An axial load P is applied to the 1.75 in. by 0.75 in. rectangular bar shown in Figure P1.37. Determine the normal stress perpendicular to plane AB and the shear stress parallel to plane AB if the bar is subjected to an axial load of P = 18 kips.
An axial load P is applied to the 1.75 in. by 0.75 in. rectangular bar shown in Figure P1.37. Determine the normal stress perpendicular to plane AB and the shear stress parallel to plane AB if the bar is subjected to an axial load of P = 18 kips.
The angle θ for the inclined plane is 60°. The normal force N perpendicular to plane AB is found from
N=Pcosθ=(18 kips )cos60∘=9.0 kipsand the shear force V parallel to plane AB is
V=Psinθ=(18 kips )sin60∘=15.5885 kipsThe cross-sectional area of the bar is (1.75 in.)(0.75 in.) = 1.3125 in. 2, but the area along inclined plane AB is
An=A/cosθ=cos60∘1.3125 in.2=2.6250 in.2The normal stress σn perpendicular to plane AB is
σn=AnN=2.6250 in.29.0 kips=3.4286 ksi=3.43 ksiThe shear stress τnt parallel to plane AB is
τnt=AnV=2.6250 in.215.5885 kips=5.9385 ksi=5.94 ksi