Showing 50 of 813 papers in Mechanics

ON THE CONDITIONS FOR APPLYING EULER’S METHOD TO THE STUDY OF THE STABILITY OF DEFORMATION OF NONLINEARLY ELASTIC BODIES UNDER FINITE SUBCRITICAL DEFORMATIONS

Unknown
1970 SovietRxiv: ru-197001.98404

This paper derives sufficient conditions for using Euler’s static method to study the stability of deformation of isotropic nonlinearly elastic bodies under finite subcritical deformations. Starting from the linearized equations and boundary conditions in Lagrangian coordinates for a body with an ar…

ON THE INFLUENCE OF THE SHAPE OF REGULAR PERTURBATIONS OF THE SURFACE OF A LIQUID JET ON ITS BREAKUP INTO DROPS

B. G. Kholin
1970 SovietRxiv: ru-197001.92225

This paper investigates how the form of regular surface perturbations affects the breakup of low-viscosity liquid jets into drops, with particular attention to suppressing satellite microdrops. Experiments with water and molten ammonium nitrate used pressure pulses from an oscillating membrane to va…

On the Influence of an Admixture of Solid Particles or Droplets on the Structure of a Turbulent Gas Jet

G. N. Abramovich
1970 SovietRxiv: ru-197001.91236

This paper examines how discrete admixtures of solid particles or liquid droplets alter the structure and spreading of a turbulent gas jet. Using Prandtl mixing-length theory and momentum balance for turbulent eddies containing particles, it derives estimates for the reduction of pulsation velocitie…

ON THE DIRECT PROBLEM FOR A LAVAL NOZZLE

Yu. N. D'yakonov, L. V. Pchelkina
1970 SovietRxiv: ru-197001.90316

This paper treats the direct problem of unsteady and steady ideal-gas flow in Laval nozzles of prescribed geometry, including subsonic, transonic, and supersonic regions. The authors formulate the gas-dynamic equations in transformed coordinates and describe a finite-difference marching algorithm wi…

Self-Similar Problem of the Dynamic Theory of Elasticity for a Crack with a Point Source

E. F. Afanas'ev, G. P. Cherepanov
1970 SovietRxiv: ru-197001.88250

This paper studies self-similar dynamic plane-strain elasticity problems for an infinite isotropic body containing a rectilinear crack that begins at a point source and expands at constant subsonic velocity. Using displacement potentials and the Smirnov-Sobolev transformation, the boundary condition…

ON THE NONLINEAR INTERACTION OF RESONATING OSCILLATORS

L. G. Khazin, F. Kh. Tselman
1970 SovietRxiv: ru-197001.84067

This paper studies nonlinear interaction in resonant conservative Hamiltonian systems with multiple degrees of freedom, assuming a single resonance relation among distinct linear frequencies. Using a polynomial canonical transformation, the authors reduce the Hamiltonian to a resonant normal form up…

A REFLECTED ONE-DIMENSIONAL RAREFACTION WAVE IN A CONSTANT GRAVITATIONAL FIELD

K. Dzhusupov, K. P. Stanyukovich
1970 SovietRxiv: ru-197001.83470

This paper studies the one-dimensional reflection of a rarefaction wave from a rigid wall in the products of an instantaneous explosion in a constant gravitational field, for a gas obeying a polytropic equation of state. Starting from the general solution of the gas-dynamic equations for discrete ad…

Passage Through the Self-Oscillation Zone of a Rigid Rotor Rotating in Plain Bearings

A. S. Kel'zon, V. I. Yakovlev
1970 SovietRxiv: ru-197001.82443

The paper examines passage through the self-oscillation zone of a rigid rotor rotating in journal bearings, focusing on the use of elastic supports rather than specially shaped vibration-resistant bearings. A nonlinear model is formulated for a symmetric rotor in elastic journal bearings, and, for a…

THE AVERAGING METHOD FOR NONSINUSOIDAL WAVES

L. A. Ostrovsky, E. N. Pelinovsky
1970 SovietRxiv: ru-197001.78698

The paper develops an asymptotic averaging method for nonsinusoidal waves in arbitrary nonlinear first-order partial differential systems, including cases with slow inhomogeneity, nonstationarity, and possible nonconservative terms. Starting from a family of periodic stationary plane-wave solutions,…

On Steady Capillary–Gravity Waves of Finite Amplitude Caused by a Pressure Periodically Distributed over the Surface of a Flow of Liquid of Infinite Depth

