenSees users to post questions, comments, etc. on the use of the OpenSees interpreter, OpenSees.exe

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civilso
Posts: 35
Joined: Mon Oct 25, 2010 1:37 pm
Location: mohaghegh ardabili university

Re: gap material

Post by civilso »

In case you have a material with a kink (ElasticPPGap) you can not use load command to apply the load as it will not be able to get you into nonlinear range for that material because of the kink.

this is about displacement control?
do you have any suggestion about kink?

i continue with opensees or use from another nonlinear analyze software?
vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: gap material

Post by vesna »

Yes, that is about displacement control.
There is no way remove the kink from ElasticPPGap material. That is a way it is defined.
civilso
Posts: 35
Joined: Mon Oct 25, 2010 1:37 pm
Location: mohaghegh ardabili university

Re: gap material

Post by civilso »

>That is a way it is defined.
how can i define it in opensees???
vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: gap material

Post by vesna »

opensees is an open source computation platform. you can develop your own material and add it to opensees.
civilso
Posts: 35
Joined: Mon Oct 25, 2010 1:37 pm
Location: mohaghegh ardabili university

Re: gap material

Post by civilso »

would you please tell me some suggestions or some helps or some sources to define kink and add other material to opensees?
civilso
Posts: 35
Joined: Mon Oct 25, 2010 1:37 pm
Location: mohaghegh ardabili university

Re: gap material

Post by civilso »

would you please tell me some suggestions or some helps or some sources to define kink and add other material to opensees?
vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: gap material

Post by vesna »

When I say kink I mean sharp transition from elastic to plastic region that characterizes all elastic perfectly plastic (EPP) materials. For EPP materials it is predefined.

Here you can find more information on how to develop and add new material to OpenSees:
http://opensees.berkeley.edu/OpenSees/d ... /index.php
abazarnejad
Posts: 6
Joined: Sat May 28, 2011 11:24 pm
Location: Shiraz University

Re: gap material

Post by abazarnejad »

check your fix points and fix directions you assigned!
abazarnejad
Posts: 6
Joined: Sat May 28, 2011 11:24 pm
Location: Shiraz University

stressStrain in Concrete04???

Post by abazarnejad »

Hi Dears
I need to capture stressStrain in my model(using concrete04 and steel02) but the results for concrete stress-strain is full of zeros "0".
I used this command:

recorder Element -file Data/stressstrainC.txt -ele 1 section 1 fiber 170 120 3 stressStrain;

recorder Element -file Data/stressstrainC.txt -ele 1 section 1 fiber $X $Y $MatID stressStrain;

AnyBody can Help Please!!
vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: gap material

Post by vesna »

This means that you are applying a load of zero for each time step. Make sure you have defined your load and analysis objects correctly.
mnazari
Posts: 29
Joined: Wed Aug 15, 2012 11:28 am
Location: ISU

Re: gap material

Post by mnazari »

Hi,
I have a quick question about gap material:
I have a prestressed rocking shear wall. If I want to model the rocking interface with only compression springs, is this command "uniaxialMaterial ElasticPPGap $matTag $E $Fy $gap <$eta> <damage>" exact enough to express all the compressive strains and possible damage in the concrete wall toe? Since we just need to define Fy value here and eta, which I am not sure how exactly is able to model the concrete.
Many Thanks
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