Optimizing conditions of the diamond grinding of siliconized graphite

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 8, pp. 32–34, August, 1988.     

Failure of solid polymers under pulse tension

Results of tests on specimens of polymethyl methacrylate (PMMC) and epoxy resin ÉD-20 MT GFA which were obtained with the help of a dynamic polarization set-up are presented. It is shown that for the entire stage of propagation of the crack from the instant it starts until it stops, the crack length increases spasmodically. Fracture surfaces were fractographically analyzed with a view to establish the interdependence between the spasmodic character of crack growth and the formation and development of microfailures ahead of the crack front. It is observed that occurrence and development of secondary microcracks cannot appear as jumps of the main crack due to the chaotic formation of the microcracks and triviality of their dimensions in comparison with the magnitude of the jumps.Translated from Problemy Prochnosti, No. 7, pp. 14–17, July, 1992.     

Indirect method of estimating the dynamic characteristics of systems utilizing paired transient processes

A proposal is made to estimate the dynamic characteristics of a system by measuring the response of standard and investigated systems to the same dynamic action and subsequently estimating the corrections introducted to the known dynamic characteristics of the standard system. The method is simple to implement and does not require a large expenditure. Translated from Izmritel'yana Tekhnika, No. 9, pp. 6–8, September, 1998.     

Synthesis and Properties of Glasses in the NaF–ZnSO4 System

The glass-forming ability is studied in the NaF–ZnSO₄ system. It is revealed that, when melts are cooled at a rate of 10³ K/s, the glass formation is observed in the concentration range 35–70 mol % ZnSO₄. The characteristic temperatures are determined by differential thermal analysis. According to these temperatures, fluorosulfate glasses can be assigned to low-melting glasses. The density of glasses is measured by hydrostatic weighing. The experimental data obtained are used to calculate the molar volume and the thermal stability parameters of fluorosulfate glasses.     

Pulsed pneumatic transport of solid wastes from reprocessing of spent nuclear power plant fuel to storage

The results of experimental investigations of the effect of a gel-like residue on the transport of pieces of structural materials of fuel assemblies from nuclear power plants by a pulsed pneumatic transport system to storage are presented. The data obtained show that even increasing the viscosity of the wetting medium substantially (by a factor of 100) has little effect on the transport regime and technology. 3 figures, 2 tables, 4 references. Translated from Atomnaya énergiya, Vol. 88, No. 1, pp. 48–51, January, 2000.     

Interrelationship of Poles of Transfer Functions, Models of Output Signals, and Errors of Estimating the Characteristics of Dynamic Systems

An investigation is made of dynamic systems in the range of critical values of the degree of damping. Transfer functions are obtained for oscillatory and aperiodic systems with expressions for the output signals corresponding to them for a (t)-equivalent input signal. Also obtained are comparative estimates of the divergences of the output signals and of the amplitude–frequency and phase–frequency characteristics of the systems.     

Reflection of the accuracy of identification of fuzzy sets in representations of situations

We consider approaches to the analysis of reciprocal relationships (inclusions, equalities) of various situations, represented in an indistinct form. Various functions of data mapping from the subject scale to the universal scale are investigated. The analytical expressions of situations are shown.Translated from Izmeritelnaya Tekhnika, No. 10, pp. 20–23, October, 2004.     

A Model of Quasibrittle Fracture Caused by Pulsed Loading

We study the stress-strain state formed in a plate containing a stationary crack of finite length subjected to pulsed loading, develop a model of quasibrittle fracture caused by loads of this type, and deduce analytic expressions for the stress-strain state near the tip of the stationary crack in the plate. The proposed model admits rigorous physical justification and enables one to describe the development of brittle and quasibrittle fracture processes in materials with cracklike defects under dynamic and static loads within the framework of the same approach. The results of numerical simulation are in good qualitative agreement with the experimentally established regularities of the behavior of the critical parameters of fracture processes.