October 18, 2018
Updates to Wood Wall Aspect Ratio Limits in RISA-3D
With the initial implementation of wood wall design in RISA-3D, the wall aspect ratio was calculated as the full height of the wall divided by the width of the region.This was intended to accommodate balloon framed multi-story walls that were drawn as one continuous wall stack. With recent publications of the ANSI/AWC SDPWS, it has been made clear that the aspect ratio should rather be taken on a floor-by-floor basis.
In RISA-3D v17.0, the aspect ratio for walls will now be calculated based on the individual regions height. The below example shows the differences between the wall height and region height of a multi-story wall.