The following Error message appears when running the program:
No. 593 Saddle effective angle < 30Deg (blast int Max P (Corroded inertias) (Corroded Weight), revise design of vessel.
How to avoid?
Let's understand why we get the following 2 errors:
Suggest to watch webinar:
"Consider motion, seismic, and wind loadings with ease for optimized pressure vessel supports design"
The webinar will help in understanding an exactly similar case considered with motion loading.
Example:
Let's consider what happens to the saddle 2 design. In this case the horizontal transverse reaction is 0:
Hence the effective angle is same as actual saddle angle (107.84 deg >30 deg) and the saddle design passes:
When you applied very high wind dynamic pressure for a load case (i.e blast analysis), it lead to high horizontal transverse reaction (ex. 18,428.2 daN)
Hence now the effective angle theta
theta= 107.84 - 2.arctan(Rah/Rav)
theta= 107.84-2.arctan(18,428.2/1,714.1)
theta= 107.84-2.arctan(10.7509) < 0
Note: less than 0 makes no sense, so theta = 0.
Therefore, the error and the saddle design needs modification. Generally increasing number of saddles and parameter B in saddle dialog box may solve the problem. However, if the load case (ex. blast, wind), drag dynamic pressure is very high then this suggestion may not work. Another suggestion increase the number of saddles or adjusting B. You may try it and also see if the blast drag is realistic. A simplistic static blast load wind dynamic pressure calculation may be over conservative and may lead to impracticality in design.
Please verify the blast drag from reliable source. Users considering blast load usually have access to known blast drag dynamic pressures which we do not have access to.