1-90 Section 1 each stress even in symbolic form has the proper units of force per area. The net normal force in this case is σ 1 + σ 2 , and the net shear stress is τ 1 + τ 2 . The state of stress is different at other points in the member. Note that some of the stresses at a point could have different signs, reducing the resultant stress at that location. Such is the case at a point C diametrically opposite to point A in the present example (R, 0, 0), where the axial load F and M y generate normal stresses of opposite signs. This shows the importance of proper modeling and setting up a problem of combined loads before doing the numerical solution. Pressure Vessels Maan H. Jawad and Bela I. Sandor Pressure vessels are made in different shapes and sizes (Figure 1.5.31 and Color Plate 10) and are used in diverse applications. The applications range from air receivers in gasoline stations to nuclear reactors in submarines to heat exchangers in refineries. The required thicknesses for some commonly encountered pressure vessel components depend on the geometry as follows. Cylindrical Shells The force per unit length in the hoop (tangential) direction, N t , required to contain a given pressure p in a cylindrical shell is obtained by taking a free-body diagram (Figure 1.5.32a) of the cross section. Assuming the thickness t to be much smaller than the radius R and summing forces in the vertical direction gives or (1.5.52) FIGURE 1.5.30Illustration of stress analysis for combined axial, shear, bending, and torsion loading. 22NL RLp t = NpR t = . generate normal stresses of opposite signs. This shows the importance of proper modeling and setting up a problem of combined loads before doing the numerical solution. Pressure Vessels Maan H 1-9 0 Section 1 each stress even in symbolic form has the proper units of force per area. The net normal force in this case is σ 1 + σ 2 , and the net shear stress is τ 1 + τ 2 . The state of. solution. Pressure Vessels Maan H. Jawad and Bela I. Sandor Pressure vessels are made in different shapes and sizes (Figure 1.5.31 and Color Plate 10) and are used in diverse applications. The applications