Hi,

I have a doubt in my mind regarding susatined load cases.

Generaly we have refferd SUSTAINED load case with W+P1.

But in my new project there are two separate SUSTAINED LOAD CASES are suggested

COLD SUSTAINED
HOT SUSTAINED

Please any one clear my doubt why there are 2 separate sustained (Hot & Cold) load cases required

The Sustained load case evaluates the primary (force based) stresses in the system. But, in what "state" should the evaluation be made (operating, shut down, or something else)? If you only have linear boundary conditions, this becomes a moot point because these "states" are all the same as far as primary stresses are concerned.

However, in a system with varying boundary conditions, there is a weight redistribution between states, therefore you can have different primary stress states. Hence the need for the cold and hot sustained evaluation.

Read the write up in Chapter 6 of the Technical Reference Manual for additional details.

Physical we have allways in hot case other pipeshape as in cold case.
Thats why we have allways small different weight results (hot/cold).

ACTUALLY ITS DIFFERENCE IS THE TIME WHEN THE SUSTAINED IS APPLIED.
AS WHAT I'VED LEARNED, HOT SUSTAINED CAN BE CALLED IN WHICH THE APPLICATION OF WEIGHT AND PRESSURE IS AT EXPANDED CONDITION. IN OTHER WORDS, DURING OPERATING CONDITION. COLD SUSTAINED CAN BE CALLED WHEN WEIGHT AND PRESSURE ARE APPLIED IN NO TEMPERATURE INVOLVED.
CONSIDER THE FOLLOWING LOAD CASES AS AN EXAMPLE:

DEFAULT
W+P1+T1(OPE)
W+P1(SUS)
L1-L2(EXP)

NEW
W+P1+T1(OPE)
W+P1(SUS) THIS IS COLD SUSTAINED
T1(EXP)
L1-L2(EXP)
L1-L3(SUS) THIS IS HOT SUSTAINED


REGARDS,

NALD