Hello
I have an Important question about concentrated plastic hinge parameters setting:
In model with concentrated plastic hinge, the stiffness of spring modify by a "n" parameter (multiply by n) SO the rotation of the hinge
decrees n times. When I plot moment-rotation response of a hinge the yield rotation is obtained about 0.0007 rad (in my example) but the real value is 0.007 radian. I realize this happens because of modify the elastic stiffness of spring by "n"
my question is:
In setting plastic hinge parameters (pre capping plastic rotation and post capping plastic rotation and ...) Should we reduce the values obtained from the empirical relationships by n times (Lignos parameters) or replace the original values?
Search found 65 matches
- Thu Nov 18, 2021 11:13 am
- Forum: OpenSees.exe Users
- Topic: Concentrated Plastic Hinge calibration parameters
- Replies: 0
- Views: 11944
- Sat Nov 17, 2018 2:40 am
- Forum: OpenSees.exe Users
- Topic: pretensioned bar
- Replies: 0
- Views: 1445
pretensioned bar
hello
how can I make a pre-tensioned bar element that is fixed in ends
how can I make a pre-tensioned bar element that is fixed in ends
- Sat Nov 17, 2018 12:42 am
- Forum: OpenSees.exe Users
- Topic: Period of a portal frame
- Replies: 1
- Views: 1897
Period of a portal frame
Hello
I made a portal frame with elastic beam column element and concentrated plastic hinges at the ends of elements. then I analysed it with and without "equaldof" for tow nodes on the roof under earthquake record. when I use "equalDOF", period of the structure is about 0.6 sec and without it the period is 0.45 sec but the velocity history of the structure is same in tow ways. can any one explain me why?
I need to understand it because decreasing in period affects on viscus damping energy.
I made a portal frame with elastic beam column element and concentrated plastic hinges at the ends of elements. then I analysed it with and without "equaldof" for tow nodes on the roof under earthquake record. when I use "equalDOF", period of the structure is about 0.6 sec and without it the period is 0.45 sec but the velocity history of the structure is same in tow ways. can any one explain me why?
I need to understand it because decreasing in period affects on viscus damping energy.
- Fri Sep 14, 2018 1:11 am
- Forum: OpenSees.exe Users
- Topic: ProfileSPD
- Replies: 1
- Views: 2414
ProfileSPD
Hello
I make a portal frame with concentrate plastic hinge and also I use a rotational fraction damper in it. when I run the model for eigen Analysis follow comments appear :
Modified Ibarra-Medina-Krawinkler Model with Bilinear Hysteretic Response
ProfileSPDLinDirectSolver::solve() - aii < minDiagTol (i, aii): (14, 3.97904e-013)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
T1 = 2.1093169264622746 s
T2 = 2.1093169264622746 s
Are these comments "Error"?
Can anyone explain these comments for me?
I make a portal frame with concentrate plastic hinge and also I use a rotational fraction damper in it. when I run the model for eigen Analysis follow comments appear :
Modified Ibarra-Medina-Krawinkler Model with Bilinear Hysteretic Response
ProfileSPDLinDirectSolver::solve() - aii < minDiagTol (i, aii): (14, 3.97904e-013)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (18, 0)
T1 = 2.1093169264622746 s
T2 = 2.1093169264622746 s
Are these comments "Error"?
Can anyone explain these comments for me?
- Sat Oct 21, 2017 11:03 am
- Forum: OpenSees.exe Users
- Topic: Modified Ibarra-Krawinkler Parameters
- Replies: 8
- Views: 7135
Re: Modified Ibarra-Krawinkler Parameters
hi
Can I use Mr. Lignos's suggested formulas for other than RBS beams to adjust the columns plastic hinges? or there is another formulation for columns?
Can I use Mr. Lignos's suggested formulas for other than RBS beams to adjust the columns plastic hinges? or there is another formulation for columns?
- Fri Oct 20, 2017 8:52 am
- Forum: OpenSees.exe Users
- Topic: Modified Ibarra-Krawinkler Parameters
- Replies: 8
- Views: 7135
Modified Ibarra-Krawinkler Parameters
Hi
Based on example in your website about MRF with panelzone and description about uniaxialMaterial Bilin there is contradiction. in example is expressed for no deterioration Lambda must be a large number but in command manual section is expressed they must be zero...!
which one is correct؟
Based on example in your website about MRF with panelzone and description about uniaxialMaterial Bilin there is contradiction. in example is expressed for no deterioration Lambda must be a large number but in command manual section is expressed they must be zero...!
which one is correct؟
- Tue Nov 10, 2015 11:02 am
- Forum: OpenSees.exe Users
- Topic: gravity load in time history analysis
- Replies: 0
- Views: 2390
gravity load in time history analysis
Hello to all
I want to analyse a moment frame for design it by non linear time history analysis method. I model a leaning column also. witch gravity load combination should be used for applying in beams and leaning column? I confused by standards. For nonlinear seismic analyses, ASCE 7 specifies a gravity load combination of 1.0D + 0.5L but FEMA 356 determined 1.1*(DL+LL) should be considered.
please guide me
I want to analyse a moment frame for design it by non linear time history analysis method. I model a leaning column also. witch gravity load combination should be used for applying in beams and leaning column? I confused by standards. For nonlinear seismic analyses, ASCE 7 specifies a gravity load combination of 1.0D + 0.5L but FEMA 356 determined 1.1*(DL+LL) should be considered.
please guide me
- Sun Sep 27, 2015 12:29 pm
- Forum: OpenSees.exe Users
- Topic: Bilin Material
- Replies: 3
- Views: 3661
Re: Bilin Material
Hello
Do we need modify Lambda parameter by equation (lambda*(n+1)) for concentrated plastic hinge frame?
