Learning Forum

[Tony6]

I am running an explicit dynamic analysis for a car crash and i am using Al 7075 T6. From literature, i was able to obtain the johnson cook parameters for this material.

The same material in the explicit library uses the steinberg guinan model and produces a perfect stress/strain plot.

Why cant i produce a similar plot using the johnson cook strength model?

[Ram Gopisetti]

we see no problem in generatign the curvs on our side given that SG strengh is supressed in same material model.
waht version of ANSYS adn licence do you hold ?
Cheers, Ram

[Tony6]

i am using R18.2 and dont really have the freedom to upgrade it. Is there anything i can do to fix this from my end?
I noticed you used an explicit material and added johnson cook model, i used general nonlinear material and added the johnson model after. Could that be the reason?
I could not use an explicit material directly since i am using surface geometry and shell elements

[Tony6]

Hello, i hope you received my comment and can reply. I would greatly appreciate it as this is very important for my thesis thanks.

[Ram Gopisetti]

i guess its not true, i could able to get the cuves by having an BISO model as in following image.
and what do you mean by " I could not use an explicit material directly since i am using surface geometry and shell elements" , there is no elemental limitation for this material model and what licence do you hold ?
Cheers, Ram

[Tony6]

When i apply BISO model, it automatically suppresses johnson cook strength and vice versa. They cant work together as they are both different plasticity models. I still cant generate this graph that you have and i dont know how to fix it