Indicates use of a liberal stress allowable. Conservative formulation of the allowable expansion stress range for many codes in CAESAR II is calculated from:
f ( 1.25 Sc + .25 Sh )
When select this option, the difference between Sh and Sl, provided Sh > Sl, is added to the term inside the parenthesis. That is:
SA(Liberal) = f[ 1.25 Sc + .25 Sh + ( Sh - Sl) ]
The liberal expression is only used when there is at least one sustained stress case in the load set. If there is more than one sustained stress case in a single problem, then the largest of Sl, considering all sustained cases for any single element end, is chosen to subtract from Sh. Because the sustained stress varies from one pipe to another, the allowable expansion stress also varies.
By default, CAESAR II uses the liberal stress allowable setting in the configuration file in its computation of the expansion stress allowable. New models are created using this configuration setting. If you do not want to use this default setting for calculating the expansion, clear this check box.