Hello

When I give the wind shape factor in the piping system, Caesar, in the load case options, creates 4 wind load cases for the lateral directions changing the direction cosines. My question is, whether all the four wind load cases must be considered in my analysis (build up of cases) or can I just consider the wind load in one direction (either positive or negative)for each lateral axis,and check the stresses and use absolute value of the wind load to find out the maximum load at any particular support?

Normally the wind direction and speed is mensioned in the site data.
This data is collected after studying the records throughout the year.
I consider wind at least in two directions perpandicular to each other.
If site data shows wind towards North (-X coord.) for e.g. I consider Win1 -X and
Win2 -Z.
And during the addition of loads always add wind loads seperatly to maximum OPE
loads with same sign as that of OPE loads. This is to check unpredictable wind directions.
There are some more factors to be considered,
- Piping elevation from ground.
- Surrounding of Piping. If Pipes are in building wind loads can be ingnored.
- Wind velocity profile. You can input the Elevation Vs Wind velocity in caesar load cases.

Hope our friends adds more on this topic.

Note that with Version 4.40, you can look at <em>positive</em> and <em>negative</em> directions simply by building additional load cases. For example, assume:

• WIN1 is +X
• WIN2 is +Z

then

• 1) W+P1+T1+WIN1 (OPE) is operating plus wind in +X
• 2) W+P1+T1-WIN1 (OPE) is operating plus wind in -X
• 3) W+P1+T1+WIN2 (OPE) is operating plus wind in +Z
• 4) W+P1+T1-WIN2 (OPE) is operating plus wind in -Z

So, checking <em>positive</em> and <em>negative</em> wind load directions is simply a matter of defining additional load cases.

It is also worth pointing out that CAESAR II has the ability to help find the worst-case loads/displacements/stresses contained in many other load cases, and report these MAXIMUM results in one additional load case.
This is done in the Load Case Editor.
Simply set up an additional load case containing the other load cases you want to filter through, set the load type, and then on the Load Case Options tab, set the 'Combination Method' to 'MAX' for this new load case.
Using Rich's example load cases, this would work as follows:

1) W+P1+T1+WIN1 (OPE) is operating plus wind in +X
2) W+P1+T1-WIN1 (OPE) is operating plus wind in -X
3) W+P1+T1+WIN2 (OPE) is operating plus wind in +Z
4) W+P1+T1-WIN2 (OPE) is operating plus wind in -Z
5) L1+L2+L3+L4 (OPE) & set Combination Method to MAX.
This will compile all of the maximum results for cases 1 through 4 and summarize them in a single load case.