Rheological determination of polymer-filler affinity

An experimental method to quantify the affinity of polymers for certain fillers is presented. In this method, the relative viscosity of filled and unfilled polymer systems as determined by capillary rheometry is taken as a measure of the thickness of the adsorbed layer of polymeric material on the filler surface and hence of the affinity of the polymer for the filler. A styrene-butadienestyrene block copolymer is thus found to have a higher affinity for talc than do polypropylene and an ethylene-propylene-diene terpolymer.     

Vibrations and stability of cylindrical panels with elliptical cross section

Summary The free vibrations of cylindrical panels with elliptical cross section subjected to an initial stress state are investigated. The buckling problem of the panel under the stress state considered is studied as special case of the free vibration problem.

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Übersicht Es wird die freie Schwingung offener Zylinderschalen mit elliptischem Querschnitt behandelt, die sich in einem Anfangspannungszustand befinden. Das Schalenbeulproblem wird als Spezialfall der freien Schwingung untersucht.

     

Effects of the interaction between radiation and a disintegrating vitreous material

This article considers the disintegration of a vitreous semitransparent material at the critical point in a stream of radiating gas. A study is made of the effect on the rate of disintegration of the indeterminacy of the effect of interaction between the radiation and the gaseous disintegration products and of the spectral distribution of the density of the radiation flux of the gas with respect to the semitransparancy of the material. An analysis of the error of the gray approximation with calculation of the disintegration of materials with a semitransparency window is also given.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 133–137, September–October, 1978.     

Differentiation along arbitrary orientations

A prevalent problem of mechanics is the differentiation of experimental information with respect to various directions, including the determination of cross derivatives. Simple methods for evaluating such derivatives along straight and curved directions are described. The concepts are demoinstrated at boundary and internal locations of in-plane and transversely loaded plates.     

Propagation of a shear crack in a randomly heterogeneous body

Propagation of a crack in a randomly heterogeneous body exposed to longitudinal shear is considered (in a Born approximation). It is proved that the stress means at the crack tip have singularities on the order of (r)^–1/2. The effective coefficient of stress intensity is introduced. It is known that the propagation of a crack in a homogeneous body is of a local nature, i.e., energy consumption in the growth of the crack is completely determined by the coefficient of stress intensity, which is a local characteristic. The equivalence of the force and energy approaches is mathematically expressed by the Irwin equation [1]. An analog of the Irwin equation is obtained for the case of a randomly heterogeneous body.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 145–148, January–February, 1976.     

A flow pattern map for gas—liquid flow in horizontal pipes

Various flow pattern maps for two-phase gas—liquid flow in horizontal pipes are tested against the 5935 flow pattern observations presently contained in the UC Multiphase Pipe Flow Data Bank.A new flow regime correlation representing an extension of the work done by Govier and Aziz [3] is presented and is shown to be in better agreement with the data than the other correlations tested. A computer program for this correlation is included.It is also shown that there is no significant improvement obtained by including the effects of the physical properties of the fluids using any of the physical property parameters which have been proposed so far.     

Stability of combustion of powder in a phenomenological model with nonadiabatic flame

A stability criterion for combustion of powder is obtained, taking into account the effect of the processes in the gas phase. It is shown that consideration of the effects of a nonadiabatic flame leads to the stability reserve of combustion being reduced and the natural frequency of vibrations being lowered. The effects thus found are physically explained by the radiation of a part of energy from the combustion zone with thermal and acoustic waves.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 6, pp. 82–87, November–December, 1973.Deceased.