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Important Note – These are descriptions to changes implemented in WoodWorks Shearwalls for version 9.3 and may not reflect current program behaviour.
The following problems in determining the value of Nu used in O86-09 9.7.1.1 for the anchorage component of shearwall deflection, when calculating embedment strength f1 of the sheathing in 10.9.4.2, were corrected:
The program erroneously used the value of the dead load component of the hold-down force in N in place of the nail diameter in mm.
If there are no dead loads at the hold-down location, or dead loads less than or just a little more than 10 N, then the program would calculate the wrong f1 value in the yield mode equations, and non-conservatively so. If there are dead loads significantly greater than 10N (which is very small), then the program would not include the yield mode terms that include f1 when determining the hold-down values. That is, it would use yield mode b only. This will also be a non-conservative error in most cases.
This bug interacted with bug 2991, below, which results in very large anchorage deflections, so that if there are significant dead loads, this bug counteracted the other bug so that together they create unreliable results.
In determining the value of Nu used in O86-09 9.7.1.1 for the anchorage component of shearwall deflection, when calculating embedment strength f1 of the sheathing in 10.9.4.2, the program used sheathing specific gravity values 1/10 of those listed in O86-09 10.9.4.2. They were G = 0.049 for DFP and 0.042 for CSP and OSB ,as opposed to 0.49 and 0.42, respectively. This caused anchorage deflections to be roughly order of magnitude larger than they should be, however this varied widely from shearwall to shearwall. This error could also cause forces to the individual shearlines to be distributed to the segments incorrectly in an unpredictable way
This bug interacted with bug 2986, above, which caused the f1 value never to govern if there were significant dead loads, so this bug would have no additional effect in that case. If there are dead loads, this bug counteracted the other bug so that together they create unreliable results.
When shearwall capacity is used as the design force for hold-down design, either via the design settings or because it is required due to seismic irregularities, this value was also used to determine the hold-down component of shearwall deflection. As this is not the intent of the use of shearwall capacity to ensure sufficient hold-down strength, the calculation for deflection now always uses applied force to determine hold-down displacement, regardless of the design setting for hold-down forces or the existence of irregularities.
After determining the structural irregularities, the program if necessary changes the hold-down method to capacity and then recalculates deflections, redistributes loads based on these deflections, and sometimes redesigns the structure. However, because hold-down deflections were based on shearwall capacity, reconfigured building may not have the same irregularities as before, but the program does not recalculate them. It was therefore possible that irregularities shown in the output and those that apply to the structure did not match.
In particular, the deflections used to determine Bx, the torsional sensitivity, were not the same as the ones that are shown in the output for the redesigned building. It could even happen that the program determined the building was torsionally irregular, changed the hold-down setting, and the redesigned building was no longer torsionally irregular.
This situation can no longer occur, because the change in hold-down method to being capacity-based no longer affects deflections.
When a non-standard nail diameter was entered, the program ignored it and used the diameter of a standard nail with the input length. The standard diameter appeared in the Sheathing Materials table, and the shear capacity reduction factor in A9.5.1.2 was not applied. When deselecting the wall then reselecting it, the standard diameter would reappear.
Non standard nails are now called "power driven" nails, and function as intended. The program uses the nail length and nail diameter in the new design equations for shearwall shear resistance based on nail strength from O86-14 11.5.1, and the nail diameter in the design procedure from A9.5.1.2 when O86-09 is selected.
The program now outputs a Storey Drift for wind loads, showing the maximum deflection of any shearline for every storey and direction, and compares it with the limit in NBC 4.1.3.5 3) of 1/500 of storey height. Note that sentence 4) of this 4.1.3.5 exempts industrial buildings and sheds, however Shearwalls does not take this into account and outputs a storey drift table for all structures. Please disregard the table for industrial buildings and sheds.
A failure for wind storey drift is output in the Design Summary.
The following problems related to standard walls, design groups, and the interaction between them, were corrected
Upon exiting the program, it saved the changes made to Standard Walls that occur when changes are made to walls in the structure while "Design in Group" is checked. Therefore, changes you might inadvertently make while modifying walls could affect the standard walls used for future sessions.
Now, the program asks you whether you want to save the standard walls when exiting standard wall mode and when exiting the program. When exiting the program this prompt only appears if a wall has ever been modified in this way.
Previously, the program saved standard the standard wall file that is used for future sessions when saving a new standard wall, deleting a standard wall, leaving standard wall mode, or selecting a new standard wall in the drop-down list in standard wall mode. It now only saves the standard walls when leaving standard wall mode and when exiting the program.
The Design in Group feature proved to be difficult to implement for a wall that had been created input of walls in the structure rather than via Standard Wall input, because there is no standard wall associated with the wall and design groups are accomplished through standard walls.
For this reason, the program now allows you to create standard walls from regular walls as follows:
When clicking "Edit Standard Walls" while there is a wall selected which does not match any standard wall, the program now asks you if you wish to create a standard wall based on the selected wall. If you create a standard wall in this way, the Design as Group setting is checked for the standard wall and the Design in Group checked for the selected wall.
