Dear Mr. Richard,

In ASME B31.1 2007 Edition Sec 104.8.3 Mc = Resultant moment loading range due to reference displacement load range, N-mm (Ambient to Normal Operating range)

I wanted to know in cases where we have 2 systems connected to one another and both are being handled by seperate groups. We use displacement boundary conditions at the terminal point location specified by the other group for our system analysis. Displacement values specified by the other group change at our terminal point connection (4 cases were given based on operating condition of their system )based on change in operating conditions of the other system. We have analyzed our system for Expansion stresses for each seperate condition for which we received the displacement values at the terminal point.

For each Expansion stress case analyzed, Caesar II calculates Mc values at each node location i.e. Mc(1) corresponding to Expansion stress case 1, Mc(2) corresponding to Expansion stress case 2 and so on for the 4 cases. Expansion stresses for these 4 individual and seperate cases have been checked and are within SA values.

Resultant moment loading is calculated for each case but how to capture the range as terminal pint conditions change with each Operating case as required by ASME B31.1

Thanks and Regards

Benoy

The first thing to recognize is that you're not seeing the interaction of the two systems. For example, are the displacements of the other system that are being provided to you accurate (i.e. the same) as if both systems were modeled together. If your system affects the first, there will be some inaccuracy in those displacements.

I presume you have something like this:

1) W+T1+D1+... (OPE1)
2) W+T2+D2+... (OPE2)
3) W+T3+D3+... (OPE3)
4) W+T4+D4+... (OPE4)
5) W+P... (SUS)

So you could setup the expansion ranges as:

6) L1-L5
7) L2-L5
8) L3-L5
9) L4-L5

as well as

10) L1-L2
11) L1-L3
12) L1-L4
13) L2-L3
14) L2-L4
15) L3-L4

These range cases would consisder the varying displacements at your terminal points.