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[arunprabhat12]

Sir/ Maam

I have to calculate the maximum axial load that a column can carry. For that, I need to increase the axial load gradually say for the rate of 10 KN/ m-sec and note down the axial load value at failure. Strain failure criteria of 0.2 is given.

There are 2 columns one steel I section and other is RCC column.

I am working in ANSYS Workbench.

How can I get the failure load value?

 

[jj77]

You could plot the load displacement curve:

 

See here for more details:

 

/forum/forums/topic/plot-force-displacement/

 

 

[arunprabhat12]

Hello

I have to calculate the axial load carrying capacity of a steel column after getting damaged by blast loading.This has to be done in these steps

I am working in ANSYS WB 15. Should I perform analysis in explicit dynamics only or other than the blast loading steps in the transient analysis?

[peteroznewman]

How exactly is the blast load applied to the column?  Is it applied to faces on only one side of the column?   Is it a pressure-time load history?   Is the pressure uniform or does it have a shape along the column?

How are you modeling the column?  Solids?

Since the graph is showing 600 ms, it looks like Explicit Dynamics would be a good fit. Do you have an Explicit material for the column that can be eroded by the stress of the blast?

[arunprabhat12]

I am applying blast on one flange of column uniformly over the whole length as a triangular pressure time history.

As I am learning phase of ANSYS I am also confused about what element type I should take for the best results.

The material here is elastic plastic steel. So I am taking  Structural Steel NL. As failure criterion of 0.2 is given, so I added plastic strain failure EPS criteria (is it right?)

[peteroznewman]

If you build the model in Explicit Dynamics, in Solution Controls, there is a setting for Erosion where you can set a Total Strain value of 0.2 (the default is 1.5). When an element reaches that value of strain, the element will be removed from the model automatically.  Just let the software select an element for you.

[arunprabhat12]

Thank you for your help

I have done this analysis in Explicit Dynamics and got the following curve between axial load and deflection. The analysis got stopped by the time around 461 msec (maybe because of the erosion of elements). 

From this graph what value should be taken for the collapse load.

The workbench file is attached here. Please check the modeling part also because when I changed mesh type to hex-dominant results are quite different.

https://drive.google.com/open?id=1egXyZfDotTAeyfU6gYukVCsoW78qWfJ3