When I run material non-linear analysis, why beam stress appears to be higher the specified yield strength?

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Answer:

Hello,

I noticed that when I only look at the axial stress it only reaches the yield strength but for bending it does not. Does the plastic material in Midas civil only account for axial loads?

The material nonlinear analysis for the beam element is performed based on the stress resultant beam model theory as shown in the online help.


Thus, the nonlinear behavior of beam element starts to occur after the plastic axial force or plastic bending moment is reached instead of yield stress,.
- Plastic axial force = Area x yield stress
- Plastic bending moment = plastic section modulus x yield stress

If you want to consider the plasticity in which some part of the section is plastic and the remaining part is elastic, it is recommended to use plate elements rather than beam elements.

Regards,
DK Lee