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Iteration for Redundancy Factor and Torsional Amplification Factor
If the redundancy factor r from ASCE 7 12.3.4 is set in the Site Information dialog box to be calculated by the program, the program sets r to 1.0. For rigid diaphragm analysis it also sets the torsional amplification factor Ax from 12.8.4.3 on each level to 1.0. It then performs a design for the whole structure. It then calculates r and Ax.
Note that if you have entered you own value for r in the SIte dialog, and you have not selected rigid diaphragm analysis, then the program does not do the extra iteration for r and Ax.
Wall Design Iteration
If the r value for the designed walls is then determined to be 1.3 or any of the Ax values are is other than 1.0 , another iteration is performed with shear line forces factored by r = 1.3 and Ax.
It is then possible that the walls that are designed on the second iteration only require a r of 1.0. The walls will then be conservative for loads generated on the third, design check run. This is unavoidable, as otherwise the program would oscillate between r = 1.0 and r = 1.3 solutions.
Note that the great majority of buildings have have r = 1.0.
The r value used when only load distribution, not design, is performed is 1.0.