.k - Pipes - Modeling in AutoPIPE


Item #1:Comments, Questions, and Answers on modeling approach for Pipe Runs in AutoPIPE:

Need to find out what the maximum suggested length between two points on a pipe run is, as it seems to affect the displacement (visually at least). I.e. i have a point to point run of 5m when i subdivide this run into 4 sections (adding 3 points) the deflection appears to change. What then is the limit of convergence of the results?

Answer:

When running a non-linear analysis, the specified settings for the model to converge can be found under:

(For AutoPIPE V8i 09.06.00.xx and lower) Load> Static Analysis sets> select a non linear analysis set and press the modify button> press the OK button, the following is displayed:

See the online help for details on this dialog. 

About the maximum spacing between node points, the animations shown in AutoPIPE are extreme exaggerations of the results. Recommend to not use the visual representation, but refer to the actual results for actual displacements of node points. The animation is a good tool in understanding what is happening to the entire model. The closer the node points are modeled the more accuracy of the results along that span of pipe. With node point further apart, the application accuracy is still the same but you do not have as much information along the entire span as if there were more node points.

To answer this question directly, the displacement results at corresponding node points would be the same.

Example:

Given the following model:

The Results displacement at corresponding point A02 / B05 are identical

Only difference is that segment b has more results along the span of pipe between B00 - B05 than does A00 - A02. 

See Also

Modeling Approaches

Bentley AutoPIPE