25 January 2005
Figure D-7 Completed Nonlinear Static Model
1) Assign each column that has to be removed into a separate group. For this
example, only one column was removed. It was assigned to group IC.
2) Assign similar members directly connected to the removed column into a
separate group. This will allow easy and efficient redesign if needed. For this
example, all girders connected to IC were assigned to group ICgird, all interior
beams connected to IC were assigned to group ICintbeam.
Define and Assign Hinge Properties.
1) Define new hinge property for each different hinge. Because the beam
sections have a different yield rotations, each beam section was defined
separately (W18x35H, W18x40H, W18x55H). Columns can be defined in the
same way; however, this example used SAP, which currently does not let the
user properly define PMM hinges (Axial-moment interaction hinges) manually.
Therefore, all column hinges are defined by FEMA 273, equation 5-4 as
2) Modify properties of each hinge to match the hinge properties in Table 4.2.2.
All beam sections were in the most compact section group [(bf)/(2*tf ) <
52/(Fy)1/2]. See Figure D-8 for an example of the input screens. All column
sections have PMM hinges.
3) Assign hinges to members. SAP uses relative locations, so all beams will
have beam hinges at relative locations 0, 0.5, and 1. Columns will have PMM
hinges at relative locations 0 and 1.