Ivantyshyn N. Assessing of the inclusions effect on the static and cyclic strength of structurally heterogeneous materials

Object of research - structurally inhomogeneous structural materials - secondary aluminum alloys, cast iron and steel hrafityzovani. Objective: formulation of mathematical models and building design formula to predict the characteristics of static and cyclic strength depending on the shape and volume content of inclusions. Research methods: general relations of elasticity theory, the method of integral Fourier transforms, analytical and numerical methods for solving integral equations, the criteria of fracture mechanics. Formulated computational models of deformation and destruction of local secondary aluminum alloys and cast irons. The approach is based on charts makrozrazkiv tension, simulating intermetalidni inclusion in aluminum alloys and carbon in iron. Constructed singular integral equation corresponding boundary value problems, which reduced the problem of deformation of the material in tension with inclusions. Analytical solutions of integral equations for particles as ellipsoids (spatial task) and ellipses (plane problem). Determined the intensity of external load, causing multiple fracture in materials dispersed phase. Based on the concepts of fracture mechanics obtained formulas to predict the boundary strength, fracture toughness parameter K1S, endurance limits of these materials depending on the volume of content, size and shape of the second phase. The research results are used in metallurgical industry, particularly at the Zaporozhye plant of nonferrous alloys.