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Information × Registration Number 0224U032649, (0124U003747) , R & D reports Title Development of the technology of specified fragmentation of shell structures under dynamic load popup.stage_title Розрахунок напружено-деформованого стану циліндричної оболонки та розроблення експериментальної методики побудови повних рівноважних діаграм за попереднього деформування. Head Ivanytskyi Yaroslav L., Доктор технічних наук Registration Date 28-11-2024 Organization Physico-Mechanical Institute named after GV Karpenko of the National Academy of Sciences of Ukraine popup.description1 Development of the technology for uniform fragmentation of metal shell structures at their dynamic load popup.description2 This study examines the processes of fragmentation in metallic shell structures following their pre-strain and hydrogenation under internal dynamic loading. The aim of the work is to select modes of pre-strain of shell structures and hydrogen saturation of the metal to ensure specified fragmentation under dynamic loading. Research methods – the degree of metal strain will be assessed based on an energy criterion using true equilibrium fracture diagrams. These diagrams will be used to determine the specific fracture energy as an invariant characteristic of the material's resistance to deformation and fracture. For the tubular sample, the stress-strain state and the distribution of strain energy in the cross-section will be calculated, taking into account the effect of hydrogen. The specific fracture energy of the material will be experimentally determined through tensile testing of a cylindrical sample using an optical-digital system to monitor the deformation magnitude in the local volume of the material. After sample fracture, the concentration of absorbed hydrogen will be determined using a LEKO DH-630 gas analyzer, and the total defect magnitude at the fracture will be measured using electron spectrometry. This will allow the determination of the area of brittle fracture depending on the magnitude of pre-strain and the concentration of absorbed hydrogen in the metal. The impact of the magnitude of pre-strain of cylindrical samples on the concentration of gas-phase hydrogen absorbed by the material will be determined for different hydrogenation regimes. The research will identify the conditions under which hydrogenated elastic-plastic material undergoes brittle fracture. Based on the results of the studies, a technology for hydrogen-mechanical treatment of metal products will be developed to ensure the specified fragmentation of shell structures under dynamic loading.  Product Description popup.authors Ivanytskyi Yaroslav L. Hrynenko Mykhailo V. Maksymenko Oleksandr P. Chaban Petro M. Shtaiura Stepan T. popup.nrat_date 2024-11-28 Close