Diaphragms With End Horizontal Offsets - The Analysis of Irregular Shaped Structures - page 129

F =

F =

F =

F =

F =

F i g u r e 3.26 Transverse collector force diagrams.

This force is equal and opposite to the force on the opposite side of grid line B.
Therefore the force diagram closes to zero, and the collector is in compression. The net
shears transferred into the collector at grid line 3 from 3A to 3B are 23.95-15.1 = +8.85
plf and 40.9-32.05 = +8.85 plf, respectively, indicating that there is a uniform net shear.
Starting at grid line A, the force at grid line 3B is equal to

F 3 = 88535 . () = 309 8 . lb tension

B

The net shears transferred into the collector at grid line 3B to 3C are 45.1-24.4 =
+20.66 plf and 15.1 + 5.56 = +20.66 plf, respectively, again indicating a uniform shear. The
force at grid line 3B is equal to

F 3

= 20 66 15 . () = 309 9 . lb compression

B

Determination of longitudinal collector/chord forces (see Fig. 3.27): The force in the strut at
grid line B has already been determined up to grid line 2. The shears transferred above