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[jjaafar68]

Dear all, 

 

I'm using Ansys Apdl v16 to model simple concrete beam under static load by using Solid65 element.

after plot load-displacement curve , the curve stopped at the maximum load, unlike experimental there are no negative slope in the curve. 

my question is, 

is there any way to plot full load-displacement curve with the negative slope ? like the graph. 

 

[mekafime]

Hi,

I usually change the sign in excel

[Sandeep Medikonda]

Hi, Isn't that post-buckling behavior?

Did your model run to completion? I suspect it hasn't?

Buckling is a numerical stability and your tangent stiffness matrix is going to zero.

You can overcome buckling by adding some stabilization energy to your model.

Regards,

Sandeep

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[peteroznewman]

What was the load in your model: a force or a displacement?   A force load cannot solve past the maximum force, that is why it is required to have a displacement load on your structure and extract the reaction force. A displacement load can track a reaction force reaching a maximum and then plot the negative slope.

Regards,

Peter

[OguzhanA]

But if we have to apply environmental pressure (like external pressure) to a cylinder, we can't add displacement there, right?n