Diaphragm Basics - The Analysis of Irregular Shaped Structures - page 47

F i g u r e 2.21 Interior shear wall with shear panels added.

Assume that the nailing of the diaphragm sheathing to the truss is adequate to
transfer the required collector force into the truss and that all other nailing is in accor-
dance with the detail shown in configuration A.
The resulting gravity force applied to each end of each piece of flat blocking is 366 lb.
The deflected shape of the trusses shown in Fig. 2.18 suggests that the computer pro-
gram assumes that the capacity of the flat blocking and its connections to the trusses are
adequate, and therefore provide an interior support for the trusses. As with any com-
puter analysis, the results should be verified to validate the design.

Check the flat blocking
Assume 2 × 6 DF-Larch no. 2, F b = 900 psi NDS Table 4A

C f = 1.15 flat-use factor NDS Table 4A

C D = 1.15 snow load duration factor NDS Table 2.3.2

b ==

2

5515
6

.(.)

2

S = 206 . in

3

6

PL 0 731 2

4

. ( )

M == = 0 366 . ft-k here L = ′ 2

4

M () 12 0 366 12

206

. ( )

f

b =

= = 2 132 . ksi > 900 115 ( . ) ((. ) 115 = 1190 psiallow

S .