Sheychenko R. Strength assurance of thin-walled structures with increased technical characteristics

The thesis deals with the improvement of methods and models providing of thin-walled mechanical engineering designs with strength under the action of operational loadings. The reasoning for rational parameters and design solutions for thin-walled engineering structures is carried out according to the criteria of mass minimization, stresses reduction, and service life increasing. Various additional criteria such as cost, manufacturability, economy, energy efficiency, can be taken into account in the formation of the quality function. The dependences approximations of criterion values, which are gradually localized, from variable parameters are taken into account. The structure, design and technological solutions of thin-walled engineering structures, structural parameters and operating modes are set as generalized parameters. The following generalizations are considered: unification, expediency, efficiency, loading identification, verification, forecasting, a tune-up in the development of the known approach. The algorithmization of proposed methods for calculating of the stress-strain state of thin-walled engineering structures has also been carried out based on a combination of the advantages of universal and special systems. A number of applied problems are solved. Parametric finite element models of researched objects have been developed based on a set of studies of the deformed state of the main design's elements. The rational design parameters of innovative thin-walled engineering structures have been determined. The results of experimental studies of innovative tank carriage, platform carriage and loading cranes, which are designed and manufactured based on the implementation of recommendations from the current research, are presented. A qualitative comparative analysis of experimental and computational studies of the structures deformed state were carried out. They are combined with certification tests, during which the stresses in the main designs elements were recorded. The operational loadings are determined which are acting on thin-walled structures. During the tests, regularities were established that determine the dependence of the components of the loading on the structure from various factors. Verification of the numerical model's parameters of thin-walled engineering constructions elements was carried out. Designed on the basis of researches innovative structures have improved technical and economic characteristics compared with similar ones.