Learning Forum

[Rommel Jr. Landicho]

Hi everyone! I am currently facing a problem with my model, I think it is on the steel reinforcement. Specifically, why it takes long before it reaches its yield strength.

 

I used steel yielding as a main criteria for RC beam failure. My reference study shows that the beam should have failed at a deflection of 35 mm. However, my steel does not yield until 50 mm which overestimates the maximum deflection the beam could handle. I am sure about the input parameters of the beam because it is just an elastic-perfectly plastic model and the elastic modulus is given from my reference study. I am just wondering why does it take so long for my steel rebars to reach its yield strength when it should be earlier? Does it have something to do with the Menetrey Willam model for concrete? And also, is it right for me to just compare the maximum von mises stress with the yield stress of steel to know if failure governs or is there an appropriate way to deal with this? 

 

I would appreciate any insights. Thank you!

[John Doyle]

Assuming your metal plasticity has been defined correctly, and nonlinear material effects are included.  I would start by selecting the elements associated with the rebar and making sure the material attribute number is associated with the material attribute number that has the metal plasticity defined.  Maybe the assignments are not right.  Beyond that, it is hard to say for sure without seeing more details.