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  1. arigato

    SAP2000 - nonlinear static analysis

    Hmm maybe I am missing something, but unless you have hinges or nonlinear links in your model, your going to get elastic behavior out of your structure, and should result in a linear pushover curve. Is this what you wanted? The unbalance check comes from the solution trying to converge to a...
  2. arigato

    Convergece error

    Bah typos....
  3. arigato

    Convergece error

    Hi folks, Im working with SAP 9.0.3 at the moment and I am running a nonlinear time history for a simple shear 3-story building with hinges located at the ends of the columns. My hinges account for nonlinear effects in the model. My floors are assumed to be rigid diaphragms. I have no...
  4. arigato

    Good Reference Book for SAP 2000

    Not sure if it will meet your needs, but you could check out the latest version of Structural Dynamics by Paz and Leigh which incorporates SAP 2000 problems in addition to regular non computer based problems. It explains the steps you need to do in order to create the problem in SAP and then...
  5. arigato

    diaphragm modelling in SAP2000

    This topic helped me on an analysis that I was working on thanks! One way to determine if the rigid vs flexible diaphragm is the right assumption is to run one case with both types of constraints and see how much of a difference there is in the reponse of the 2 (shears displacements etc). If...
  6. arigato

    Bolts, Nails, Material Properties

    The values for bolts and nails depend on the strength desired from them. You can look up commonon material properties in the back of a mechanics of materials book. Bolts come in different strengths like low strength type used in bridges: ASTM A307 or high strength such as ASTM 315 and ASTM...
  7. arigato

    Time History Problem

    Hello all, Im running a direct integration non-linear time history for a one story, steel frame building with sap vs 9.0.3 and noticed that I had the same displacement results when i used a plastic hinge with a value of say 100 ft-kips and one with 50 ft-kips. Now this error can be to many...
  8. arigato

    Doing multiple analysis

    I tried your idea but it didnt work. I can't open a SDB file to modify it with a text editor, and the batch file control will only run files that are actual sdb files. Exporting to a .s2k file and changing the extension to sdb doesnt work either. What I did was take the input .$2k file and...
  9. arigato

    Wood section library

    For materials properties Id check out a book on mechanics of materials, they tend to have a decent list of wood types and material properties in the back of the book. You can define your own hinge with the stress strain curve that you are looking for. Since you are defining a hinge you really...
  10. arigato

    Doing multiple analysis

    Hey all, I have to create alot of small models which deal with seismic behavior. Im using plastic hinges to take care of the nonlinear material properties in my models. Is there any way to avoid having to create a seperate model or physically assign a different hinge value to my members...
  11. arigato

    Wood section library

    You can always go to define>materials>other and select modify show material and enter the properties for your wood there. If your working with plastic hinges youll have to define properties from define>hinge screen.
  12. arigato

    Modeling Cables in SAP

    What stiffness is being lost at the joints? axial rotational? Did you apply nodal loads in between the truss members along the cable to represent the self weight of the cable or the applied loads? Another idea might be to insert a ton of hinges with low Mp's into the frame memebrs you are...
  13. arigato

    Modeling Cables in SAP

    Hmm Ive never tried modeling a cable before but I would try a series of 2 force members (truss memebers) pinned at their ends before I would use frame memebers. By definitions cables cant take compressive forces very well and dont resist moment all that great either.
  14. arigato

    Imbalance of Forces

    Hello all, I posted earlier with this problem but I dont think I was clear enough in stating what my problem is. I am using version SAP 8.2.3 and I have a small, square, one storey structure (concrete unreinforced) and ran the following time histories using EL centro (just one lateral...
  15. arigato

    How to define reinforcement in Pushover

    You should be able to specify reinforcement in a frame member when you specify the material of that member as being concrete. I havent played with it much myself but it appears you can specify the steel and where it is located. Check out the online help and manual for more details.
  16. arigato

    Special time-histiry analysis problem!

    Igor, Using hinges is probbaly best way to define non-linear material behavior in a frame element other than defining link elements or a limiting load scenario in the elemnt. To define hysteris curves in frame SAP elements you need to define frame hinges first. If you to define>frame hinge...
  17. arigato

    hinge unloading

    Hmm. Im not convinced that the internal forces are equal to zero but my advisor last week said its not possible to have residual forces if there are no applied loads such as gravity involved. Ill present the damper case to him and and see what he says. Thanks
  18. arigato

    hinge unloading

    Im using version 8.2.3 and the manual i have for it clearly states that I can use hinges for non-linear time history analysis. Do they not work well if your not using version 9.0? I am having a problem with a small and simple one storey 3d structure (with offset mass to create torsion) with...
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