save only a part of time integration

Luca Cavagna

I am running motionsolve with a template with 2 or 3 <Simulate> commands. The solver uses sensors to decide when to stop one time-integration. These are dummy time-histo. Only the last time integration is of interest. Is there any way to allow plt and all the output files to chop the time histo and save only the last integration?

GTT Adam

Hi Luca,

One method to limit the amount of output data is to set the Print Interval to a large value, and then use a Sensor to change the Print Interval by checking the "New Output Step" option to be the desired step size. This way, the solver will only produce 1 or 2 output steps to the H3D or PLT before the Sensor is triggered. In your case, you could set the Print Interval to be 1 second until the Sensor is triggered, and then update the Print Interval to be 0.001. 

 

If you only want to limit the output to the H3D, you can do so by navigating to 'Global Simulation Settings >> Output Settings >> H3D >> Write H3D Results Starting At'. This will not limit the PLT outputs however.

 

Finally, you can use a Template to set the outputs off, run for a few seconds, then turn the outputs back on like so:

<ResOutput
    mrf_file            = "TRUE"
    abf_file            = "FALSE"
    plt_file            = "FALSE"
    plt_angle           = "YAW_PITCH_ROLL"
    flex_vel_acc_output = "TRUE"
    contact_gra_output  = "TRUE"
/>

<Simulate
analysis_type       = "Transient"
end_time            = "5.0"
print_interval      = "0.01"
/>

<ResOutput
    mrf_file            = "TRUE"
    abf_file            = "TRUE"
    plt_file            = "TRUE"
    plt_angle           = "YAW_PITCH_ROLL"
    flex_vel_acc_output = "TRUE"
    contact_gra_output  = "TRUE"
/>

<Simulate
analysis_type       = "Transient"
end_time            = "5.0"
print_interval      = "0.01"
/>

 When you review the PLT file. it will start at 5 seconds. You can combine this with a Sensor such that the first simulate/transient runs for well beyond the runtime, the Sensor then HALTS to move onto the second simulate/transient, which lines up with near the end of your simulation. 

 

Hope this helps!

Adam Reid