This feature enhances the program usability in general, similar to the creation of a new font style in a word processor using the font attributes of the selected text.
When you unchecked the Design as Group checkbox in Standard Wall mode, the change is not retained when selecting another standard wall or exiting the box, making it impossible to specify that standard walls are not designed as a group.
Sometimes, after selecting a standard wall that is not designed as a group, the standard wall name goes blank in the input field rather than showing the selected standard wall. This has been corrected.
This happened most often when multiple walls were selected and has been corrected. .
When design as group is activated for a standard wall that has the same materials as another standard wall group, the program sometimes assigned individual shearwalls to the wrong design group, that is, to a design group for a standard wall group other than the one designated for that wall.
The following problems relating the nail deformation en value from CSA O86-09 Table A.9.7 have been corrected for when CSA O96-09 is selected as the design code. They do not affect program behavior when O86-14 is selected.
When a nail size other than the smallest one in the table was chosen, the program used an en from the next smallest standard nail size rather than the nail size selected. This resulted in a greater than expected nail slippage component of deflection. This problem did not occur when a non-standard nail intermediate between two standard sizes was entered; in that case the program correctly selected the lower value.
If a you entered a nail diameter less than 2.84, the lowest value in the table, the program issued a warning message under the Deflection table in the Design Results about loads per nail being over the highest allowable, even if the loads were within range. The en value used was for the largest diameter and highest loading.
The program now disallows selection of nails less than 2.84 mm in diameter if deflection analysis is turned on.
If the load per nail was greater than the highest allowable, the program used highest nail slip value for the 3.66 mm diameter nails, or 0.98 mm, not the deflection value for the nail that was selected. As this is the largest diameter, which has the lowest deflection, it creates non-conservative deflections for all other diameters.
Note that a warning message is still issued in this circumstance because even though the en is now for the correct nail size. it corresponds to loading less than what is actually on the nail.
In the Design Summary, the program previously reported a list of items that were not included among the checks being summarized, even though the program made those checks in the course of seismic design. Now, these checks are reported as having passed or failed. These checks are:
Percentage gypsum wallboard from O86-14 11.8.8 or O86-09 9.5.4
Storey drift from NBC 4.1.8.13.(3) and O86-14 11.8.8.
Seismic Irregularities from NBC 4.1.8.6
Over-capacity ratio from O86-14 11.8.3.2 or O86-09 9.8.3.2
The following problems relate to the message box that appears when the Force Modification factor Rd selected in the Site dialog is not the one appropriate for the materials used, and have been corrected
The message box during load generation indicating that an Rd factor of more than 2 should not be used when there are gypsum materials in the structure was not appearing when all the walls with gypsum sheathing had both sides sheathed with gypsum. This has been corrected.
While generating loads for shearwalls with gypsum on one side and the Rd set to 2, the value appropriate to gypsum walls, with the setting for ignoring gypsum unchecked, the program nonetheless issued a message that this setting was active and the offering to either change the Rd value or uncheck the setting.
If you selected "No" to uncheck the setting, the setting remained unchecked program continued to generate loads with the correct Rd value.
The following problems related to the Percentage Storey Shear Resisted by Gypsum Wallboard table used to implement O86-09 Table 9.5.4 have been corrected.
The table no longer appears if there is no gypsum wallboard on the structure
When calculating gypsum and wood capacity only one force direction case was considered: the east-to-west or north-to-south case. Therefore, when the table indicated was displaying results from the south or west direction, it was actually displaying the results for the opposite direction. The program now calculates the percentage shear force in each direction independently.
Upon designing walls with OSB sheathing with unknown panel marking, sheathing thickness and non-standard nails selected, an "Improper Argument" error message appeared and an incorrect Jn factor was calculated, invalidating design.
This has been corrected.
Elevation view was sometimes showing the FAILED design message for interior walls even though the walls passed design. This could happen when you had selected to allow anchorages rather than hold-downs on the wall, and the design setting was set to allow the program to "over-ride" the use of anchorages if necessary and impose hold-downs. This has been corrected.
In the storey drift table, the program used to output Both to indicate, for example that the results apply to both E->W and W->E. However, this table also includes results from the other orientation, in this case N->S and S->N, so it was unclear what Both referred to. The program now says e.g. E<->W when indicating the results apply to both directions rather than Both.
The notation (%) has been added to the data group label for the Moisture Conditions settings, to indicate that the numbers shown are percentage moisture content.
Adjacent to the input of Moisture Content in the Design Settings, the program now indicates whether the value is dry, wet, or green (O86-14), or dry, wet, seasoned, or unseasoned (O86-09). This is now also indicated in the Design Results echo of the Design Settings.
For some cases in which not all of the wall design groups are standard walls, and when only one of rigid or flexible design is performed, the program prints out an extra line for each C&C result in the output table with 0 load and 0 capacity, additional one wall design groups not related to any actual walls are created with, with 0 load and 0 capacity. These problems have been corrected
The line in the plan view legend explaining the red color for failed walls now indicates that it is a "Capacity" failure, to clarify that other types of failures now reported in the Design Summary are not highlighted.