Ya. I. Sekerzh-Zen'kovich
1970 SovietRxiv: ru-197001.78527

This paper studies steady finite-amplitude capillary-gravity waves on an ideal incompressible liquid of infinite depth, forced by a periodic pressure distribution on the free surface. Using conformal mapping, Bernoulli’s condition with surface tension, and Dini relations, the boundary-value problem …

A METHOD FOR SOLVING SOME BOUNDARY-VALUE PROBLEMS IN THE STABILITY THEORY OF CYLINDRICAL SHELLS

L. I. Shkutin
1970 SovietRxiv: ru-197001.77223

This paper develops a method for solving boundary value problems arising in the stability analysis of axisymmetric equilibrium states of circular cylindrical shells. After separation of variables, the problem is reduced to a homogeneous system of ordinary differential equations with exponential coef…

INTEGRAL REPRESENTATIONS OF SOLUTIONS

L. A. Fil'shtinskii
1970 SovietRxiv: ru-197001.67834

The paper derives integral representations for solutions of the differential equations in the technical theory of shallow shells, focusing on the case with constant curvature parameters after transformation to complex variables. The governing coupled shell equations are reduced to a fourth order equ…

ON THE LIMITING DEFLECTION OF A VISCOELASTIC BEAM

É. I. Gol'dengershel'
1970 SovietRxiv: ru-197001.63627

The paper studies the asymptotic deflection of a finite viscoelastic beam of variable cross-section resting on a Winkler elastic foundation, with hereditary material behavior represented by an integral kernel. Using Tauberian theorems of Paley, Wiener, and Gelfand type, it derives conditions under w…

ON THE STABILITY OF FORCED OSCILLATIONS OF A FLUID

V. I. Yudovich
1970 SovietRxiv: ru-197001.62434

The paper studies the stability of time-periodic forced motions of a viscous incompressible fluid in a bounded three-dimensional domain, formulated through perturbations of a periodic Navier-Stokes solution in an energy space. It establishes well-posedness and compact differentiability properties fo…

Determination of the Velocity Profile in the Viscous Sublayer Based on the Principle of Maximum Stability

M. A. Goldshtik, V. A. Sapozhnikov, V. N. Shtern
1970 SovietRxiv: ru-197001.62313

This paper applies the principle of maximum stability to determine the mean velocity profile in the viscous sublayer and buffer region of turbulent channel flow. Using a generalized Van Driest mixing-length formula with adjustable parameters, the authors analyze local hydrodynamic stability of short…

EFFECT OF NONUNIFORMITY OF THE ELASTIC FIELD OF SUPPORTS ON PARAMETRIC OSCILLATIONS OF A RIGID SHAFT

A. S. Kel'zon, K. K. Malinovskii, V. I. Yakovlev
1970 SovietRxiv: ru-197001.61441

This paper examines how nonuniform stiffness in elastic ring supports can induce parametric oscillations in a rigid rotor mounted on one elastic and one hinged support. The authors formulate linear equations for small forced oscillations including gyroscopic effects, viscous damping, rotor unbalance…

ON FINDING POSITIONS OF THE REDUCTION LINK THAT ARE EXTREMAL FOR THE CHARACTERISTIC CRITERION OF THE PERIODIC REGIME OF MOTION OF A MACHINE UNIT

I. I. Artobolevsky, V. S. Loshchinin
1970 SovietRxiv: ru-197001.59268

This paper addresses how to determine positions of a machine unit’s reduction link at which the characteristic criterion of a periodic limiting regime reaches extrema, indicating where inertia forces due to nonuniform initial motion are most significant relative to steady motion. Under standard assu…

SOLUTION OF SPATIAL PROBLEMS OF THE THEORY OF ELASTICITY BY MEANS OF ANALYTIC FUNCTIONS AND CONTOUR INTEGRALS FOR CERTAIN NON-AXISYMMETRIC BODIES

A. Ya. Aleksandrov
1970 SovietRxiv: ru-197001.57871

This paper extends analytic function and contour integral methods for three-dimensional elasticity from bodies of revolution to certain non-axisymmetric bodies whose surfaces can be represented as envelopes of a moving cylindrical surface. The method superposes plane strain and antiplane deformation…

