Vasylenko O. Optimum designing of the plate-rod elements on the final state of constructions in conditions of corrosion.

Subject of inquiry is - models, methods and algorithms of design of optimum constructions with accounting simultaneous influence of loadings and corrosive environment. The aim of the thesis is to develop an effective approach to the optimum designing of plate-rod structural elements, which operate under the simultaneous action of power loadings and corrosive environments. There were applied methods of calculation elements of building mechanics constructions, optimum designing and methods of computer modeling of corrosion wear processes. Designed a new general and effective enough approach to solving of problems of optimum designing of constructions, which are operating in conditions of simultaneous influence of loadings and corrosive environments. Proved reliability of the created approach, and carried out the analisys of its effectiveness in comparison with applying straight optimization alghorithms to optimum designing constructions taking into account its corrosion deterioration. The numerical implementation algorithm of the approach was composed, carried out its approbation and usage for solving wide range of weight optimization problems of beans, trusses, frames, rods, thin plates which are operating in conditions of corrosion. There are new data of comparison analisys of results of applying the most well-known models of corrosion wear, which are taking into account influence of stresses on corrosion rate (V.M. Dolinsky, I.G. Ovchinnikov and E.M. Gutman models) for solving problems of optimum designing taking into account corrosion wear were gained. Were built dependances of influence of changing of parameters of math models on characteristics of optimum projects. There were solved real problems of finding of optimum material distribution of plate and rod constructions with fixed operation terms, taking into account requirements of strenghts, stability, rigitiveness and constructive bounds. The results of these solutions point on hight enough effectiveness and reliability of the proposed approach and possibility of generalization this approach onto solving wide range of difficult practically important problems. Implementation extent: the results of thesis have been implemented into calculating practice of enterprises: OJSC "Novomoskovsk Tube Plant", mining/management "Lugantskoye", OHSP "Universal" SE "61 Kommunar Shipbuilding Plant", as well as into science and investigation work of Tehnical Mechanic Institute of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, and in teaching process of Oles' Honchar Dniepropetrovs'k National Universiry in the preparation of students of specialty "Dynamics and Strength." The proposed results can be directly used for the efficient solution of specific problems decreasing weight of constructions operating in corrosive environments.