Structural Iteration for Redundancy Factor

Important Note – These are descriptions to changes implemented in WoodWorks Shearwalls for version 9 and may not reflect current behavior.

The program still performs two designs of the structure for the purposes of calculating r, however this is now part of a larger design sequence that includes a third run for final design check.

1. Initial Value

   The value on the initial iteration has been changed to 1.0 from 1.3 for two reasons:

   1. Efficiency

      Experience has shown that the vast majority of buildings have r = 1, so that a second iteration is not necessary if r is set to one in most cases..

   2. Design Check

      Now that a third iteration to check the designed walls is done, setting the initial value to 1 avoids the circumstance that a 1.3 value on the first iteration is set to 1.0 on the second, during which walls are designed that require r = 1.3 , and loads generated on the design check run could then cause the walls to fail.

      When 1.0 is the initial value, and the second iteration uses 1.3, then walls can be designed that only require a rho of 1.0. The walls will then be conservative for loads generated on the third, design check run.

2. Load Distribution

   The r value used when only load distribution, not design, is performed has been changed from 1.3 to 1.0. This reduces the likelihood of loads for the designed structure differ from those from on the that previously appeared when loads were distributed for undesigned walls.