Path A-D-G-K Length and Net Area
The path length, in this case, is the plate width (12") less four EFFECTIVE HOLE DIAMETERS plus two STAGGERS:
EFFECTIVE HOLE DIAMETER = bolt dia. + 1/16" for std hole + 1/16" damage allowance
One stagger is between holes A and D and has a pitch (s) of 3" and a gage (g) of 3"
The other stagger is between holes G and K and has a pitch (s) of 3" and a gage (g) of 3"
Path Length = 12" - (4 hole diameters)*(3/4" + 1/8") + (3")2/(4*3") + (3")2/(4*3") = 10.00 inches
The net area equals the path length times the plate thickness:
Net Area = (10.00")(.375") = 3.75 in2
Note that this is the smallest, and hence the controlling, valid path for this plate.
Note that there are two identical plates pulling in the same direction, so if you are computing the capacity of the connection, the net area is twice the net area of one plate. The following figure illustrates the critical tensile rupture surface.