Thermoelastic stresses in a nonuniform orthotropic cylinder

The stress distribution in a cylinder with cooling nonuniform with respect to the circumferential coordinate is investigated. The nonuniformity of the mechanical properties of the material in this direction is taken into account. Numerical results obtained at values of the parameters characteristic of wound glass-reinforced products are discussed.Moscow Power Engineering Institute. Translated from Mekhanika Polimerov, No. 3, pp. 560–563, May–June, 1975.     

Mechanism of occurrence of microcirculatory phenomena in a constant magnetic field

A motion-picture study of the capillary network of the interdigital membranes of frogs has been carried out in order to clarify a number of effects observed after individual parts of the body and the whole organism are placed in a constant magnetic field. A constant magnetic field is observed to have three principal effects on the blood flow. The intensified blood flow following exposure to the field is explained as a complex reflex response mechanism, in which a definite part is played by a change in blood particle potentials and by processes of aggregation with subsequent disaggregation.Paper presented at the First All-Union Conference on Engineering and Medical Biomechanics on the topic: Problems of Microcirculation and Mass Transfer, Riga, October, 1975.Riga Scientific-Research Institute of Traumatology and Orthopedics. Translated from Mekhanika Polimerov, No. 5, pp. 891–894, September–October, 1975.     

Mathematical model of muscular contraction with a ccount of excitability

A model of muscular contraetion has been developed which establishes the relationship between normal stresses and longitudinal deformations of the muscle tissue and takes into account its excitability. A transfer function has been proposed for the equation describing the behavior of the muscle as a dynamic system which is controlled by synegisms. The validity of the model has been tested experimentally. The model has been used to develop type-II Lagrange equations for the solution of the basic task of biomechanics for some movements of the human body.Paper presented at the FirstAll-Union Conference on Engineering and Medical Biomechanics, Riga, October, 1975.P. F. Lesgaft State Institute of Physical Culture, Leningrad. Translated from Mekhanika Polimerov, No. 4, pp. 608–612, July–August, 1975.     

Forced axisymmetric oscillations of a viscoelastic cylindrical shell

The variational problem of forced oscillations of a cylindrical shell is reduced to a system of linear integrodifferential equations for which a periodic solution is constructed.Moscow Institute of Electronic Machinery. Translated from Mekhanika Polimerov, No. 6, pp. 1111–1114, November–December, 1975.     

Certain problems in developing a theory and design methods for anisotropic shells and plates with finite stiffness in shear. A survey

A survey is presented here of research on theory and design methods for shells and plates made of anisotropic materials, such as laminate reinforced plastics [4–13], compliant in shear. The report is based mainly on studies made at the Western Science Center, Academy of Sciences of the Ukrainian SSR during the last five years (after the previous survey [8] has been published), with the introduction of generalized Timoshenko-type theories.Branch of Mathematical Physics, Institute of Mathematics, Academy of Sciences of the Ukrainian SSR, L'vov. Translated from Mekhanika Polimerov, No. 2, pp. 269–284, March–April, 1975.     

Particular case of the deformation of a nine-atom model

The dependence of the tensile loading on the length of a nine-atom plane model is calculated. The shapes of the model in tension are determined.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 3, pp. 545–547, May–June, 1975.     

Optimization of a cylindrical composite shell with a viscoelastic core in axial compression

The problem of the optimal design of a composite shell in creep is formulated. The progressive buckling of a cross-wound reinforced cylindrical shell supported on a viscoelastic core is considered as a particular case. The reinforcement structure and shell thickness corresponding to minimum weight for a given load and service life are found.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 3, pp. 442–446, May–June, 1975.     

Fatigue strength of glass-reinforced plastics (GRP) in shear in the plane of reinforcement

The results of an investigation of the fatigue strength of three grades of glass-reinforced plastic are described. It is shown that cyclic loading with gradually increasing stress amplitude can be used to determine the fatigue strength at a given ambient temperature and loading frequency.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 5, pp. 928–931, September–October, 1975.     

Effect of shear compliance in bending and torsion on the stress concentration in a transversely isotropic plate with a hole whose edge is supported

The stress concentration in shear-compliant, transversely isotropic plates with a hole whose edge is supported has been investigated in bending and torsion. Two variants of the boundary conditions are examined. It is shown that the use of the classical Kirchhoff model may lead to a number of qualitative discrepancies.Mathematical Physics Branch, Institute of Mathematics, Academy of Sciences of the Ukrainian SSR. Translated from Mekhanika Polimerov, No. 3, pp. 458–463, May–June, 1975.     

Determination of the elastic and damping properties of the human femur in bending

The results of an experimental investigation of the deflection of the human femur subjected to a bending moment are presented. The existence of two principal bending planes is established. The equivalent flexural rigidity of the dry bone is calculated for both static and dynamic loading. It is found that the human femur has a nonlinear elastic characteristic. The stiffness and damping properties obtained in static and dynamic testing are compared.Paper presented at the First All-Union Conference on Engineering and Medical Biomechanics, Riga, October, 1975.Moscow. Translated from Mekhanika Polimerov, No. 4, pp. 642–646, July–August, 1975.     

