The next step was entering Young's modulus and Poisson's ratio for the type of steel used. Then, dimensions were entered including the radius, height and thickness of the cylindrical shell portion, the thickness and height of the top section, and the thickness of the base. The structure was loaded by entering zero pressure at the surface of the fluid in the vessel and linear hydrostatic pressure at the base. Having specified all required inputs, the program then performed the analysis and calculated the deflections, forces and stresses. The total time required for the calculations was less than 3 minutes.
Computerized handbooks offer tremendous versatility.
For example, in the pressure vessel example the ability to quickly model flat, spherical, conical and ellipsoidal top and bottom configurations is provided. Thus, parametric studies are at the engineer's fingertips. Of course, there are some limitations to the computerized handbook approach. The stress values generated by the handbook are theoretically just as accurate as the finite element analysis because the same formulations are used. However, limitations arise from small geometric details which cannot be modeled with the handbook, such as the welding and reinforcements at the base of the shell where the base intersects the cylinder.