Dear SEiMOSOFT Team
i have been modeling a 4 story X-braced building and apart from not being sure whether or not i have modeled the braces correctly,after i run IDA analysis time-history loading is not appled to the structure ,since real time plotting does not show any of it.
Please have a look on model let me know if i did anything wrong.
http://wikisend.com/download/263208/1st.spf
PS :tnx a lot for your reply on knee bracing.i was wondering if you have any sample X-braced & Knee-Brace model since there isn't any on the verification Models.
Really Appreciated
BeHNam
Not Considering Time-History Loading
Re: Not Considering Time-History Loading
BeHNam, I notice a few problems which you should address in your model:
1.Your dynamic loadings were applied as type "Force" instead of type "Acceleration". So your applied dynamic load was simply small forces at the supported nodes.
2. I wonder if you section properties are too small by a factor of 10? For example a typical flange width is 0.055 meters. Are you sure this should not be 0.55 meters?
3. You have no mass applied other than the bare frame mass derived from the elements. You should add the floor weights as concentrated lumped mass elements.
4. Your time histories applied in perpendicular directions have different time steps. Perhaps this is no problem internally for SeismoStruct, but it is unusual.
5. The end of your loading stage is at 20 seconds, whereas your longer duration record goes out to 39.88 seconds.
6. The time step in your loading stages exceeds the time step in the accelerograms. This is not good practice and is prone to erroneous results.
These changes should get you to a good starting point to start evaluating and tweaking your model.
1.Your dynamic loadings were applied as type "Force" instead of type "Acceleration". So your applied dynamic load was simply small forces at the supported nodes.
2. I wonder if you section properties are too small by a factor of 10? For example a typical flange width is 0.055 meters. Are you sure this should not be 0.55 meters?
3. You have no mass applied other than the bare frame mass derived from the elements. You should add the floor weights as concentrated lumped mass elements.
4. Your time histories applied in perpendicular directions have different time steps. Perhaps this is no problem internally for SeismoStruct, but it is unusual.
5. The end of your loading stage is at 20 seconds, whereas your longer duration record goes out to 39.88 seconds.
6. The time step in your loading stages exceeds the time step in the accelerograms. This is not good practice and is prone to erroneous results.
These changes should get you to a good starting point to start evaluating and tweaking your model.
Tim Huff
Re: Not Considering Time-History Loading
Thanks a lot for your quick reply.
regarding no.1 i did what i had seen in the video tutorial,but you're right.
Also the sections are the ones from symmetric I from software.
I will do the changes .
Thanks again
regarding no.1 i did what i had seen in the video tutorial,but you're right.
Also the sections are the ones from symmetric I from software.
I will do the changes .
Thanks again
-
seismosoft
- Posts: 1271
- Joined: 06 Jul 2007, 04:55
Re: Not Considering Time-History Loading
Dear Behnam,
You are right. By mistake the video tutorial was wrong, we already fixed the problem.
Thanks for the notice and apologies for this inconvenience.
Regards,
Seismosoft Support
You are right. By mistake the video tutorial was wrong, we already fixed the problem.
Thanks for the notice and apologies for this inconvenience.
Regards,
Seismosoft Support