Zerolength and Twonodelink

[UnileGianni]

Hi everyone,
I need to compare results obtained by using twonodelink and zerolength elements. I used at first zerolength elements and then twonodelink elements to model flexural hinges in columns assuming the same uniaxial pinching4 material for both the elements. Can you tell me why the results obtained from dynamic analysis are different? I'll show only the differences between the model with twonodelink and the one with zerolength elements because the second one correctly works. Materials 160 and 161 are previously defined but in my opinion it doesn't matter because I used equalDOFs to inhibit x and y displacements of the nodes.

1) MODEL 1

node 1 0.0 0.0
node 2 0.0 0.4
node 3 0.0 0.4
node 4 0.0 0.563
node 7 0.0 2.836
node 8 0.0 3.0
node 9 0.0 3.0
node 10 0.0 3.4
node 11 4.5 0.0
node 12 4.5 0.4
node 13 4.5 0.4
node 14 4.5 0.563
node 15 4.5 2.836
node 16 4.5 3.0
node 17 4.5 3.0
node 18 4.5 3.4

section Uniaxial 9 9 Mz

element zeroLengthSection 213 2 3 9
element zeroLengthSection 214 8 9 9
element zeroLengthSection 215 12 13 9
element zeroLengthSection 216 16 17 9

equalDOF 2 3 1 2
equalDOF 8 9 1 2
equalDOF 12 13 1 2
equalDOF 16 17 1 2

2) MODEL 2

node 1 0.0 0.0
node 2 0.0 0.4
node 3 0.0 0.4
node 4 0.0 0.563
node 7 0.0 2.836
node 8 0.0 3.0
node 9 0.0 3.0
node 10 0.0 3.4
node 11 4.5 0.0
node 12 4.5 0.4
node 13 4.5 0.4
node 14 4.5 0.563
node 15 4.5 2.836
node 16 4.5 3.0
node 17 4.5 3.0
node 18 4.5 3.4

element twoNodeLink 213 2 3 -mat 161 160 9 -dir 1 2 3
element twoNodeLink 214 8 9 -mat 161 160 9 -dir 1 2 3
element twoNodeLink 215 12 13 -mat 161 160 9 -dir 1 2 3
element twoNodeLink 216 16 17 -mat 161 160 9 -dir 1 2 3

equalDOF 2 3 1 2
equalDOF 8 9 1 2
equalDOF 12 13 1 2
equalDOF 16 17 1 2

[saeedjafari]

Hi
I have modeled a TMD in a 5 story 3D RC structure and I have carried out a Time history analysis of it. But the displacements are the same when there is no TMD. I will write down it's part of my scripts. Please helllllp me. thanks

# 5thstory

node 61 0. 17.5 0.
node 62 4. 17.5 0.
node 63 8. 17.5 0.
node 64 12. 17.5 0.

node 65 0. 17.5 5.
node 66 4. 17.5 5.
node 67 8. 17.5 5.
node 68 12. 17.5 5.

node 69 0. 17.5 10.
node 70 4. 17.5 10.
node 71 8. 17.5 10.
node 72 12. 17.5 10.

# Master nodes for TMD
node 82 4. 17.5 5.
node 83 4. 17.5 5.

equalDOF 66 82 1 2 4 5 6
equalDOF 66 83 2 3 4 5 6

uniaxialMaterial Elastic 4 173672604.0
element zeroLength 405 66 82 -mat 4 -dir 3 3
element zeroLength 406 66 83 -mat 4 -dir 1 1

*******
What is wrong with that????

[mkcivilsepehr]

Dear Saeed
I have the same problem
Could you please tell me how you solve it?