Naumov I. Experimental and numerical estimation of dynamic processes in hardware structural elements under impact and punching

Object of study - the dynamic processes of elastic- plastic deformation and fracture in materials under repeated impacts and punching. The aim of the investigations is the development of experimental and computational methods for study of dynamic processes in thin-walled hardware structural elements at impact loading for evaluating the deformed state and punching conditions. Research Methods are: uniaxial tension of specimens, Vickers hardness tests, tensometry and grid methods, methods of mathematical and computer simulation based on the theories of elasticity, vibrations, dynamic plasticity and fracture, the Method of Finite Differences, Finite Element Method. Theoretical and practical results include: an experimental unit with information - measuring complex for recording the test data of materials and test plates, as well as in theoretically and experimentally justified approach for estimating the deformation and fracture of thin-walled structural elements of machines and devices at impact and punching. Scientific novelty includes: firstly obtained experimental justification of new physical and mechanical laws of dynamic plastic deformation and fracture on impact loading and punching of thin plates and computer hard drives; numerically-experimental approach for determination of the material constants for the dependencies between the strain rate and the number of impacts as well as for dynamic yield stress and strain rate at punching of computer hard drives; the generalized numerical approach for the estimation of deformation and fracture of thin-walled hardware structural elements at repeated impacts and punching based on the Finite Element Method and theory of plasticity had been developed; the influence of velocity of the impactor and the laws of elastic- plastic dynamic deformation in conditions of impact and punching of plates which are the parts of hard disks drives in modern computer systems had been established. Degree of implementation: the obtained numerical and experimental data of the dynamics of elastic- plastic deformation and fracture upon impact and punching of the computer hard disks were used in the design practice in company "Tetra, LTD" ( Kharkiv). Scope: design and refinement of structural elements in aerospace, power plant, automotive and instrumentation industry.