824Flaws in a material and complexities in a structure lead to nonuniformities in their structural, stressedstrained, and strength states, uncertainty in their behavior, and the necessity of increasing their strength margin. The latter is not always possible. Let us consider the influence of the strength nonuniformity (SU) on a destruction process, acoustic emission (AE), the strength of a material, and the accuracy of its non destructive testing (NDT).The ranges in the values of the dimensions of an object or the coordinates of its structural elements, their deformation energies or fracture intensities, the values of the characteristics of the acting or maximum tolerable stresses, strains, etc., may serve as the criteria for the type of strength state nonuniformity and its indices. In these cases, we deal with structural, energy, kinetic, strength, or strain nonuniformities [1].The strength nonuniformity (SN) of structural elements of a material prevents an object from complete destruction, which is localized at the stage of crack formation and growth at the moment when the critical concentration of microcracks is reached within a limited volume of a material, whose dimensions deter mine the cluster size or the major crack jump size. A material's SN is a prerequisite of the kinetic nonuni formity of crack formation, which manifests itself as comparative strengthening and a decrease in the frac ture intensity, whose termination moment is determined by the most durable among the damaged struc tural elements. The SN of a group of specimens leads to an uncertainty of their functional properties, the necessity of increasing their strength margin, or individualization in applying NDT methods.The NDT of the strength of materials and structures is based on the nondestructive estimate of the rep resentative strength indices, which allows forecasting of the instant that destruction will occur. Therefore, the criterion for the kind of the strength state and the SN of a particular specimen or the SN of a group of specimens will be considered to mean, respectively, the time and the range of times before the fracturing of structural elements of the corresponding test object or specimens of this group.The time until the fracture of a structural element is described by the Zhurkov formulawhere τ 0 has a value of the order of the period of atomic oscillations, U 0 is the activation energy of the destruction process, ω = γσ(t)/KT is the parameter structural element strength state, γ is the structure sensitive coefficient, σ(t) is the tensile stress, t is the current time, K is the Boltzmann constant, and T is the absolute temperature.Abstract-Nondestructive testing of the strength of materials and structures is based on the evaluation of representative strength indices that allow forecasting of the instant that destruction will occur. Flaws in a material and complexities in a structure lead to nonuniformities in their structural, stressedstrained, and strength states, to the reduction of the testability of objects, and the necess...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.