ON THE SPECULAR REFLECTION OF VAPOR MOLECULES AND SUPRAMOLECULAR FLOW IN NARROW CAPILLARIES

B. V. Deryagin, N. N. Fedyakin, A. V. Novikova
1970 SovietRxiv: ru-197001.54882

This paper examines how specular reflection of vapor molecules from capillary walls can alter gas transport in narrow capillaries, producing a flow regime distinct from ordinary Knudsen flow. The authors develop a model in which molecules reflected below a limiting angle have an increased transport …

EQUATIONS OF NONLINEAR ELASTICITY IN DISPLACEMENTS

G. S. Taras'ev
1970 SovietRxiv: ru-197001.50528

This paper formulates equations of nonlinear elasticity in terms of displacements for finite deformations, using Green, Almansi, and Hencky strain tensors together with true and generalized stress tensors. It derives variational relations, stress potentials, boundary conditions, and constitutive law…

DYNAMICS OF A RIGID ROTOR ROTATING IN ROLLING BEARINGS WITH PRELIMINARY AXIAL PRELOAD

A. S. Kel'zon, N. V. Yanvarev
1970 SovietRxiv: ru-197001.48469

This paper analyzes the dynamics of a rigid unbalanced rotor supported by rolling bearings with preliminary axial preload, a configuration used in high-speed precision assemblies to increase stiffness and reduce clearance effects. An analytical relation is derived between axial spring stiffness and …

ON A COMPLETE SYSTEM OF SOLUTIONS IN THE THEORY OF SHALLOW SHELLS

È. I. Grigolyuk, L. A. Fil'shtinskii
1970 SovietRxiv: ru-197001.48397

This paper addresses the difficulty of solving boundary value problems in shallow shell theory caused by the lack of complete systems of solutions for the governing equations. Using integral representations of the general solution, it constructs families of regular solutions expressed through comple…

FINITE PLANE DEFORMATIONS OF AN ELASTIC ISOTROPIC BODY

G. S. Taras'ev
1970 SovietRxiv: ru-197001.46038

The paper formulates finite plane deformation problems for an ideally elastic isotropic body in complex coordinates of the initial configuration, without imposing geometric or physical linearization. It derives geometric compatibility relations in terms of logarithmic strain invariants and rotation,…

THE HYSTERANT OPERATOR

M. A. Krasnosel'skii, B. M. Darinskii, I. V. Emelin, P. P. Zabreiko, E. A. Livshitz, A. V. Pokrovskii
1970 SovietRxiv: ru-197001.38109

This paper introduces the hysterant operator as a mathematical tool for describing hysteresis-type nonlinearities arising in Prager-Ishlinskii models of elastic-plastic behavior. The authors define an elementary hysterant first for continuous piecewise-linear inputs and then extend it to arbitrary c…

INVESTIGATION OF THE PLASTICITY ZONE UNDER AFTEREFFECT FOR CERTAIN BODIES WITH CENTRAL AND AXIAL SYMMETRY

M. I. Rozovskii, N. N. Dolinina
1970 SovietRxiv: ru-197001.34705

This paper studies the time-dependent size of plastic zones in elastic-plastic bodies with aftereffect, focusing on a hollow sphere under internal and external pressure and related axially symmetric cylinder problems. Using operator constitutive relations for shear, volumetric response, and hardenin…

CAMOUFLET EXPLOSION IN LIQUID AND ELASTOPLASTIC MEDIA

L. V. Al'tshuler, A. V. Balabanov, V. A. Batalov, N. A. Gerashchenko, V. A. Rodionov, V. A. Svidinskii, D. M. Tarasov
1970 SovietRxiv: ru-197001.30010

This paper investigates camouflet cavity formation produced by spherical explosive charges in liquids and elastoplastic media, including water, zinc chloride solution, wet clay, aluminum, cement and sand mortar, and rock salt. The authors combine pulsed radiographic measurements of cavity expansion …

ON THE STABILITY OF SELF-OSCILLATIONS OF A FLUID

V. I. Yudovich
1970 SovietRxiv: ru-197001.28271

This paper develops a linearization principle for the stability of periodic self-oscillations in infinite-dimensional dynamical systems, formulated as nonlinear partial semigroups on a Banach space. It proves an analogue of the Andronov-Witt theorem: a smooth cycle is asymptotically stable with asym…

CALCULATION OF THE MAGNITUDE OF STABLE ROUGHNESS AFTER RUNNING-IN (ELASTIC CONTACT)