Do we need modify Lambda parameter by equation (lambda*(n+1)) for concentrated plastic hinge frame?
- Tue Sep 01, 2015 9:12 am
- Forum: OpenSees.exe Users
- Topic: MIK Parameters
- Replies: 0
- Views: 5780
MIK Parameters
Hello
How I can calculate appropriate value of Lambda_S,Lambda_C,Lambda_A, Lambda_K for Modified Ibarra Krawinkler material (for AISC W Section)?
How I can calculate appropriate value of Lambda_S,Lambda_C,Lambda_A, Lambda_K for Modified Ibarra Krawinkler material (for AISC W Section)?
- Mon Dec 29, 2014 11:46 pm
- Forum: OpenSees.exe Users
- Topic: Maximum Force in elastic beam column element
- Replies: 3
- Views: 3279
Maximum Force in elastic beam column element
Hello
Is there any way to record maximum forces (p v m) in the elastic beam column element.??
Is there any way to record maximum forces (p v m) in the elastic beam column element.??
- Sat Nov 29, 2014 7:33 pm
- Forum: OpenSees.exe Users
- Topic: Concentric Plastic Hinges
- Replies: 1
- Views: 2003
Concentric Plastic Hinges
Hi
I Want to use rotational springs for plastic hinges with bilin material based on Ibarra-Krawinkler model.
for modifying stiffness of springs in the Ibarra& Krawinkler report (2005) bellow equation is provided.
1/Kmem=(1/Ks) + (1/Kbc) & Ks=n*Kbc ------> Ks=(n+1)*Kmem
so my question is:
is "Ks" stiffness of tow springs in a element ends or stiffness of each springs?
I think for a series of tow springs and a elastic beam column element for modeling a member, the resultant stiffness of assembly is:
1/Kmem= (1/Ks)+(1/Ks)+(1/Kbc)
I Want to use rotational springs for plastic hinges with bilin material based on Ibarra-Krawinkler model.
for modifying stiffness of springs in the Ibarra& Krawinkler report (2005) bellow equation is provided.
1/Kmem=(1/Ks) + (1/Kbc) & Ks=n*Kbc ------> Ks=(n+1)*Kmem
so my question is:
is "Ks" stiffness of tow springs in a element ends or stiffness of each springs?
I think for a series of tow springs and a elastic beam column element for modeling a member, the resultant stiffness of assembly is:
1/Kmem= (1/Ks)+(1/Ks)+(1/Kbc)
- Tue Nov 11, 2014 4:10 am
- Forum: OpenSees.exe Users
- Topic: leaning column effect
- Replies: 2
- Views: 2616
Re: leaning column effect
I use the model of 1 bay 2 story concentric moment frame in your website that written by "Laura Eads, Stanford University, 2010" for learning. in its attached word file is written that the period of the first and second mode is 0.81 and 0.18 respectively but when I run the file in opensees i see the period is very different (0.0098 & 0.0097). in the other hand when i remove leaning column from the original model the period is the same attached file!!!!!!!
my question is
is the model incorrect or the leaning column is affected the model? is normal the effect of leaning column on period of structure?
my question is
is the model incorrect or the leaning column is affected the model? is normal the effect of leaning column on period of structure?
- Mon Nov 10, 2014 12:03 pm
- Forum: OpenSees.exe Users
- Topic: leaning column effect
- Replies: 2
- Views: 2616
leaning column effect
is there any effect of leaning column on period of structure?
in my model, period is different with and without leaning column. is it normal?
in my model, period is different with and without leaning column. is it normal?
- Mon Nov 10, 2014 1:38 am
- Forum: OpenSees.exe Users
- Topic: leaning column loading
- Replies: 5
- Views: 6106
Re: leaning column loading
is there any effect of p-delta column (leaning column) on stiffness of a frame?
In my model, period of frame is different with and without p-delta column. is it normal?
In my model, period of frame is different with and without p-delta column. is it normal?
- Wed Oct 29, 2014 11:49 am
- Forum: OpenSees.exe Users
- Topic: leaning column loading
- Replies: 5
- Views: 6106
leaning column loading
Hi
in my model there is p-delta column and if "P" be total Load "(Dl+LL)*$WBuilding" on each Roof so my question is:
what is the load that must be applied to leaning column at each floor?
please explain
in my model there is p-delta column and if "P" be total Load "(Dl+LL)*$WBuilding" on each Roof so my question is:
what is the load that must be applied to leaning column at each floor?
please explain