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Information × Registration Number 0225U004324, (0124U003747) , R & D reports Title Development of the technology of specified fragmentation of shell structures under dynamic load popup.stage_title Розроблення експериментально-розрахункової методики проведення натурних випробувань для встановлення оптимального попереднього-пружно-пластичного деформування та умов наводнювання масштабної моделі. Head Ivanytskyi Yaroslav L., Доктор технічних наук Registration Date 01-12-2025 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 During the implementation of the project, a comprehensive set of theoretical, experimental, and numerical studies was carried out, aimed at developing a new method for homogeneous fragmentation of metallic shell structures under dynamic loading. A fundamentally new approach was proposed, based on combining controlled pre-strain with subsequent saturation of the metal with gaseous hydrogen at a specified concentration. This combination makes it possible to significantly reduce the specific fracture energy and to ensure the formation of fragments of predetermined sizes without introducing mechanical stress concentrators. In the course of the work, the methodology for measuring local deformations using an optical-digital measurement system was improved, and the relationship between internal damage accumulation and equivalent strain was established. Numerical modeling of the stress–strain state using the finite element method was performed, taking into account the influence of hydrogen. Based on complete fracture diagrams, the specific fracture energy of the metal was determined as an invariant characteristic of resistance to deformation, and the degree of energy-based damage was evaluated depending on prior deformation and absorbed hydrogen concentration. New data were obtained on the regularities of reducing the specific fracture energy of steel by a factor of 5–7, depending on the degree of pre-strain and hydrogen concentration. Fractographic and spectrometric analyses confirmed the formation of a defective structure within the metal volume, which promotes brittle fracture. Full-scale tests of scaled models at the proving grounds of the Army Academy and the State Enterprise “Yuzhnoye Design Office named after M.K. Yangel” confirmed the effectiveness of the developed method. The obtained results are of fundamental importance for the physics of metal fracture and of practical importance for the development of munitions with predictable fragmentation characteristics... Product Description popup.authors Stepan T. Shtaiura Petro M. Chaban Mykhailo V. Hrynenko Yaroslav L. Ivanytskyi Oleksandr P. Maksymenko popup.nrat_date 2025-12-01 Close