Timestep in AMS

Altair Forum User

Hi 

 

I have a very strange situation(in my opinion). I want to run a job with /DT/AMS with a reference  time step 8 times to the conventional case. However my model is not able to run more than 2 times the reference time step. Assuming my reference time step as 0.5 micro second. I am trying to run AMS with a target time step of 4 microsecond which is like 8 times the nodal time step. However my model is running at max of 1 micro sec irrespective of the target time step. Pl suggest me a possible work around so that my simulation runs at the specified time step.. 

gopal_rathore

HI,

Is the error coming as AMS divergence?

Also let us know whether you have applied AMS for complete model or some selected parts.

 

 

Altair Forum User

Hi Raghav,

AMS option is not compatible with all RADIOSS options. In these cases, the target time step will not be honored.

Please go through Current Capabilities and Limitations of AMS in Help Menu.

Altair Forum User

Hi,

 

Yes I have applied AMS to all the parts in my model. I have gone through the current capabilities and in my model I have nothing that is exempted from AMS implementation. Also I have no incompatible kinematic conditions or intial penetrations in the model. The maximum time step that I could apply on my model is 1 micro second. If I try to run the simualtion with higher time steps the simulation job is running with 1 micro seocnd only. There is no drop of time step... Right from cycle 1 the DT is 1 micro second... Could you reason what would be the cause?

Altair Forum User

Hi Raghav,

Please share the out files (starter out and engine out files) of the run.