Doubt about implement a pressure (time and space varying) starting from Dytran results

To apply a time-varying pressure field extracted from a previous simulation step to a deformable structure in Dytran/Nastran, you need to map the pressure data onto the structure's surface as a spatial and temporal field. This involves using the pressure data from the .arc file and defining it in a way that Dytran can apply it as a dynamic load over time.

In short process should be like this:

1. Extract Pressure Data: You have already extracted the pressure data over time from the coupling surface in the first step of your simulation. This data is typically stored in an archive file (.arc).

2. Prepare the Pressure Data: Ensure that the pressure data is formatted correctly for use in Dytran. This involves organizing the data so that it can be applied as a load over the structure's surface. The data should include spatial coordinates and corresponding pressure values at each time step. You might have to write some scripts to automate the things here if data is large. 

3. Define a Spatial Field: In Dytran, you can define a spatial field that maps the pressure data onto the structure. This involves specifying the nodes or elements on the structure where the pressure will be applied. You can use the TABLED1 entry to define a time-dependent table of pressure values that correspond to the extracted data.

4. Apply the Pressure as a Load: Use the TLOAD1 or TLOAD2 entries in Dytran to apply the time-varying pressure as a transient dynamic load. These entries allow you to specify the time history of the load, which can be linked to the TABLED1 entry that contains your pressure data.