LS-DYNA Stress Output 1

[Leibi]

Hi,

are the stresses output by LS-DYNA for example via a fringe plot or a graph by ASCII Element output engineering stresses or true stresses?
The stresses are always described as "effective stress" but I'm not sure wether they are engineeringe stress or true stress

Many thanks in advance!

Best regards,
Leibi

 

[missil3]

The effective stress output is the Von-mises stress. The stresses/strains output in fringe components and ASCII databases will be true stresses/strains unless stated otherwise (I am not sure if there is an option to output engineering stress/strains instead).

In some material models you have to input engineering stress-strain curves instead of true stress-strain curve. For the most part its true stress/strain.

 

[Leibi]

Hi missil3,

I did some calculations.
The strain ouput by ELOUT via ASCII is engineering strain.
I calculated the engineering strain based on the node displacement and the calculated strain fits perfect to the curve plotted by ELOUT.
For the strainrate output LS-DYNA calculates the true strain and derives the strain rate from the true strain, so the plotted strain rate can be used directly since based on the true strain.

The stress output via ELOUT is true stress, I verified that.

Thanks!!!

Regards,
Leibi