Moment-curvature
I am trying to do a simple column moment-curvature analysis. It's a 4.5' dia. RC column. Longitudinal bars are 40 - #6 bars. Spirals are #5 @ 3" pitch with 2" clear space to the surface. Axial load is 1000kips compression. I have the following questions below.
1. The help manual doesn’t provide guidance on the appropriate inelastic material models to use for moment-curvature analysis. I have defined the inelastic material properties using the Mander model for concrete and the Park model for steel. When I try to choose the concrete model in the moment-curvature window, the Mander model previously defined is not available. See image below and attached model. Please advise on proper input definitions for moment curvature analysis in Midas. Is there an example? YouTube video examples?
2. The first time I ran the model, I used the Kent & Park model for concrete, but the moment-curvature curve that it produced was incorrect. As defined using the Mander model, it won’t perform a moment curvature analysis. If Midas doesn't allow use of the Mander model, how do we input confined/unconfined concrete regions within the section (i.e. concrete within the spiral and concrete outside of the spiral)?
3. As for the rebar inputs used to define column reinforcement, what do the Size 1 & Size 2 inputs correspond to? I only have one size of rebar for my longitudinal reinforcement. Also, what does the "Ties/Spirals Number" input define? Moment curvature is a sectional analysis, I am unclear what this input defines. Is it the number of spirals in the cross-section (i.e. interlocking spirals)? Please advise.
4. What is shown in the Section Shape window? It appears that only longitudinal reinforcement & section perimeter are shown. Does Midas show confined & unconfined concrete limits within the section? Spiral reinforcement? Please advise, it is not clear from the input window what is being shown.
Thank you for your help in this matter. I really appreciate your time and consideration on these issues/ questions.
Answer:
Hello,
Thank you for your patience. Kindly refer the response to each issue below.
Regards,
Nandeep
Technical Manager, MIDAS
Hello,
We have a response from the developers.
Hope this helps. Kindly let us know if further assistance would be required.
Regards,
Nandeep
Technical Manager, MIDAS
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Column_Moment_Curvature.mcb 41 KB |
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