Problem with PostView generating different graph scales

[pcundergrad]

Hi all,

I am carrying out an analysis which involves producing a chart/graph showing effective fluid pressure for selected elements each time I run a new simulation.

For my first simulation, when I created a chart and saved it to then import into Excel, there was 74 time steps and I found that PostView had saved the data in logarithmic form. However, the next time I ran a new simulation and created a new chart (after making some modifications to my model), there was now 1006 time steps because PostView saved the data in linear form. I can't work out why it suddenly changed the format of the data. Can anyone help? Apologies if this has already been addressed but I couldn't find a thread discussing the same issue.

Further info that might help:

- I did not alter any of the Step Properties in Preview, I only made modifications to my model.

[maas]

Hi,

PostView just stores the data as is, so the cause of this behavioral change most likely lies with FEBio. I suspect that the first model ran better than the second and the auto-time stepper took larger time steps. There are some parameters that you can play with to control the time step size. The most obvious way to limit the time step size is to set the dtmax parameter to the desired value. However, this may still not produce the exact same time steps between models. If that is what you want, you can either turn off the auto-time stepper or use a must-point load curve. Please consult section 3.5.1, comment 4 of the FEBio User Manual for more information on the auto-time stepper and let us know if you have any further questions.

Cheers,

Steve

[pcundergrad]

Hi,

thanks for replying. To get around this problem I followed your advice and simply matched the number of time steps and turned auto time stepper off in both models to achieve similar results.