International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The influence of non-metallic inclusions on the formation of defects in deformed steels and their role in providing crack resistance are considered. It is shown that non-metallic inclusions as stress and strain concentrators are one of the most dangerous sources of defect initiation in steels during pressure treatment. It has been established that the nature of cracks and the features of their growth near nonmetallic inclusions are determined by the type of inclusions, as well as by the scheme of the local stress state, which depends on the loading conditions. An analysis was made of the features of the initiation and development of the cracks near non-metallic inclusions of various types during tensile strain, compressive and bending deformation. It is shown that the most severe way of deformation for the inclusion-matrix system is tensile strain, the softest is compression.

A fracture mechanical behavior of thin-walled elements with through-thickness crack is researched. General analytical methods to determine stress intensity factors (SIF) in such elements are presented. The methods are based on the assessments of nominal stresses in the process of crack growth (first method) and change of inertia moment in defective section (second method). Correction functions are obtained for the central crack under bending for rectangular cross-section of thin-walled beams

The article deals with the influence of the loading rate in the interval from 1 to 1000 mm/min on the mechanical properties of drawing steel sheet, used for the manufacture of automotive parts, under tension and bending conditions. It describes the aspects of material characteristics under tension and bending conditions, while bending tests were made on notched specimens (a modified impact bending test). With an increasing strain rate up to the critical value, the resistance of material against strain increases and hence the yield point and the tensile strength increase, the deformation ability, the deformation homogeneity, the structure and the substructure after deformation, etc. Are changed. The paper presents knowledge that using a modified notch toughness test it is possible to achieve the formability characteristics corresponding to dynamic strain rates even under the static loading

The structural weight reduction is the most visible effect of composite application, but it’s primarily important for aircraft or spacecraft only. In engineering branches the major effect of fiber reinforcement plastics (FRP) application is the ability to solve some fundamental technical challenge, for example: simplifying design of construction, the overall dimensions reducing of the elastic element, non-fragile, etc. In this paper the methodological approach to FRP application considered. Some examples of engineering design for vehicle load-bearing FRP element are presented.

The analysis of two-layer sheet bending moment package under plane strain conditions, taking into account the strain hardening. Approximate analytical dependence for the largest radial compressive stress and the relative displacement of the radius of the neutral surface of the inner layer. The possibility of increasing the permissible degree of deformation and reduce the relative radius of curvature of the inner layer.

The article deals with the influence of the loading rate in the interval from 1 to 1000 mm/min on the mechanical properties of drawing steel sheet, used for the manufacture of automotive parts, under tension and bending conditions. It describes the aspects of material characteristics under tension and bending conditions, while bending tests were made on notched specimens (a modified impact bending test). With an increasing strain rate up to the critical value, the resistance of material against strain increases and hence the yield point and the tensile strength increase, the deformation ability, the deformation homogeneity, the structure and the substructure after deformation, etc. Are changed. The paper presents knowledge that using a modified notch toughness test it is possible to achieve the formability characteristics corresponding to dynamic strain rates even under the static loading.