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In order to predict the mechanical performance of the polyvinyl chloride (PVC) at a high operating temperature,a series of short-term tensile creep tests (onetenth of the physical aging time) of the PV... 相似文献
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K. A. Chapskii 《Mechanics of Composite Materials》1965,1(4):37-41
The author investigates the laws of development of creep strains in bending under conditions of steady creep. Tests run on non-standard specimens for periods of 7500 to 15 000 hr gave values of the basic parameters in the expressions used to describe the creep of the tested plastics. Certain of the creep parameters are shown to depend on the instantaneous modulus of elasticity of the material.Mekhanika Polimerov, Vol. 1, No. 4, pp. 67–75, 1965 相似文献
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N. P. Novikov 《Mechanics of Composite Materials》1973,9(2):204-208
A gasification mechanism is proposed. This mechanism is based on multiphoton photodegradation of the polymer molecules and the resulting formation of free radicals which trigger a chain reaction and the subsequent formation of gas molecules. The kinetics of this process, in which an important part is played by the microstructure of the material, are examined.Institute of Problems of Mechanics, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 2, pp. 232–238, March–April, 1973. 相似文献
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The authors have studied the kinetics of "bleeding" during the heating of oriented and non-oriented plexiglas with accrued operating times of up to 16,000 h. They show that bleeding of the products of degradation of macromolecules from plexiglas is accompanied by a decrease in the volume of the polymer, which causes tensile stresses in the surface layers and may lead to surface cracking."Lenin Komsomol" Riga Red Banner Institute of Civil Aviation Engineers. Translated from Mekhanika Polimerov, No. 2, pp. 346–348, March–April, 1974. 相似文献
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M. A. Shumik 《Mechanics of Composite Materials》1972,8(4):645-648
The dynamical stability of a cylindrical Plexiglas shell exposed to axial compression is studied by means of a nonlinear formulation. Main attention is paid to a study of the waves formed when the stability gets lost. Empirical relationships between the critical load and the geometrical and mechanical parameters of the shell are derived.Moscow. Translated from Mekhanika Polimerov, No. 4, pp. 740–743, July–August, 1972. 相似文献
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Conclusions An analysis of the results of testing hybrid glass organic textolites, containing layers of glass and organic fabric reinforcement in various proportions, along characteristic simple short-time quasi-static loading paths served as a basis for determining a family of strength surfaces for plane stress in the plane of reinforcement. The strength of the five materials investigated is described by a second-order surface equation with allowance for the difference in compressive and tensile strengths. The dependence of the strength surface tensor components entering into the strength equation on the structure parameter representing the relative content of organic and glass fabric in the hybrid textolite is investigated and described. The results obtained can be used in practical calculations for determining the optimum ratio of organic to glass fabric in hybrid material with allowance for the specific requirements to be met by the strength properties of the material when used for structural purposes.Translated from Mekhanika Kompozitnykh Materialov, No. 6, pp. 1021–1026, November–December, 1979. 相似文献
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Conclusions 1. In their deformation properties the polyolefins studied are substances of a single class even under creep conditions. The principal factor which distinguishes the behavior of one polyolefin from another is the critical values of the specific volume Vo. At an identical value of V-Vo (at corresponding temperatures) the creep process is identical in polyolefins of different density.2. Change in the specific volume of polyolefins takes place upon the action, not only of temperature, but also of stress, and also as a result of thermooxidative processes, which exert a strong effect on the creep of these substances.A report presented at the Third All-Union Conference on Polymer Mechanics, Riga, 1976.M. I. Kalinin Leningrad Polytechnic Institute. Translated from Mekhanika Polymerov, No. 1, pp. 22–26, January–February, 1978. 相似文献
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The results of experimental investigations of the creep behavior of blends of poly(vinyl chloride) (PVC) with chlorinated polyethylene (CPE) are presented. Eight types of specimens with the PVC/CPE weight ratios of 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100 are examined. The creep tests were continued for 1000 h. It is discussed how the blend composition affects the elastic and inelastic behavior of the material. The elastic compliance of the blend can be determined from the properties of its components by using the Kerner and Budiansky equations for heterogeneous systems with a phase structure of statistic-dispersion type. The creep compliance (the total current compliance minus the elastic compliance) obeys the power law of creep with coefficients depending on the blend composition. 相似文献
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Statistical analysis of the results of humidity-temperature tests of glass reinforced plastics (GRP)
The effect of moisture and temperature factors on the strength of glass-reinforced plastics (GRP) is examined. In view of the considerable dispersion of the experimental data, a statistical method is used for analyzing the test results. The tensile strength distribution law for KAST-V glass laminate under various humidity and temperature conditions is analyzed.Mekhanika Polimerov, Vol. 1, No. 5, pp. 135–141, 1965 相似文献
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V. I. Andreev 《Mechanics of Composite Materials》1968,4(1):100-103
The author examines the problem of the buckling of a hinger rod of rigid homogeneous polymer material under constant load. The results of an experimental investigation are presented. The theoretical calculations are based on the nonlinear generalized Maxwell equation. A numerical solution has been obtained on a computer. The results of this solution are compared with the experimental data. An analytic solution that makes it possible to estimate certain limiting values is obtained for the linearized equation.Mekhanika Polimerov, Vol. 4, No. 1, pp. 145–150, 1968 相似文献
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A method for determining creep strains of polymer tube specimens (in three mutually perpendicular directions) tested at constant and cyclically changing temperatures is described. The equipment for the programmed variation of specimen temperature and for the application of complex loads is described. The application of the method is illustrated by the results of creep tests on tube specimens of low-density polyethylene (LDP). The creep strain c of thermally cycled specimens is noticeably larger than that of specimens tested isothermally at the median temperature of a given thermal cycle, and in time it becomes larger than the strain of specimens tested isothermally at the maximum cycle temperature.Mekhanika Polimerov, Vol. 3, No. 4, pp. 676–685, 1967 相似文献
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On the basis of an experimental investigation of the creep of SVAM glass-reinforced plastic in different directions it is proposed to calculate orthotropic plates starting from the theory of elasticity of an anisotropic body with allowance for the dependence of the constants on time.Mekhanika Polimerov, Vol. 3, No. 1, pp. 35–40, 1967 相似文献
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A new variant of the theory of creep of plastics with spherical inclusions or pores is proposed on the basis of approximate
equations for the integral parameters and the Volterra principle. Rabotnov's theory of viscoelasticity is used to describe
linear creep of the matrix. The remaining components of the composite are assumed to be elastic. The complete system of operator
equations of the linear viscoelasticity of plastics with spherical inclusions is obtained on the basis of the hypothesis of
elastic deformation of the composite and hydrostatic pressure. Sample calculations are performed.
A. A. Blagonravov Institute of Mechanical Engineering, Russian Academy of Sciences, Moscow. Translated from Mekhanika Kompozitnykh
Materialov, No. 5, pp. 668–675, September–October, 1996. 相似文献