Torsional Analysis in Log File

Important Note – These are descriptions to changes implemented in WoodWorks Shearwalls for version 10.0 and may not reflect current behavior

Significant new information and reformatting of existing information for readability, as well as corrections to inaccuracies, have been made in the torsional analysis section of the log file.

1. Reformatting

   Blank lines and header bars have been inserted in the file to delineate sections for readability.

2. Unfactored Forces

   A note has been added under the Rigid Diaphragm title explaining that the forces shown are unfactored.

3. Vertical Accumulation of Rigid Diaphragm Forces

   A note has been added to the log file explaining that for rigid diaphragms, that loads on the current level plus unfactored forces from the levels above are used in the rigid diaphragm analysis, to avoid compounding torsional effect.

4. Building Dimension B

   The building dimension perpendicular to load for torsional analysis of ASCE wind loading in the log file now uses the symbol B instead of D in conformance with ASCE 7 27.4-8

5. Inherent Eccentricity

   In the Log file, the phrase “Torsional Eccentricity” referring to the eccentricity of the building structure has been changed to “Inherent Eccentricity” in conformance with the ASCE nomenclature from 12.8.4.1. Although this is from the seismic design section, it has been applied to both wind and seismic torsional calculation output in the log file.

6. Seismic Force Direction Identifier

   For seismic forces in the east west direction, the program uses the subscript x when it should use y for eccentricity and centre of rigidity.

7. Wind Load Accidental Eccentricity Line

   For all heights wind design, line giving the accidental eccentricity was unnecessarily repeated and in an place inconsistent with other output

8. Seismic Load Accidental Eccentricity Line

   The line giving the “torsional” (now “Inherent”) eccentricity was missing for seismic design.

9. Negative Sign in Torsion Equation

   For wind loads, the equations for torsion due to the negative accidental eccentricity had a negative sign in front of the force F, i.e. T- = - F *(etx - eax). It is not correct and has been removed.

10. Rigid vs. Flexible structure Accidental eccentricity

    The log file now differentiates between flexible and rigid structures (dynamic vs static analysis) for accidental eccentricity output. Previously it was outputting the rigid structure accidental eccentricity for flexible structures instead of the eccentricity you input in the Site Dialog.