Observation on the external work result

[soildynamics]

-I am running ElastoPlastic analysis. With application of the load, the external work of the whole model(History Output) at a specific step reaches a peack and starts to become a decreasing function of time, although the load is increasing. In the following steps the external work becomes a decreasing function with time.
I do not understand the underlying physical cause for this outcome.
My energy equation
E(external force)= E(elastic)+ E (plastic dissipation)+E(artifical damping)
-Also ..I tried to get the External work on an element/node level . but I do not know why I am getting zero values
thanks for help

 

[gurmeet2003]

Why do you care so much about external work?

Gurmeet

 

[soildynamics]

not really ... but what is observed is interesting
decreasing the external work while the applied load is increasing could means that the applied load on the porous medium is not producing work any more...

can you physically interpret that..?

does that flag failure..?