Learning Forum

[javat33489]

Hello everyone.
I am again conducting an impact analysis of parts and I have a question.
My model is 1/4 of three cylinders (I am currently doing an analysis without symmetry for testing). The two lower cylinders are secured, the third one falls inside. But it does not fall just like that. First, tension up to 6 tons occurs (in this case, the 1\4 model means 1.5 tons) and then the part suddenly breaks off and falls on the surface of the other.

How to simulate tension or how to calculate the initial speed with initial tension?

I found the initial velocity:
- load 1500 kg
- height of fall 30.9 mm
F = 1500 x 9.81 = 14715N
A = Fs = 14715 x 0.0309 m = 456.31Dj
A = mv2/2
v = 0.780 m/s = 780 mm/s

And used it in transient analysis:

But this is not the speed when the falling cylinder was initially stretched to 6 tons.
Tell me how to do this?

[Ashish Khemka]

Hello,

Two suggestions:

1. You can apply the pretension in a static analysis and then import the deformed geometry and apply the initial velocity to the deformed body. 

2. For an impact problem you may try performing an explicit analysis.

Regards,

Ashish Khemka