Using Pinching4 but the result is strange

Wenyu
Posts: 25
Joined: Sat Sep 10, 2022 2:58 am

Re: Using Pinching4 but the result is strange

Post by Wenyu » Tue Mar 21, 2023 2:51 pm

STKO Team wrote:
Tue Mar 21, 2023 8:51 am
You're welcome
Excuse me, I 'm asking again. The results of the time history analysis of the building model are not ideal, so I took a wall to load seismic waves on it. But I think there 's something wrong with my way of loading that makes the displacement-force curve strange. Can you help me?
Attachments
shearwall.rar
(105.55 KiB) Downloaded 31 times

ValentinaSB
Posts: 61
Joined: Thu Dec 09, 2021 10:53 am

Re: Using Pinching4 but the result is strange

Post by ValentinaSB » Wed Mar 22, 2023 9:32 am

Hi Wenyu,
You are applying fixity and prescribed displacement to the same node.
Screenshot 2023-03-22 093726.jpg
Screenshot 2023-03-22 093726.jpg (124.14 KiB) Viewed 1213 times
Do you have acceleration or displacement in your path timeseries?
Look also at your concrete material, it has a strange unloading path, probably your lambda is too small, try to calibrate the concrete.
Screenshot 2023-03-22 102807.jpg
Screenshot 2023-03-22 102807.jpg (95.26 KiB) Viewed 1213 times
You are performing a transient analysis, but you don't apply mass.

Best,
Valentina

Wenyu
Posts: 25
Joined: Sat Sep 10, 2022 2:58 am

Re: Using Pinching4 but the result is strange

Post by Wenyu » Fri Mar 24, 2023 8:02 am

ValentinaSB wrote:
Wed Mar 22, 2023 9:32 am
Hi Wenyu,
You are applying fixity and prescribed displacement to the same node.
Screenshot 2023-03-22 093726.jpg
Do you have acceleration or displacement in your path timeseries?
Look also at your concrete material, it has a strange unloading path, probably your lambda is too small, try to calibrate the concrete.
Screenshot 2023-03-22 102807.jpg
You are performing a transient analysis, but you don't apply mass.

Best,
Valentina
Yes i have acceleration in my path timeseries. I make some change on concrete material and i apply mass, but when i apply mass, the model not running. If i don't apply mass,whatever transient and static, use the uniformExcitation or prescribednodalvalue on the top node, the model is running but there is nothing on the result. It 's like no force was applied
Attachments
result.png
result.png (691.45 KiB) Viewed 1196 times

ValentinaSB
Posts: 61
Joined: Thu Dec 09, 2021 10:53 am

Re: Using Pinching4 but the result is strange

Post by ValentinaSB » Tue Mar 28, 2023 2:33 pm

Hi Wenyu,
Could you post your last version of the model and we will give a look at it?

Best,
Valentina

Wenyu
Posts: 25
Joined: Sat Sep 10, 2022 2:58 am

Re: Using Pinching4 but the result is strange

Post by Wenyu » Wed Mar 29, 2023 6:06 am

ValentinaSB wrote:
Tue Mar 28, 2023 2:33 pm
Hi Wenyu,
Could you post your last version of the model and we will give a look at it?

Best,
Valentina
Thanks for you reply, This is the last version, and there shows "could not invert flexibility", I have encountered this warning many times, but it is rarely resolved.
There is an overall model of the building structure, but "could not invert flexibility" occurs when the seismic wave is input after the first analysis step is completed.Also hope to get your help.
Attachments
building.rar
(168.03 KiB) Downloaded 32 times
shearwall.rar
(108.8 KiB) Downloaded 35 times
running.png
running.png (78.68 KiB) Viewed 1174 times

ValentinaSB
Posts: 61
Joined: Thu Dec 09, 2021 10:53 am

Re: Using Pinching4 but the result is strange

Post by ValentinaSB » Thu Mar 30, 2023 3:42 pm

Hi,
This error can be due to GJ, but I have checked that you have it in all sections. It can also be due to the failure of the material. Let's check first all your materials. Which units of measurement do you use for example for the building model? kN, m? Check for example steel01.
Screenshot 2023-03-30 173939.jpg
Screenshot 2023-03-30 173939.jpg (61.91 KiB) Viewed 1165 times
Also, check if the assignment of your properties is correct ( you can select the physical property from the tree and show only it, you will be able to see to which elements you assigned it) check for example the physical properties that you called "now".
Screenshot 2023-03-30 173354.jpg
Screenshot 2023-03-30 173354.jpg (100.65 KiB) Viewed 1165 times
Also, it can be helpful to simplify the model first, to make sure that it is working properly, and then already to add more steps. For example, try to run just vertical static analysis, and if the response is as you expected you can move to the transient one.

Best,
Valentina

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