Search found 41 matches

by luckypants
Sat Oct 24, 2020 2:47 pm
Forum: Analysis
Topic: Seven-story structure (convergence problem)
Replies: 0
Views: 96

Seven-story structure (convergence problem)

Dear STKO Team: I tried to build the seven-story structure with plastic hinges. However, there was the convergence problem in my model. I couldn't get the result. I also built the same model in ETABS to check the result. I found the ground motion caused structural damage and permanent displacement t...
by luckypants
Wed Oct 21, 2020 3:35 pm
Forum: OpenSees Sequential
Topic: How to consider the rotational mass in linear elastic static analysis?
Replies: 9
Views: 141

Re: How to consider the rotational mass in linear elastic static analysis?

Dear STKO Team: Yes, I have done what you said. I put their sum as translational masses at the Center of Mass of that floor and add the rotational contribute (MRZ). I have done some linear elastic static analysis in ETABS. One case(Diaphragm) was that all the floor was assigned the rigid diaphragm, ...
by luckypants
Tue Oct 20, 2020 2:52 pm
Forum: OpenSees Sequential
Topic: How to consider the rotational mass in linear elastic static analysis?
Replies: 9
Views: 141

Re: How to consider the rotational mass in linear elastic static analysis?

Dear STKO Team: Because I wanted to match the result of ETABS, I did the same in ETABS.(You could see the following picture) Now, I know how to calculate MRZ of rigid diaphragm(1F~RF). But I don't know how to calculate if there isn't rigid diaphragm(GF). How should I calculate rotational masses of G...
by luckypants
Tue Oct 20, 2020 2:16 pm
Forum: OpenSees Sequential
Topic: How to consider the rotational mass in linear elastic static analysis?
Replies: 9
Views: 141

Re: How to consider the rotational mass in linear elastic static analysis?

Dear STKO Team: Thank you for your reply. Then, I still want to ask some questions. I did the linear elastic static analysis, and I found something weird. I deleted the rotational mass in the floor's master node because you said the rotational effect arise naturally in the eigenvalue analysis due to...
by luckypants
Tue Oct 20, 2020 7:02 am
Forum: OpenSees Sequential
Topic: How to consider the rotational mass in linear elastic static analysis?
Replies: 9
Views: 141

Re: How to consider the rotational mass in linear elastic static analysis?

Dear STKO Team: Thank you for your reply. I reorganize my question. I consider rigid floor in 1F~RF. So I set rigid diaphragm in each floor except for ground floor(GF), and I also input MRZ in the floor master node. Now, there are some problems. Because there are no floor in GF, I don't set rigid di...
by luckypants
Mon Oct 19, 2020 2:39 pm
Forum: OpenSees Sequential
Topic: How to consider the rotational mass in linear elastic static analysis?
Replies: 9
Views: 141

How to consider the rotational mass in linear elastic static analysis?

Dear STKO Team: I did the linear elastic static analysis both in ETABS and STKO, because I want to compare the results and also check the 7-story model I built in STKO is right. I separately input the same ground motion in two directions(X and Y). Then, I found the result of roof displacement(I choo...
by luckypants
Mon Oct 19, 2020 12:18 pm
Forum: Geometry
Topic: Question about elastic shell element
Replies: 8
Views: 282

Re: Question about elastic shell element

Dear STKO Team:

I see. Thank you very much. :D :D

Best Regards
by luckypants
Sun Oct 18, 2020 9:42 am
Forum: Geometry
Topic: Question about elastic shell element
Replies: 8
Views: 282

Re: Question about elastic shell element

Dear STKO Team: I solve my problem. Thank you very much. Then, there are two question I want to ask. 1. What do "scaleDrilling" and "updateBasis" mean? I don't see the explanation in OpenSees manual. 2. I did the modal analysis to compare the coarse mesh (one element per wall) with fine mesh (used t...
by luckypants
Tue Oct 13, 2020 4:16 pm
Forum: Geometry
Topic: Question about elastic shell element
Replies: 8
Views: 282

Re: Question about elastic shell element

Dear STKO Team: I see. Now, there is another problem I want to ask. Will the result be weird if I don't refine my mesh for shells(I still use one element per wall)? Could it influence the result of the analysis if I use a coarse mesh(one element per wall)? Then, the following is my model. Could you ...
by luckypants
Mon Oct 12, 2020 12:56 pm
Forum: Geometry
Topic: Question about elastic shell element
Replies: 8
Views: 282

Re: Question about elastic shell element

Dear STKO Team: Thank you very much. I follow your steps to revise the model, and it works now. But there is still the problem in my model. After I finish the modal analysis, the result is weird. Does using 1 element per wall cause the error? How could I refine my mesh? How could I solve the problem...