Effect of compression on bone tissue crystals

The effect of compressive forces on the mineral components of bone tissue was studied. On the basis of x-ray diffraction analysis and the observed electrical and recrystallization effects, it is proposed that compression has a direct effect on the formation of callus through a definite means of compression osteosynthesis.Paper presented at the First All-Union Conference on Engineering and Medical Biomechanics, Riga, October, 1975.Orthopedic Clinic, Semmelweis Medical School, Budapest, Hungary. Translated from Mekhanika Polimerov, No. 4, pp. 664–668, July–August, 1975.     

Micromechanical investigation of osteons with crossed lamellae

A micromechanical investigation of osteons with crossed lamellae has shown that they can be regarded as orthogonally reinforced material. The stress-strain curve has a break at low stresses. This effect can be explained by reference to the mechanical behavior of orthogonally reinforced laminates. It is assumed that a stress concentration develops at the fiber-matrix interface in the lamellae with transverse fibers oriented at 90° to the direction of loading, and that microfractures can develop in the osteon before the proportionality limit of the fibers parallel to the loading axis is reached.Study No. 73.00430.04 of the Italian National Research Council. Paper presented at the First All-Union Conference on Engineering and Medical Biomechanics, Riga, October, 1975.Rome University. Translated from Mekhanika Polimerov, No. 4, pp. 669–673, July–August, 1975.     

Rate of resorption of polymeric implants in relation to biological fluid hydrodynamics

The dissociation of water-insoluble macromolecular complexes dissociating with the formation of soluble macromolecules is theoretically examined. The dissociation dynamics in static and open systems are compared (model media and the living organism, respectively). The effect of the rate of metabolic processes and the water-salt balance on the dissociation-association equilibrium in the organism is predicted. The effect of the tension in thread formed from a polycomplex on its life is analyzed for constant and relaxing stress. The use of the theory for predicting the resorption times of polymeric implants (sutures) in the living organism is demonstrated.Paper presented at the First All-Union Conference on Engineering and Medical Biomechanics, Riga, October, 1975.All-Union Scientific-Research Institute of Medical Polymers, Moscow. Translated from Mekhanika Polimerov, No. 4, pp. 740–743, July–August, 1975.     

Connection between the mechanical characteristics of the human abdominal aorta and its biochemical composition

The basic characteristics of the mechanical properties of the subrenal portion of the abdominal aorta have been determined experimentally for biaxial stretching, and their change with increase in size has been established. Amounts of the five main biochemical components of the aorta wall have been determined and a correlational analysis between the mechanical characteristics and biochemical composition has been carried out.Paper presented at the First All-Union Conference on Engineering and Medical Biomechanics, Riga, October, 1975.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Riga Scientific-Research Institute of Traumatology and Orthopedics. Translated from Mekhanika Polimerov, No. 4, pp. 722–729, July–August, 1975.     

Mechanical properties of a carbon-fiber-reinforced plastic and the residual stresses in wound components made out of combined composites

A technique for calculating the residual stresses in wound components made out of mixed carbon-fiber-and glass-fiber-reinforced plastics and the results of the calculations are presented. The effect of the conditions under which the components are wound on the magnitude and nature of the residual stresses distribution in components made out of combined composites is investigated. The results of the calculations are compared with the experimental values.Translated from Mekhanika Polimerov, No. 6, pp. 996–1004, November–December, 1975.     

Comparative performance of living and dead bony tissue under static and dynamic loading

The dependence of the mechanical properties of bony tissue on different conditions of storing the samples has been studied. As the performance characteristic under static loading we used the ultimate compressive strength of the bony tissue, and under dynamic loading we used the specific impact strength.Paper presented at the First All-Union Conference on Engineering and Medical Biomechanics, Riga, October, 1975.I. M. Sechenov First Moscow Medical Institute. Translated from Mekhanika Polimerov, No. 4, pp. 647–649, July–August, 1975.     

Minimal Submanifolds in a Locally Symmetric and Conformally Flat Space

We study minimal submanifolds in the locally symmetric and conformally flat Riemannian manifold and generalize Yau's result obtained in J. Amer. Math. 97 (1975), 76–100.     

Progressive increase in the displacements of a glass-reinforced plastic helicopter blade under the influence of its own weight

The question of the progressive increase in the displacements of a glass-reinforced plastic helicopter blade under its own weight is examined. Integral operators, expressed in terms of fractional-exponential functions, are used for solving the flexural creep problem. The creep curve parameters for simple deformation (tension and torsion) are found for ÉF-32-301 glass-reinforced textolite.K. É. Tsiolkovskii Moscow Aviation Engineering Institute. Translated from Mekhanika Polimerov, No. 5, pp. 943–946, September–October, 1975.     

Equilibrium glass-plastic pressure vessels of minimum mass with a nongeodesic winding

A lens-shaped vessel having various central apertures made by a continuous winding process is considered. Using the methods of variational calculus, the optimum winding trajectory (yielding a structure of minimum mass) is established, subject to certain limitations regarding the angle of geodesic deviation and the stress level in the filaments. The shape of the base is determined with due allowance for the trajectory found in this way, which comprises sections of geodesic lines and lines of limiting deviation.Translated from Mekhanika Polimerov, No. 6, pp. 983–987, November–December, 1975.     

Investigation of the asymptotic behavior of Green's function for the waveguide problem of propagation near the surface of a conducting sphere

The field of a point source in the waveguide at a point slightly above the waveguide is investigated.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 51, pp. 138–154, 1975.In conclusion, the author expresses his gratitude to his scientific advisor V. S. Buldyrev.