Theoretical predictions regarding the ultimate resistance of slender plate girders to applied shear
loading, based on existing theories and formulas, show close correlation with the test data
presented. When a plate girder is subjected to a bending moment in addition to shear, the
determination of the ultimate resistance becomes more complex. Herein, an interaction formula
for the ultimate resistance of slender plate girders to combined bending and shear loading is
proposed, which shows satisfactory correlation with the available theories and which is acceptable
for practical purposes. The proposed interaction equation covers web panel aspect ratios, bw=dw,
from 1 to 2 and slender ratios, dw=tw, from 150 to 300.