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Important Note – These are descriptions to changes implemented in WoodWorks Shearwalls for version 9 and may not reflect current behavior.
The bottom of generated wind area loads on the upper portion of walls was not midway up the wall, instead midway plus ½ the floor depth. This created a higher z-value used for the evaluation of the exposure coefficient Kz and the topographic factor Kzt. The effect was conservative and small, creating wind loads at most 3% too heavy.
Automatically generated area loads on the lower half of walls are given a vertical tributary width that is derived from the upper half of the storey, so it includes the joist depth of the storey above when it shouldn’t. These incorrect widths are shown in the load lists in the load input screen and Design Results.
The incorrect width is used in creating the load intensity shown in these lists, so that the total load on the wall segment remains the same as if the correct tributary width was used. The line load created on the diaphragm and shown in plan view is also correct, so this problem has no impact on force generation or design.
The redundancy (ρ) factor calculations for ASCE 12.3.4.2 were not including the user-applied loads and shearline forces in its base shear calculations. This caused the rho factor to be more likely to be set to 1.3 instead of 1.0 in this case, possibly causing conservative forces to be created.
Now, the user applied loads and shearline forces are added to the base shear determined by the load generation procedure. As user-applied shearline forces are factored, these forces are first unfactored before being added to the base shear.
For version 8.21 of the software only, the anchorage force t for perforated walls from SDPWS 4.3.6.4.1 was not creating anchorage hold-down forces at the opening ends for that portion of an anchorage force that is distributed from an upper storey wall to an opening on the lower story.
The anchorage force uplift (t) that is created for perforated walls as per SDPWS 4.3.6.4.1 was twice as large as it should be for seismic design. This also sometimes created uplift (t) point load hold-down forces that were twice as large as they should be.
Upon generating loads, the program issues a warning if you have selected a response modification factor R for a particular direction that is not the one for the building system in use, according ASCE 7 12.2-1, for example if a value of 6.5 is used in the presence of gypsum wallboard which should have an R value of 2.5. According to the response, the program changes the R value to the appropriate one, or sets the “Ignore non-wood panels for all walls” setting, or cancels load generation.
In making this warning, the program considers the effect of the setting “Ignore non-wood-panel contribution for all walls”, that is, if it is set, it does not issue the warning and allows the higher value of R. However, it was not considering the effect of the Ignore non-wood panels when combined with structural wood panels setting, in the case that the gypsum materials were always combined with wood panels in the direction in question. In these cases it used to issue the warning and impose the lower value of R, but now the warning does not appear and the higher value of R is allowed.
Similarly, the program failed to deliver a message that a higher R value was possible when the R value was set to 2.5, but could be 6.5 for this reason.
Note that in these cases, the correct behaviour could have been achieved by setting the Ignore .. for all walls, setting, which is equivalent to Ignore … when combined.. setting when there are no walls that are totally non-wood-panels ( e.g. gypsum on both sides).
The default response modification factor R that comes with new installations of Shearwalls now has a response modification factor of 2.0 rather than 6.5. This is because the default standard walls that come with Shearwalls have gypsum materials. Previously, the default was 6.5, which caused a warning message to appear for load generation with the default Shearwalls configuration.