Lumped Plasticity hinge stiffness

[aladdin76]

Hi all

For lumped plasticity model of a column or a beam the plastic hinge stiffness is 6EI/L (assuming double curvature).
My question is how to derive this equation? and what is the stiffness for a singe curvature (cantilever)?

Thanks

 

[JasonMcKee71]

for single curvatue, it is 12EI/L

Jason McKee
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