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SDPWS added an Example C4.3.4-3 that provides a derivation of first term of the deflection equation relating to End Chord Bending Deflection. This derivation assumes an equal number and size of end studs on either end of the segment. In Shearwalls you can enter different numbers of studs at each end, and there are circumstances that call for asymmetric stud packs.
Modelled after C4.3.4-3, we derived an equation for bending deflection with unequal numbers of end studs at each end, and applied it to those cases. The equation and its derivation is given in Asymmetric End Studs.
The value shown in the A column for end stud pack cross section when there are unequal end studs is the effective A in the new formulation.
The legend to the Deflection table has been modified to show this equation and the new definition of A.
Two columns have been added to the Shear line, Shear wall, and Opening Dimensions table to show the number of end studs at the end of the segment as input in Wall Input or Openings Input views.
These end studs are also needed for the new features Crushing Component of Hold-down Displacement (see below) and Design for Compression Forces. The end studs had been used to select hold-down device capacities from the database, but were not output to the program.,
Shearwalls has implemented a calculation of the crushing component of the hold-down displacement term of shear wall deflection based Example C4.3.4-2 that was added to the SDPWS. Previously a uniform crushing component was applied to the displacement of all hold-downs in the program.
In the Hold-down settings, the input for Crushing has been removed. The program no longer applies the value input there to the crushing.
The calculation of resistance to compressive stress perpendicular to the grain in the wall bottom plate under the end studs is described in Crushing.
A column has been added for the compression force C needed to calculate the crushing component. The force at the other end has been renamed Tension from Uplift.
The "extra' hold-down displacement components input in the Hold-down settings are no longer included with the "Crush" column, instead they have been added to "Shrink" column which is now called "Shrink + Extra". This is because the shrinkage component is similar to the "Extra" components in that they are constant with respect to applied shear force v.
The legend has been modified to explain the new forces, using new symbols, and to provide the crushing calculation.
The unfactored Fc⊥ value for the framing material of each wall group is now shown in the Framing Material table. Notes showing the Temperature factor Ct and In-service Moisture factor CM are shown if they are other than 1.0. A note giving the design code reference for the bearing area factor Cb is shown.
Two columns have been added to the Shear line, Shear wall, and Opening Dimensions table to show the number of end studs at the end of the segment as input in Wall Input or Openings Input views.
These end studs are also needed for the new features Bending Deflection with Unequal End Chords (see above) and Design for Compression Forces. The end studs had been used to select hold-down device capacities from the database, but were not output to the program
A Figure C4.4.3.4B was added to new example C4.3.4-2 showing beff as the appropriate value to use as the factor h/b used in the final term of the deflection equation to convert vertical hold-down displacement to rotational shear wall deflection due to overturning. Discussions with AWC confirmed that beff was the correct value to use despite segment length b being shown in the deflection equation.
The calculation of beff is also used for the overturning force, and was modified for this version.
A definition of beff showing the calculation was added to the legend of the Hold-down displacement and Deflection tables.