Construction staging with compression-only point support spring

Question:

Dear Technical Support,


Subject:  This version is not licensed for Static Geometric Nonlinear Analysis.


I have 10 construction stages (limited by the license I am using: MSENCIV0001005) in the data file, together with compression -only support spring. When I choose the analysis type of material nonlinear analysis, the program would not allow me to run the analysis because the program is not licensed for Static Geometric Nonlinear Analysis.


This does not sound good, I do not ask to include geometrical nonlinearity. The compression-only spring support is considered a material nonlinear problem.


I know that I have three different types of license to choose and one of them has no restriction.


I attached the screen shot and the data file. Could you tell me what is the problem?


Thank you very much.


regards,




Answer:

Hello,

If its just about the non-lienarity of the boundary, then I don't believe its necessary to even use the non-linear analysis option.  The model that was sent was simply analyzed linearly.  The boundary non-linearity is considered inherently and it isn't a geometric or material non-linear issue.  It could be noted from the image below that compression only supports are not active at locations where there is an uplift.
Kindly let me know if further assistance would be required.

Regards,
Nandeep
Technical Manager, MIDAS


Dear Nandeep Gohil,


Thank for your answer. If this is the case, it's good.


For now, it's difficult for me to understand for the mechanical principle behind the linear solution, which should not be able to solve this problem. Before finding the final solution, the program does not know which part of the compression-only spring will be activated or taking no supporting forces; only a non-linear solution could solve the problem.


I'll look at the linear solution results and try to understand the principle behind the solution method. There are compression-only supports: the self-weight will first compress the springs and release the compression gradually when the cantilever segments are added progressively.


Regards,



  


Hello,

That is correct.  Though this is said to be linear analysis, such simple boundary non-linearity is considered automatically.  Also, in construction stage analysis, we basically give the load sequence, so this could done.  The behavior would be exactly as its expected.  Kindly let me know if you have any further doubts on this.

Regards,
Nandeep
Technical Manager, MIDAS
Creation date: 10/17/2018 10:57 PM (dklee@midasit.com)      Updated: 10/18/2018 8:28 AM (dklee@midasit.com)
Files   
Construction Staging with Compression-Only Spring Support.jpg
DataImage89.png
Staging Construction - 10 stages.mcb