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The deflection of the entire force transfer wall is calculated as a unit as follows:
Reduced Segment Height
In this method, the deflection due to the shear force in the central pier is calculated on each wall segment between openings or openings and wall end, but assuming that the height of all but one of the segments is the height of the central pier plus the top pier only, i.e., the bottom pier is ignored. The one segment that is still considered to be full height is at the far end of the wall from the force direction.
Shear Force in Segments
The unit shear force v used for the calculation of segment deflection is the force in the central pier adjacent to openings, determined through force-transfer shear force distribution to piers.
Averaging of Segment Deflections
The analysis is done in both force directions using the same wall shear force, then all the deflections from the segments in each direction are averaged to arrive at the deflection of the entire wall; i.e. if there are n segments, 2n segment deflections are averaged.
That is, if E->W wind loads are different than W->E loads, due to for example a monoslope roof, then for the E->W force direction, the E->W force is used for both E->W and W->E directions, then all the deflections are averaged. The same thing is done again for the W->E force direction using W->E loads.
Components of Deflection Equation
The calculation of the shear, bending and nail slip components in the equations for deflection uses the reduced segment height h. The shear and nail slip terms are linear in h; the bending term is proportional to h3.
Refer to Hold-down Displacement Component for the calculation of the hold-down component of deflection.