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Determination of the stress-deformed state of contemporary thin-walled structures involving large amounts of computation is carried out by computer using numerical methods, of which those used most extensively are the method of finite elements and the method of superelements [1][2][3]. The main advantage of the method of superelements in comparison with that of finite elements is that the number of unknowns in the algebraic system of resolving equations is reduced through preliminary elimination of the internal generalized displacements of superelements. As a result we obtain an ensemble of superelements which has a considerably smaller number of generalized nodal displacements. The increase in the economy of the calculation algorithm is determined by the decrease in the total number of unknowns in the transformed system of resolving equations and the decrease in tape width.As a result of cooperation between the scientific and production organizations Volgogradneftemash* and Nllkhimmash,t VolglSl, # and VolgSKhl, *W the "Volga" computer system was developed. It is designed to calculate thin-walled structures. The system is based on the methods of finite elements and superelements, using the V. V. Novozhilov's theory of thin shells, for which the assumption of straight normals and the assumption about the absence of stresses in the direction of the normal to the middle surface of a shell are valid. The programs were written in the FORTRAN-IV programming language on an ES computer running the OS operating system. The computerized system was broken into four subsystems depending on types of problems to be solved.The first subsystem is designed to solve the problems of axisymmetric deformation of elastic shell structures with a branching meridian, and the second to solve similar problems but taking into account the work of the material in the elastoplastic region. The third subsystem is designed to determine the stress-deformed state of rotation shells with a nonbranching meridian with allowance for the plastic properties of the material and the change of metrics in the process of deformation, so that large shifts and deformations can be taken into account. This subsystem can be used for evaluating the load-bearing capacity of shells since it enables us during simple active loading to follow the process of growth of deformations and stresses as a function of the level of loading.The fourth subsystem is designed for analysis of the stress-deformed state in the zone of orthogonal joints of cylindrical shells subject to the action of internal pressure and temperature during work of the material in the elastic region.The algorithms of the first three subsystems are based on the method of superelements [2, 4]. Superelements are shells whose meridians are determined by some set of continuous functions. It is assumed that the structure contains up to 55 superelements of different forms connected arbitrarily with each other (directly or through ribs taking account of eccentricities). The cross section of the ribs is a set of...

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