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Say we had a material that was rigid perfectly plastic, with a stress-strain characteristic as shown:

enter image description here

Say that we are drawing this material through two dies, something like this: enter image description here

What would happen if the drawing stress applied were greater than the yield stress?

Of course this is an idealisation, and with a real material, if the stress was raised enough, the material would become plastic and then eventually fail.

However, what would happen with a perfectly plastic material?

VJ123
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1 Answers1

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I am trying to see what you try to say.

If the rate of drawing (say by creating a vacuum) is not such that it will rip the material or create bubbles or fissures it would create something like the figure below! The narrow black lines are a conceptual pattern of what will happen. My apologies for the poor sketching.

The necking doesn't have to be cylindrical. I tried to incorporate a bit of non-symmetry due to possible vortexes in the movement of the paste.

'

plastic movement.

kamran
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