I. V. KRAGELSKII, V. S. KOMBALOV
1970 SovietRxiv: ru-197001.26436

This paper develops a calculation method for the stable roughness that forms after running-in during sliding elastic contact. Using the molecular-mechanical theory of friction together with a fatigue interpretation of wear, the authors argue that the stable surface state corresponds to the roughness…

SPECTRUM OF A SYSTEM OF MEMBRANE EQUATIONS IN THE CASE OF AXISYMMETRIC VIBRATIONS OF A SHELL OF REVOLUTION

V. B. Lidskii, N. V. Kharkova
1970 SovietRxiv: ru-197001.20260

This paper studies the spectral problem arising from the membrane approximation to axisymmetric vibrations of a shell of revolution with clamped edges, obtained by setting the small thickness parameter to zero in the shell equations. The authors formulate the associated self-adjoint operator, analyz…

On the Laws of Reflection of Body Forces in the Theory of Elasticity Across a Plane Boundary

A. P. Shmakov
1970 SovietRxiv: ru-197001.19231

This paper develops a generalization of Mindlin’s method for elasticity problems in a half-space by using analytic continuation of elastic solutions through a plane boundary. It formulates reflection laws for body forces that allow boundary-value problems with either vanishing displacements or vanis…

APPLICATION OF THE METHOD OF SUCCESSIVE APPROXIMATIONS TO THE INTEGRATION OF BOUNDARY-LAYER EQUATIONS

E. A. Kovach, G. A. Tirskii
1970 SovietRxiv: ru-197001.13618

This paper proposes a variant of the method of successive approximations for numerical integration of two-dimensional incompressible Prandtl boundary-layer equations with an arbitrary pressure gradient, assuming that a solution exists. The method integrates the momentum equation with respect to the …

INVESTIGATION OF STRESSES

A. V. Pogorelov
1970 SovietRxiv: ru-197001.12866

This paper examines stresses arising during axisymmetric buckling of thin spherical shell segments, focusing on an experimental check of a previously derived formula relating stress to shell thickness, local bending geometry, and material properties. Instead of measuring stress directly, the study m…

STABILITY OF CYLINDRICAL SHELLS UNDER THERMAL SHOCK

A. S. VOLMIR, A. T. PONOMAREV
1970 SovietRxiv: ru-197001.08324

This paper develops a mathematical model for dynamic buckling of a finite thin circular cylindrical shell subjected to a localized axisymmetric thermal shock near one end. The formulation couples one-dimensional thermoelastic equations for temperature and axial displacement with geometrically nonlin…

STATICO-GEOMETRIC ANALOGY AND THE METHOD OF COMPLEX TRANSFORMATION IN THE LINEAR THEORY OF ELASTIC SHELLS OF TIMOSHENKO TYPE

B. L. Pelekh, E. I. Lun
1970 SovietRxiv: ru-197001.07342

The paper extends V. V. Novozhilov’s method of complex transformation from the Kirchhoff Love thin shell theory to the linear theory of elastic shells of Timoshenko type, in which transverse shear deformations are included. Starting from the kinematic, equilibrium, constitutive, and compatibility re…

ON STABILITY IN THE THREE-BODY PROBLEM

M. M. Khapaev
1970 SovietRxiv: ru-197001.06939

The paper studies stability in the spatial three-body problem for two planets in canonical variables, with particular attention to the behavior of the slowly varying action variables near resonance lines where integer combinations of mean motions vanish. Using a generalized form of Lyapunov’s second…

ABSOLUTELY CONTINUABLE LIMITING MODES OF MOTION OF MACHINE UNITS WITH PIECEWISE-MONOTONE CHARACTERISTICS

V. S. Loshchinin
1970 SovietRxiv: ru-197001.00742

This paper studies limiting modes of motion for machine units whose reduced force moment depends on the driving angle and kinetic energy and may have piecewise-monotone characteristics with discontinuous slope. Using the kinetic energy equation, it establishes conditions for the existence of inertia…

DYNAMIC PROBLEM FOR A PLANE WITH A CRACK

V. Z. PARTON, B. A. KUDRYAVTSEV
1969 SovietRxiv: ru-196901.97949

This paper analyzes steady-state dynamic vibrations of an infinite elastic plane containing a finite crack subjected to a harmonic normal load on the crack faces. Using elliptic coordinates, the displacement potentials are reduced to Mathieu equations, and the boundary conditions on the crack are tr…