Using the "Don't Reduce Integrated M and V due to Sign Change" option

Design sections and span segments contain an option (checkbox) with the label "Don't reduce Integrated M and V due to Sign Change". If this option is selected, Concept will perform five integrations of the cross section forces for every loading and load pattern:

Standard Integration - this is as described in "Calculating the forces on the cross section".
Max Moment Integration - same as item 1, except that only elements that would increase the integrated bending moment value are considered.
Min Moment Integration - same as item 1, except that only elements that would decrease the integrated bending moment value are considered.
Max Shear Integration - same as item 1, except that only elements that would increase the integrated vertical shear value are considered.
Min Shear Integration - same as item 1, except that only elements that would decrease the integrated vertical shear value are considered.

The intent of this option is to allow for safe, conservative designs where cross sections include regions of moment (or shear) with opposite signs that cause the moment (or shear) recorded for the cross section to be less than that for a shorter sub- cross section.

The values from the above integrations may not be considered in certain circumstances:

Standard Integration - all values always considered.
Max Moment Integration - bending moment value considered if bending moment is same sign as bending moment in Standard Integration.
Min Moment Integration - bending moment value considered if bending moment is same sign as bending moment in Standard Integration.
Max Shear Integration - vertical shear value considered if vertical shear is same sign as vertical shear in Standard Integration.
Min Shear Integration - vertical shear value considered if vertical shear is same sign as vertical shear in Standard Integration.

When the "Don't reduce Integrated M and V due to Sign Change" option is selected, the design forces are always more conservative than when the option is not selected. This option should not be used without due consideration.

Note: These selective integrations are performed independently for each loading. Load(ing) Combinations cross section forces therefore may include (and exclude) forces from different elements in each loading. This adds to the conservatism of the option.

Note: The "Don't reduce Integrated M and V due to Sign Change" option is not used for combinations analyzed with zero-tension iterations.