Re: an question

Hi Balaji,

Your question is regarding the stress analysis of piping using computer software :

IS THERE ANY DIFFERENCE OF BEHVAOUIR OF A PIPING SYSTEM WHILE SEEN IN OPERATING CONDITIONS AND EXPANSION CONDITIONS? SAY IF THE DESIGN TEMPERATURE IS 400 C
THE ANALYSIS SOFTWARE CALCULATES LOADS,
THE LOAD FROM OPERATING VARIES WITH LOAD FROM EXPANSION,WHY SO? AT WHAT TEMPERATURE IS THE LOADS BEING CALCULATED ,CONSIDERING EXPANSION AND OPERATING CRITERIA? IF MY UNDERSTANDING IS RIGHT,THAT OPERATING AND EXPANSION ARE ONE ANOTHER THE SAME. NO, Operating and Expansion are the not the same load cases. I think you are more concern with the interpretation of output that you get from the analysis. The expansion load case is the effect of temperature alone. When we combine the sustained loads with expansion loads, we get the operating load case. That means the solver calculates the forces, displacements and stresses in operating and sustained load case. As per code the expansion stress is the difference of stress in max (or min) metal temperature condition and the installation metal condition. Thats why the expansion stresses are calculated as the algebraic difference of the stresses in operating load case and sustained load case. So now you need to see the output as below:

Stress checking:
1. Sustained Load case
2. Expansion Load case

Load & Displacement checking:
1. Sustained Load case
2. Operating Load case

After running the analysis you need to check the sustained stresses in the operating condition as well (by taking the support configuration from operating load case).

I think I have cleared your doubts in someway, Kaustubh Received on Wed May 15 23:26:00 2002