Problem:

Can AutoPIPE V8i Import / Export Bentley HAMMER loads?

Solution:

We apologize for the inconvenience, however at this time (June 2015), AutoPIPE V8i cannot directly import/export loads with Bentley HAMMER. This has been logged under the following enhancement,

CAE-CR-4560: Add the ability to import time history load file from Bentley HAMMER. 

Workaround #1 - import loads:

Using the Fluid Transient command to create a flow path as modeled in Hammer. This will automatically create the required THL and the TIH files needed. Open the folder where the model is stored to see all these files. 

Now, update the files as required based on the data from Bentley Hammer:

The way to get pressures or forces from Hammer at this time is through "Transient Results Viewer". In this viewer you have a graph tab and a data tab. Copy the data from the Data tab by selecting it and copying and pasting to notepad or Excel.

Note: directional data in Bentley Hammer's grid is not usable in AutoPIPE

For each bend in the model Create / update an AutoPIPE TIH file (see AutoPIPE help for special formatting of an AutoPIPE TIH file). The name would be limited to 8 characters and would include the node name or number and has extension TIH. The data in the file would be in forces units (actually always in lbs regardless of units used). The data written would simply be the nodal pressure times the inside area of the pipe or F = P*A . 

Note: the force pressure generated in Bentley Hammer is more than just pressure * area. The forces computed by HAMMER include a term for the weight of the fluid, and take into account the momentum of the fluid (so if the fluid flows around a bend the force will be higher than a straight pipe run, etc.).  However, AutoPIPE needs the net axial unbalance force between two bends(or bend and valve or end cap). A new enhancement can be added to include friction and momentum as other programs do.  Assuming friction and momentum are ignored, which appears to be conservative, just output nodal pressures on each bend instead of differential pressure. This way the user can account for axial forces between bends.

The TIH file has header information as well has two columns one for time in seconds and another for Force in lbs.

Example TIH file format:

File name:         TIME1.TIH
First line:            file name
Second line:     number of points using Fortran I5 format (right justified starting on fifth column), and file type of 5 (to mean force) also using I5 format.
Lines 3 to end contain two columns.
First column from 1 to 10 have the time in seconds
Second column for 11 to 20 have the force in lbs(regardless of units)
Please note that you need to write data in E format if value exceeds 10 decimals(i.e. does not fit within 11-20).

Save this file to the same folder where the model is stored. Adjust the THL file as needed. Again, using the AutoPIPE help as a guide for the formatting a THL file.

Note: Force, length and velocity in a THL file are for information only and not used by AutoPIPE analysis.

Workaround #2 - import model geometry:

AutoPIPE does not import i-model files directly. Should be able to export Bentley Hammer to ProStructures or OpenPlant and then exported to PXF for Piping into AutopIPE and possibly use export to Structlink to STAAD to bring structure into AutoPIPE using PIPELINK.

Note:

1. if an enhancement has not already been added to the program, log an enhancement request with the respective CAE number. The more requests per an enhancement, the quicker the CAE development team will add that feature to the program.

2. See training video on this subject here: AutoPIPE's Built-In Fluid Transient Analysis Can Easily Define and Solve Difficult Fluid Shock Loadings

See Also

Import and Export

Bentley AutoPIPE