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robbievanleeuwen / concrete-properties

Calculate section properties for reinforced concrete sections.
https://concrete-properties.rtfd.io
MIT License
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Strand stress-strain profiles have compression branch. #82

Open Agent6-6-6 opened 1 year ago

Agent6-6-6 commented 1 year ago

Hi @robbievanleeuwen

Design codes often have rules around strand not being effective as compression reinforcement. So expectation would be that there would probably only be a tension branch for the strand materials not tension and compression.

If you're aware of some codes allowing strands to be utilised in compression, then a boolean variable could be added to only return the tension branch (or a boolean variable to return both branches, with a default of just the tension branch being created).

From NZS3101 for example:- image

robbievanleeuwen commented 1 year ago

Thanks @Agent6-6-6, will implement this. Just curious if this is for unbonded strands only or also bonded strands?

Agent6-6-6 commented 1 year ago

Generally only use bonded in NZ (similar to Australia as I understand it). Don't think the NZ code really differentiates between bonded or unbounded for that particular criteria.

I think the fundamental issue is Strand just buckles or compresses longitudinally like a spring with the individual wires just unable to take any compression, doesn't have the same resistamce to buckling as a solid reinforcement bar I guess.