25 January 2005
Figure C-5 Nonlinear Hinge Definition
Μrel = hinge moment (defined relative to yield moment)
θ = hinge rotation (defined as absolute rotation)
Table C-3 Nonlinear Hinge Properties (absolute rotation in radians)
0.0523 0.01 0.0525 0.01 0.055
*If designer is using SAP, moment hinge criteria for concrete columns controlled by
flexure should be derived from Table 9-7 of ATC-40; "Seismic Evaluation and
Retrofit of Concrete Buildings."
ALTERNATE PATH ANALYSIS.
The software used and screen shots depicted for this example was SAP
2000NL. The details of this example can be generally applied in any structural software
capable of nonlinear static analysis. The "Staged Construction" option in SAP was used
to ensure proper redistribution of loads upon member removal. Comparable software
should also have the capability of load redistribution, or loads must be redistributed
manually prior to analysis.
Develop Preliminary Model.
Build, analyze, and design model as described in part 1 of this example. See
Figure C-6 for a concept of how the model should look in SAP.