Purpose: Used to enhance the efficiency of girder design generation in Line Girder Design Projects. (Not applicable to Girder System Projects.)
--> Given in line girder design input
An optional list of approximate relative moments of inertia by web section for line girder design. This data can be used to reduce the possibility that the actual design, as carried out following a preliminary indeterminate analysis, will redistribute internal forces enough to cause stress violations when an analysis with actual stiffness subsequently is carried out. Default ratios are 1.0, i.e., uniform stiffness along the entire length is assumed for the preliminary analysis.