| Applies To | |
| Product(s): | AutoPIPE |
| Version(s): | ALL; |
| Area: | Modeling |
| Date Logged & Current Version |
June 2022 |
Problem:
When performing an analysis with an incline support configured as shown below, will the Spring Rate setting be ignored or considered during
a. Linear analysis?
b. Non-linear analysis?
c. Dynamic analysis?
d. SAM analysis?
Solution:
As indicated previously (here), with an Inclined support modeled as shown above, and If the model was to perform a Linear analysis, Dynamic analysis, or SAM analysis, then Yes only the Spring rate would be taken into consideration during the analysis, meanwhile support gap(s) and all Ultimate Force Gap settings would be ignored.
However, when performing a Non-linear analysis, than the Spring Rate value would be ignored, meanwhile the support gap(s) and Ultimate Force Gap settings would be considered. Under no conditions would the analysis consider both the support's Spring Rate setting and Ultimate force gap settings.
Again, when Ultimate force gap is enabled, only the values entered for for the support's gap(s), Breakaway force, Stiffness K1 & K2, and Phase are considered. Meanwhile, the Spring rate value will be ignored.
Example:
Using AutoPIPE Example model Walkthru.dat, delete the spring support at B01 and anchor at B04. Also change the analysis from Linear to Non linear. Next run the analysis and check displacements at B01.
Note the vertical movement
Select Node point B01 and insert the following incline support
Rerun the analysis and check the displacements again at B01.
Notice that the vertical movement is exactly the same. Why?
Correct, because Ultimate force gap was enabled and Non-linear analysis was performed. Thus the rigid Spring rate was ignored, only the support gaps = 0.00, and the Ultimate force gaps settings were considered.
Note: Please take a moment to review AutoPIPE help:
Help > Contents> Search Tab> enter "Understanding Ultimate Force Gap Supports" (include the quotes), press List Topics button, double click on the selected topic from the list provided to see more information.
See Also
W2261-9: All stiffness values are zero for the following bilinear support(s).