| Applies To | |||
| Product(s): | AutoPIPE, | ||
| Version(s): | All | ||
| Area: | loads | ||
| Original Author: | Bentley Technical Support Group |
Comments, Questions, and Answers:
Item #1:
Partially Filled Liquid Pipelines or Hot Sun Exposed Pipes, see Example Model here.
The Load/Thermal Bowing command enables the user to calculate thermal bowing separately or included with all or one thermal load case which can cause severe stresses on the piping. Thermal bowing typically occurs when transporting fluid on a partially filled pipe but can also occur in exposed pipes in hot climates where one side of the pipe is exposed to the sun and the other side is in the shade. In this case, the top and bottom of the pipe section can experience a significant temperature differential. This temperature differential causes pipe thermal strains which produce pipe curvature.
To simplify the problem, AutoPIPE assumes a linear thermal strain distribution across the pipe. With this assumption residual stresses vanish and only pipe curvature stresses exists.
The assumptions in AutoPIPE are:
1. Linear thermal strain distribution
2. Apply only to horizontal or near horizontal pipes with bowing in the local vertical plane
3. Same thermal gradient or temperature change is applied to all pipes. Or, cannot specify different thermal bowing temperatures for different pipes.
See AutoPIPE help for complete details on this feature.
Item #2:
How can i apply thermal bowing on only Static Analysis set #3?
When i check the thermal bowing option for analysis set 3 it is also checked for the other analysis set. this occurs in spite of the fact that i specified : apply thermal bowing to thermal case T2 only in thermal bowing definition window.
Answer:
At this time, Thermal bowing is applied to all Static Analysis Sets. It gets associated to one or all thermal load case based on the "Add thermal bowing to all thermal cases" setting. If unchecked, the user will have the option to specify a single load case for which thermal bowing effects will be added (if thermal bowing option is checked in the static analysis).
This may be confusing to some users, when Thermal Bowing option is enabled inside of any Static Analysis set, there is no warning or indication that it will be applied to ALL analysis sets. The original intent was to turn it on an off during all analysis sets and not individual set.
The CAE development team is considering one or more of the following options:
A. Consider making Thermal Bowing an analysis set specific option (TFS-E567636)
B. Add a warning that this applies to all analysis sets.
Workaround:
Only use thermal bowing with its own thermal case
See Also
Loads and Load Sets - AutoPIPE