The Variation-Difference Method of Design of Shells with Normal Unconjugated Coordinate System and Design of Some Type of Surfaces for Checking of the Correction of the Program

At the classical literature of the design of the shell there is used the coordinated system of the middle surfaces of principle curvatures or common non-orthogonal coordinate system. The system of equations of the shells of complex forms is complicated and it’s difficult to receive the analytical decision. For analyses of the shells with non-orthogonal coordinate system and the most shells of complex form in the coordinate system of principle curvatures there is used usually finite element method which usually uses only the equation of the surface but don’t take into account the geometrical characteristics of the middle surfaces of the shell. At the chair of strength of materials and constructions of Engineering Academy RUDN there is worked up the complex program VRMSHELL for analyses of the shells of complex forms by variation-difference method. The complex includes the library of curves on the base of which there are calculated the geometrical characteristics of the classes of the surfaces included at the program complex. The complex includes the classes of surfaces as cylindrical, surfaces of rotation, Joachimsthal’s surfaces, Monge’s surfaces. The coordinate system of surfaces of these classes is the coordinate system of principle curvatures.