nDMaterial Drucker Prager

[kgkoktsi]

Hi everybody!

In the command manual of Opensees-http://opensees.berkeley.edu/wiki/index ... er_Prager- the example of a brick element with the nDMaterial Drucker Prager gives the following note:
"the element is loaded until failure, at which point the model can no longer converge, as this is a stress-controlled analysis".

The model I use consists of 5000 stdBrick elements with the nDMaterial Drucker Prager subjected to a uniform excitation pattern with the duration of 40sec. But, the analysis can no longer converge at 1.16sec. Does this mean that the analysis fails to converge the moment the first failure of an element happens? And how can I solve that problem? In reality, the fact that one element fails doesn't lead to a structural collapse....

Thanks a lot!

[vesna]

I never used that material but I guess that in case of the element failure you should get a message about what caused the failure or convergence problem.

In case you do not get any warning message record the state of your elements to see if any of them filed during the analysis or if it is just a convergence problem that can possible be overcome.

[saumyashah]

hey kgkoktsi

so finally is your problem solved,i am also trying to work on similar type of model, if possible can you please post the script of your program it will be very helpful since i am new to open sees