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Walls can be designated as one of four types, non-shear walls, segmented walls, perforated walls, or force-transfer walls. These types refer to the design methodology employed and do not reflect physical characteristics of the wall itself aside from the placement of hold-downs and force-transfer straps and blocking. All four are permitted on the same structure, in fact on the same shear line.
Segmented Walls
Traditional shear wall design, where hold-downs are required at the ends of all full-height segments, and segments containing openings are neglected when distributing shear forces, so that these segments do not contribute to the shear wall resistance. Segments that are too narrow according to rules in SDPWS Table 4.3.4 also do not draw force or contribute to shear wall resistance.
These walls appear solid in Plan View, however narrow segments within them are shown as as hollow.
Perforated Walls
This approach requires hold-downs at the wall ends only, but reduces the shear capacity by a perforation factor (opening coefficient) based on opening size, and increases the design hold-down and drag strut forces by the inverse of that factor. Openings and narrow segments are neglected when determining the effective length of the wall for shear force distribution, so that the average shear force on all segments is the same as a segmented wall of the same proportions, however, the shear force on each segment of the perforated wall is the same and the wall is analyzed as a unit.
Any non-full-height segment that occurs at the end of the wall, and the opening next to it, is ignored when deciding where to place hold-downs and when calculating the perforation factor. Thus perforated walls are pared down to their extent between the extreme full height sheathing segments when used in force distribution, design and deflection routines.
These walls appear with diagonal hatching in Plan View.
Refer to the following for more details:
Deflection of Perforated Shear Walls
Perforated Shear Wall Hold-down Forces
Drag Strut Forces in Perforated Walls
for more details.
Force-transfer Walls
This approach also requires hold-downs at wall ends only, but segments with openings are included in the distribution of shear force and contribute to wall resistance. Shear force is transferred around openings by steel straps and blocking, and distinct shear stresses are developed in each shear wall "pier", rectangular areas beside above and below openings, or above and below other piers.
Force transfer walls require full-height wall segments at each end, 12" foot of material above and below openings (i.e. no doors), a minimum segment width of 18" (blocked) or 2 feet (unblocked). and for each pier to satisfy the height-to-width rules in SDPWS Table 4.2.4. Shearwalls rejects force-transfer walls not conforming to these restrictions when you try to input them.
These walls appear with square hatching in Plan View
Refer to the following for more details:
Non-shearwalls
Non-shear walls are a portion of the shear line that is not intended to resist shear forces. The program ignores non-shear walls when distributing shear forces within the shear lines, and ignores shear lines composed entirely of non-shear walls when distributing lateral loads to the shear lines. Exterior non-shear walls are, however, designed for out-of-plane wind loads.
A drag strut is required across non-shear walls as if they were a gap in the shear line.
These walls appear hollow on the screen.