Activates the Class 1 flexibility calculations. By default, this setting is False.
The appearance of this parameter in the configuration file will completely change the modeling of intersections in the analysis. For intersections not satisfying the reduced branch rules that d/D £ 0.5 and that D/T £100, the branch will start at the surface of the header pipe. A perfectly rigid junction between the centerline of the header and surface will be formed automatically by CAESAR II using the element offset calculations. SIFs act at the surface point for the branch. When the reduced branch rules are satisfied, the local flexibility of the header is also inserted at this surface point. Intersections not satisfying the reduced intersection rules will be stiffer and carry more loads, while intersections satisfying the reduced intersection rules will be more flexible and will carry less load. All changes to the model are completely transparent to the user. In systems where the intersection flexibility is a major component of the overall system stiffness, you are urged to run the analysis both with and without the Class 1 Branch Flexibility active to determine the effect of this modeling on the analysis.
When B31J is enabled (through Apply B31J SIFs and Flexibilities), the software ignores this configuration option.