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  1. andreamordini

    modeling a damper with COMBIN37

    Hi all, I model a damper for a time history analysis with the law F=C v^0.015 with the COMBIN37 element. Therefore, I insert in the real constants C1=C and C2=-0.985. the analysis doesn't converge. If I use C2>=0 the analysis works. Any idea or previous experience on the topic? andrea...
  2. andreamordini

    Prestressed modal analysis.

    It can simply be that, due to the problem properties, the external forces you apply have no influence on the modal behavior of the structure. Try to model a tensioned cable: in this case the modal behavior is highly influenced by the axial force. andrea...
  3. andreamordini

    Scaling the ETABLEs

    Hallo Drej, thanks for your reply. Yes, in your way I can manage the output as I want, but I would like to visualize it on the structure using PLLS... andrea ------------------------------------------- Dr. Andrea Mordini Civil Engineer Ph.D. in Structural Mechanics...
  4. andreamordini

    Scaling the ETABLEs

    Hi everybody, I would like to scale the results saved in the ETABLEs by using a factor in order to obtain the results in different units. I tried to use the command SMULT as follows SMULT, var, var, , factor The problem is that the scaled values of var are saved for all the SET in the analysis...
  5. andreamordini

    Imposing acceleration time histories

    Many thanks cbrn! I use the version 10 and this feature is undocumented. Nevertheless, it works. I tried to perform a comparison with OpenSees and I got the same results. Since in OpenSees is documented that double integrastion is performed, I would conclude that this method is used in ANSYS as...
  6. andreamordini

    Imposing acceleration time histories

    As long as I know, it is not possible to an acceleration time histories to a nodes in a transient analysis in ANSYS. Tipycal example a multi support analysis af a bridge where each pier has a different excitation. The same procedure is possible in ABAQUS. My questions: 1- How the procedure is...
  7. andreamordini

    pushover analysis in ANSYS

    As far as I know, it is not possible to perform a real pushover analysis in ANSYS. In fact, in the pushover analysis, the unknown are the load multiplier and the floor lateral displacements except the top displacement. It seems to me that this is a mixed load control-displacement control...
  8. andreamordini

    modifying the model between two analyses

    Actually it is a bit more complicated because in this way the analysis is restarted from the rbd file which is saved at the beginning of the first solve step: this means that the modification of the model is not taken into account. In any case, I solve the problem as reported below. Thanks...
  9. andreamordini

    modifying the model between two analyses

    I need to modify one element between two static steps. Since EMODIF can be used only with a PREP7 I have to solve the first step, enter prep and modify the element, reenter again SOLU. In this way the results of the first solu are cancelled. 1- How can I impose the time running from 0 to 1 for...
  10. andreamordini

    ansys and femap

    Hi all, totally disappointed from the ansys GUI, I was thinking to have a look to femap to be used as a pre and post for ansys. Anyone has some experience? What is possible to control directly by femap and what has to be controlled by ansys? Impressions? andrea...
  11. andreamordini

    femap and ansys

    Hi all, totally disappointed from the ansys GUI, I was thinking to have a look to femap to be used as a pre and post for ansys. Anyone has some experience? What is possible to control directly by femap and what has to be controlled by ansys? Impressions? andrea...
  12. andreamordini

    merging result files

    hi all, I have two subsequent analysis (static, end at time T1 and dynamic, end at time T2) on the same model. Is it possible to merge the relative result file to obtain and visualize a single output? Thanks, andrea ------------------------------------------- Andrea Mordini, Civil Engineer...
  13. andreamordini

    moving mass

    Finally I solved my problem. I define the masses I need and I put some constraints on them. Then, when the masses enter the bridge, I release the constraint and I create a CP between the first mass and the first node on the bridge. In the subsequent step, I delete the CP and I create a new one...
  14. andreamordini

    moving mass

    Hallo doatis thanks for your response. This could be a good idea, but what about if I have more than one moving mass and if the mass values are different? For example one train passing on a bridge with the first wagon heavier than the second... I tried to define all the masses and to connect...
  15. andreamordini

    moving mass

    Hi all, what is in your opoinion the best way to model a mass moving on a line meshed with beam elements? thanks in advance, andrea ------------------------------------------- Andrea Mordini, Civil Engineer, Ph.D. http://www.andreamordini.com...
  16. andreamordini

    /opt module

    I have uploaded one pdf to my website. You will find it in the page Publications, under Conferences: "VCUPDATE, a numerical tool for Finite Element Model Updating", IOMAC. In particular, check the last example of the beam using the Plane model. Always open to discuss. andrea...
  17. andreamordini

    /opt module

    Thanks for your feedback but I disagree. I have written a Newton-based FE updating code and I have performed analysis with 500 parameters with very good results (in publication to international journals). The computational time is acceptable. In order to improve it, however, I was thinking to...
  18. andreamordini

    /opt module

    I started using this module but I found out that the maximum number of parameters (design variables) is 60. It is a very small number to perform Finite Element Model Updating. Can anyone explain why ? (from the theoretical point of view) Is it possible to use more parameters using some numerical...
  19. andreamordini

    defining a beam section

    Orientation nodes seem to be one possibility. Any other idea? Andrea ------------------------------------------- Andrea Mordini, Civil Engineer, Ph.D. http://www.andreamordini.com -------------------------------------------
  20. andreamordini

    defining a beam section

    Could you explain please how? thanks andrea ------------------------------------------- Andrea Mordini, Civil Engineer, Ph.D. http://www.andreamordini.com -------------------------------------------
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