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According to all design codes, this component is calculated as the product of the shear line design shear and wall height. It it is constant along a shear line in the case that shear is distributed according to wall capacity and the walls are all constructed from similar materials; otherwise forces can be different along the shear line. For perforated shear walls, the hold-down force is also factored by the reciprocal of the opening coefficient.
Separate shear overturning components and separate combined holddown forces are generated for wind loads and seismic loads,in each direction, and for the rigid and flexible methods, so that eight different hold-down design cases are calculated.
Applied Shear vs Shear Capacity
A Design Setting permits you to specify which shear value to use, the induced shear v or the shear wall's capacity.
SDPWS 4.3.6.4.1 mandates use of applied load (nduced shear).
The "shear wall capacity" option is included because some seismic designers believe that the lateral-force resisting system should be designed on a capacity basis requiring the ultimate capacity of the hold-down to equal or exceed the ultimate capacity of the shear wall rather than the induced shear. Also, the ASCE 7 requires that hold-down connections to load bearing members such as sill beams be based on shear wall capacity,
Note that the perforated wall shear wall capacity referred to here has not been reduced by the opening coefficient Co - perforated shear wall theory assumes that the wall segments at the start and end of the shear wall reach their full (Co = 1) capacity.