oswaldorussian
Structural
- Oct 13, 2015
- 2
Hello all,
I am trying to create a model for a Wharf where the Axial Load-Displacement relationship of the Steel Piles is defines using a Multilinear Plastic (Kinematic) Link. The Load-Displacement relationships I have found through Non-linear Buckling Analysis of the piles.
We have 140 Piles and 140 Load-Displacement relationships in an Excel file, so we want to input them using the OAPI. All the piles show a softening behavior or 'negative slope' after peak load, which is of some concern to us. However, I have done a simulation manually entering the following Load-Displacement Relationship, and the program accepted it and provided good results. Here the P vs. D information:
D (in) P (kip)
-5.00 -20.66
-0.75 -20.66
-0.10 -43.36
-0.09 -46.89
0.00 0.00
0.01 4.00
0.75 5.00
The first two values indicate a 'remaining capacity' of the pile after buckling of 20.66 kips. The capacity of the pile in compression is 46.89 kips. Since we don't have information for the behavior in tension, we just input some nominal values for the positive deformation branch.
If I input this non-linear relationship for the multilinear link manually, the program accepts it and runs without problems.
However, if I input it through the OAPI, it creates the multilinear link property and assigns it successfully, but it just gives the default Load-Displacement relationship.
I know the code is working because if I use a Load-Displacement relationship like the ones in the verification examples, say:
D (in) P (kip)
-16 -55
-6 -50
-1 -40
0 0
2 50
6 70
16 80
...my code is able to correctly input the Load-Displacement relationship. Note that there are no negative slopes here.
Now, I am sorry for the long-winded description of my problem, but it would be most helpful to hear your impressions on this, ideas on why the OAPI would have problems inputting the same values that I am able to input manually, or alternatives to my general approach.
***As an aside, does anyone know what type of code goes into the "order rows" button in the multilinear plastic link nonlinear relationship section, and how to implement it through the OAPI? I feel this might be helpful as well.
Again, I am most thankful and look forward to hearing from you.
Kind regards,
Oswaldo Russian
I am trying to create a model for a Wharf where the Axial Load-Displacement relationship of the Steel Piles is defines using a Multilinear Plastic (Kinematic) Link. The Load-Displacement relationships I have found through Non-linear Buckling Analysis of the piles.
We have 140 Piles and 140 Load-Displacement relationships in an Excel file, so we want to input them using the OAPI. All the piles show a softening behavior or 'negative slope' after peak load, which is of some concern to us. However, I have done a simulation manually entering the following Load-Displacement Relationship, and the program accepted it and provided good results. Here the P vs. D information:
D (in) P (kip)
-5.00 -20.66
-0.75 -20.66
-0.10 -43.36
-0.09 -46.89
0.00 0.00
0.01 4.00
0.75 5.00
The first two values indicate a 'remaining capacity' of the pile after buckling of 20.66 kips. The capacity of the pile in compression is 46.89 kips. Since we don't have information for the behavior in tension, we just input some nominal values for the positive deformation branch.
If I input this non-linear relationship for the multilinear link manually, the program accepts it and runs without problems.
However, if I input it through the OAPI, it creates the multilinear link property and assigns it successfully, but it just gives the default Load-Displacement relationship.
I know the code is working because if I use a Load-Displacement relationship like the ones in the verification examples, say:
D (in) P (kip)
-16 -55
-6 -50
-1 -40
0 0
2 50
6 70
16 80
...my code is able to correctly input the Load-Displacement relationship. Note that there are no negative slopes here.
Now, I am sorry for the long-winded description of my problem, but it would be most helpful to hear your impressions on this, ideas on why the OAPI would have problems inputting the same values that I am able to input manually, or alternatives to my general approach.
***As an aside, does anyone know what type of code goes into the "order rows" button in the multilinear plastic link nonlinear relationship section, and how to implement it through the OAPI? I feel this might be helpful as well.
Again, I am most thankful and look forward to hearing from you.
Kind regards,
Oswaldo Russian