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The paper presents a brief analysis of the amplitude-frequency characteristics at a variable frequency of vibration excitation in a specimen and constant temperature and at a constant frequency of vibration excitation and variable temperature. The error of determination of the elastic and inelastic characteristics of high-damping materials is estimated by the resonance methods.

We propose a method and an automated installation aimed at the determination of the temperature dependences of the characteristics of elasticity and internal friction of metallic materials. In the course of the tests, the results of measurements of the temperature of the specimen, its resonance frequency, and the amplitude of vibrations at a given temperature are recorded in a computer. The moduli of elasticity and the characteristics of internal friction of the metal are computed at each given temperature by using the proposed relations. By analyzing the results of testing 012Kh18N10T steel, it is shown that the proposed method gives unusual results.

The nondestructive method of determining brittle temperature by analysis of temperature dependences of the elastic modulus and linear thermal expansion is described. The performance of this method is confirmed by tests of a molybdenumndash;carbon alloy in brittle and ductile states as well as of 50S2 and 80S steels in a ductile state at room temperature.

The paper describes a method and setup that provide a better accuracy of the determination of the modulus of elongation and Poisson's ratio at various temperatures in comparison with the widely used methods. As an example, we give experimental data on the temperature dependence of elastic characteristics of D-20 aluminum alloy rods over a temperature range from 77 to 293 K, as obtained by this method.

Literature data and our experimental results obtained in the studies on crack kinetics in three-dimensional polymethyl methacrylate specimens with an inner cavity made in various shapes over a wide range of loading rates are summarized. Crack initiation and steady propagation velocities as well as energy spent for fracture are found to increase nonlinearly, and the delay time of crack initiation decreases with the rate of internal cavity loading.

We report the results of the experimental investigation of the behavior of a rectangular plate in the processes of cutting by linear shaped charges according to the axisymmetric and asymmetric modes of unilateral loading and fracture caused by the explosion of a linear charge. It is shown that the transverse velocities and displacements of the same points of the plate subjected to unilateral explosive cutting by shaped charges are much higher (almost by an order of magnitude) than the corresponding parameters for the other modes of fracture. We also observed that the values of longitudinal mass velocities and displacements in the case of bilateral cutting by shaped charges are 1.5–7.0 times higher than the same parameters for unilateral cutting and explosive fracture without using shaped charges. It is also shown that the longitudinal accelerations attain their maximum values in the case where the shaped charge is placed at a focal distance from the plate.

We describe the methods and present the results of an examination of removable elements of fittings of two power units of the Rovno Nuclear Power Plant after 10 and 13 years of operation. It was discovered that, after the indicated periods of operation, the technical state of these elements was satisfactory and the material of the rods had no serious defects or other types of damage that could restrict the possibility of their subsequent operation. According to the regulations accepted in nuclear power engineering, the operating modes of fittings realized at nuclear power plants are light-duty as far as the number of loading cycles is concerned. Therefore, the degree of local fatigue damage to the metal of the rods does not reach its critical value. The outlined procedure of examination of removable elements of fittings is comprehensive. It is completed by low-cycle fatigue testing of the damaged metal and enables one to perform an adequate analysis of the possibility of subsequent trouble-free operation of the corresponding equipment.

We present the results of an investigation of the influence of low temperatures on the elastic characteristics of iron-glass materials with 3, 5, 12, or 20 wt.% of glass at 77–300 K and show that Young’s modulus exponentially decreases as the glass content of the material increases. We suggest a relation for the evaluation of the Young’s modulus of a composite at various temperatures according to its value at room temperature.

Results are presented from an empirical determination of the time of formation of the prefracture zone at the tip of a preexisting crack in the dynamic fracture of polymethylmethacrylate and certain geological materials. An analogy is found between this zone and the life of the material after crack formation within the framework of the kinetic theory of the strength of solids.

The method of index grids yielded experimental data on the distribution of residual deformations in a plate made of alloy AMg6 after it had been pierced by an elongated wedge-shaped punch with a speed of approximately 4000 m/sec. The article analyzes the possibility of weakening barriers of natural and artificial geomaterials where the distribution of residual stresses is similar.

Results are presented from an experimental study of the fracture of bulk specimens of polymethylmethacrylate during the explosion of an acetylene-air mixture in a cylindrical cavity with disk-shaped and radial cracks about its circumference. It is shown that the character of fracture depends not only on the rate of loading of the walls of the cavity and the form of the initial crack, but also on the interval of load application. Crack velocity under experimental conditions is intermediate between the velocity of slow cracks associated with quasistatic hydraulic rupture and the velocity of fast cracks formed in impulsive fracture. The duration of action of the critical level of stresses during fracture is discussed. Critical fracture surfaces are constructed in the space of the loading parameters for the criterion of the maximum stress-intensity factor for disk-shaped and radial cracks.

The results are presented of investigations of the effect of various force factors on the level of longitudinal and transverse displacements in explosion cumulative cutting a right-angled plate. Comparison on the calculated and experimental data indicate that they are in satisfactory agreement. The results show that the level of transverse displacements is controlled by the cumulative and gas-dynamic effect of the charge whereas the level of the longitudinal mass velocity and displacements is controlled by the cumulative effect.

The article investigates the structural strength of the metastable austenitic steel 03Kh16N9M2 and of the steel of the transition class (martensite + residual austenite) 05Kh14N5DM in the temperature range from 293 to 77°K for the purpose of determining their suitability for large components in cryogenics. It is shown that for their characteristics of impact toughness and low-cycle fatigue steel 05Kh 14N5DM containing up to 15% residual austenite cannot be recommended as material of cryogenic structures operating at 77°K.

Data on the temperature dependence of the moduli of longitudinal elasticity E of a number of commercial steels of the ferritic, martensitic, austenitic, and transition classes in the temperature interval from room temperature to the temperature of liquid helium are presented. It is shown that for the austenitic and transition classes of steels, the elastic modulus E does not increase, but decreases when the test temperature is lowered within certain temperature ranges. It is suggested that this anomaly is associated with antiferromagnetic ordering in the austenite.

The article describes a device for study of the elasticity characteristics and coefficient of internal friction of materials in vacuum at low temperatures up to 10 K. As an illustration, temperature dependences of the Young's modulus and logarithmic decrement of vibrations of steel 01Kh12G9N3 with anomaly of the Young's modulus are presented.