Diaphragms With End Horizontal Offsets - The Analysis of Irregular Shaped Structures - page 103

F i g u r e 3.12 Transverse collector force diagrams.

line 2C, the collector along grid line 2 from B to C has a uniform net shear of +400 plf.
The force at grid line 2B is equal to
F 2 = 400 15 () = 6000 lb

B

The direction of the transfer shear shows that the member is in tension. The net
shears on each side of grid line 2 between A and B are applied in opposite directions
and are to be subtracted from each other. The resulting direction of the transfer shear
is opposite to that of the drag member between B and C, which also indicates tension.
Continuing from grid line 2B to grid line A, the force in the collector is equal to

F A = 6000 - ( 214 3429 35 . - .)() = 0 lb

Therefore the force diagram closes.
The collector along grid line 3 from B to C has a net shear of +320 plf on the left side
of the member and a unit shear of +70 plf on the right side. The transfer shears act in
opposite directions and are to be subtracted from each other. The force in the collector
at grid line 3B is equal to

F 3 = ( 320 - 70 15 )() = 3750 lb compression

B