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Important Note – These are descriptions to changes implemented in WoodWorks Shearwalls for version 9 and may not reflect current behavior.
Because of the need to add information for deflection design, the shearwalls materials table has been split into two tables, one for sheathing materials and one for framing materials.
For the framing materials table, only one line is needed for each wall design group, instead of the two needed for sheathing materials on each side of the wall. The fields that have been added are
A note has been added below the table saying
Check manufacturer requirements for stud size, grade, and specific gravity (G) for all shearwall hold- downs.
Columns have been added for the anchor bolt length and the length subject to shrinkage, as input in the Structure Input view.
A table has been added to show the components of vertical hold-down displacement da due to the main elongation, displacement, slippage, shrinkage, crush, and additional sources. It has the following fields.
The wall segment between openings is shown as e.g. B-3, 2 = second segment on Wall 3 on Shearline B.
E->W, N->S, etc. Can be “Both” if the data is identical in both directions because forces and hold-downs used are the same. In that case only one line is output instead of two.
The hold-down name from the database that is selected at the tension end of the segment. There is limited space for the name, so it may be truncated.
The hold-down force at that location, including force transferred from floors above, and including the dead, shear and overturning components. For seismic design it is the sum of the unfactored components for strength-level design.
This gives the displacement for hold-downs with combined elongation and slippage, the elongation otherwise.
Data appear in this column only for those hold-downs for which there is separate slippage and elongation.
The calculated displacement due to wood shrinkage. The moisture contents appear in the legend below, and the length subject to shrinkage on each level appear in the Story Information table.
The value of wood crushing plus any additional components entered in the hold-down settings appears in one column. Although this column usually holds the same value for all segments, it is possible that at some locations the crush is zero because there is no compression force at the usual compression end of the shearwall.
The total vertical displacement for each segment, or sum of the elongation, slippage, shrinkage, crush, and additional displacements, is output in a column.
The resulting horizontal in-plane segment deflection from the hold-downs, or da multiplied by the segment aspect ratio h/b, is output in a column. This value is then transferred to the Deflection table.
The legend spells out the calculations that are used to arrive at each value, giving the value of any needed data not in the table such as percent moisture content and steel modulus of elasticity.
Because SDPWS Table C4.2.2D for nail slip applies for lumber framing members with specific gravity of 0.5 or greater, a warning note appears below the table if any of the framing members that the hold-downs are connected to have specific gravity less than 0.5. Note that S-P-F materials have specific gravity less than 0.5.
The wall segment between openings is shown as e.g. B-3, 2 = second segment on Wall 3 on Shearline B.
The wall design group
E->W, N->S, etc. Can be “Both” if the data is identical in both directions because forces and hold-downs used are the same. In that case only one line is output instead of two.
Some of the columns ( shear deflection and nail slip) have different values for different sides of the wall. To calculate them, different v values for each side of the wall are used as well. Therefore for each segment, if it is a composite wall, there are two lines output.
Wall surfaces are output as they are in the shear table, as Int or Ext for perimeter walls, and 1 or 2 for interior walls.
The unfactored unit shear value on the segment ( that is, strength level shear for seismic design) is output. The proportion that goes into each side of the wall for composite walls is given.
This value depends on the distribution method input in the Design Settings, and when deflections are equalised, in many cases it can be zero. See .
This is a full-height segment for segmented walls, or the sum of such segments for perforated walls.
Although this does not change for all segments within a level, it is output in a column as it is integral to the calculations.
For the bending component, the following are output on the first of the two lines for the wall segment:
The calculated shear deflection is output on both lines for the wall segment. The legend shows the calculation.
The following values are shown for the nail slip:
This value is transferred from the Hold-down Displacement table, where the components of hold-down displacement are given.
Deflection from bending + shear + nail slip + hold-down, as per SDPWS C4.3.2-1.
Note that shear + nail slip should be the same for both sides of a composite wall, or else one side has zero force and the shear + nail slip for the other side is used. If his is not the case because the numerical procedure failed, the largest shear + nail slip is used.
The legend spells out the calculations that are used to arrive at each value, giving design code references and where to find data not in this table, e.g. the Stud modulus of elasticity in the Framing materials table.
Because SDPWS Table C4.2.2D for nail slip applies for lumber framing members with specific gravity of 0.5 or greater, a warning note appears below the table if any of the framing members for the walls have specific gravity less than 0.5. Note that S-P-F materials have specific gravity less than 0.5.
A table has been added to the program to show the storey drift calculations ASCE 7 equation 12.8-15 and the allowable storey drift from ASCE 7 Table 12.2-1. The allowable drift is shown for each level; the maximum storey drift for any shearwall on the level is shown on one line for each force direction below the allowable values.
The wall height h is shown for each building level, along with the storey height hsx for that level, which is the wall height plus the upper floor thickness.
The allowable drift Da calculated from ASCE 7 Table 12.2-1 is shown for each level only.
The values of the deflection amplification factor Cd from ASCE 7 Table 12.2-1, for the building system entered in the site dialog, and which can be overridden in the site dialog, are entered on each line. Note that the Cd values can be different for different force directions.
The importance factor I calculated from the Occupancy category entered in the sited dialog. This is the same for the entire structure, but is repeated in the table to show all variables for a calculation on the same line.
For each force direction on each level, the table shows the largest of the deflections on any shearline in the force direction, referred to as dxe in ASCE 7, as well as the line the maximum was on.
The program shows the maximum amplified deflection dx, calculated using ASCE 7 equation 12.8-15.
The program places an asterisk (*) beside any response ratio that is greater than 1.00. A note appears below the table as follows
A legend has been added explaining each column in the table.
The program has been change to allow for output of seismic results for each force direction. Previously this was not needed, as forces were always the same in both directions. Because hold-downs selected and hold-down forces can vary in opposite directions, and these affect deflection and thus load distribution, results can be different in opposing directions.
To all the above tables a legend has been added to the table or an existing legend improved such that it shows detailed information pertaining to each column on a separate line.
For all the above tables, items have been added to the Show menu and the Display checkboxes in the Options settings that allow you to turn off the tables in the screen display and in the printed output, to reduce the volume of output, similar to all other tables.
The force on each shearwall segment arising from the distribution of forces described in B: 3 above are depicted by small arrows at the top of the wall at each segment, with the force in pounds on that segment shown.
The shear flow depicted at the bottom of elevation view is now much more likely to show different forces for each segment. This was previously only due to the perforation wall factor or seismic height to width factor.