Hi all,

PROBLEM: ASCE#7 WIND LOAD PARAMETERS - there is a change in displacement once global co-ordinates corporated.

I am doing a piping system connected to Pre-heater.

I have considered wind for this system & used ASCE#7 WIND LOAD PARAMETERS for wind cases,version CAESAR 5.0.

During my preliminary analysis I haven't incorporated the global co-ordinates(Y=000mm).System is safe in wind case.

But in the later stage, once I incorporated the Global co-ordinates(Y=644650mm), system fails in wind condition.

When we use ASCE#7 WIND LOAD PARAMETERS it doesn’t have effect in elevation wise, hence it same for all elevation. So if a pipe is place at 0 elevation or 20m elevation will have the same displacement as per ASCE#7 WIND LOAD PARAMETERS.

Whether the ASCE#7 wind load parameters will varies for elevation wise.

Regards,
BVK.

Yes, wind load varies with elevation. The wind load profile is parabolic in shape.

You MUST define the elevation of the first node in the model correctly if you want correct wind loading.

bvk,

Let me add one more thing.

The elevation you define for your first node needs to be with respect to the ground at the structure location.

You stated your elevation as 'Y=644650mm'. I doubt you're that high above the ground. If your plant uses elevations based on sea level, you need to adjust your elevation to be with respect to the ground.