Exceeded plastic moment capacity for beam hinges

1

Hi,

The plastic moment capacity is defined as 500kNm for piles but it is exceeded considerably without the forming of plastic hinge in dynamic analysis.

The definition of plastic moment capacity:

image
image945×200 90.1 KB

The moment values at X axis and 500kNm limits by red marks:

image
image945×642 134 KB

Time step is 1.083e-4. I thought that it might happen only at the time step passing instant. However, the moment values are getting increased even after the time steps at which the closest bending moments to the plastic moment capacity is passed. You can see it from the following “Time step – Moment” table.

image
image583×536 136 KB

What can be the reason? Is there any way to take at least 519 value (the value coming right after 500)?
519 is OK but 581 is too much. It is 16% greater than the value chosen.

Could you help me please?

Kind Regards,
CGulenc

2

What damping are you using for the structures (links)? We need the datafile to duplicate the issue and then have an investigation. Please send the complete datafile to flac3dsupport@itascacg.com.

3

Thank you. I used 2% Maxwell damping for structural elements.
Then, I have neglected the damping for structural elements. The results are perfect now.
You can see as follows. Does it mean that I cannot use damping for structural elements?
I will send my files.

image
image1144×546 77.6 KB

5

Hi,

Why does Maxwell damping has such an impact on plastic hinge convergence?

Thank you,
CGulenc