Viscosity Of Solids Research Articles

The role of viscosity of solids in microparticle cratering

The importance of viscous effects on the impact cratering process has been investigated. The shock wave front region was characterized by the balance of inertia and viscous forces (Reynolds number ⋍ 1), and by a continuous distribution of all thermodynamic quantities. The width of the shock wave front region and its flow properties were then related to the impact particle size and velocity, and to the target material properties. Experimental data for aluminum demonstrated that cratering characteristics were changed when the impact particle size was the same order of magnitude as the shock wave front region. An analytical model was developed for cratering dominated by this “viscous” flow. Results from this model indicate a substantial decrease in crater radius and increase in crater surface temperature when compared with inviscid analysis. In addition, a new test method was identified to evaluate the viscosity of solids.

An apparatus for measuring the dynamic shear elasticity and viscosity of solids at high audio frequencies

An apparatus has been designed to measure the dynamic properties of organic glasses at high audio frequencies. The principle of the method employed was that the material, in the form of a rod, was used as the suspension of a moving coil galvanometer. Freely decaying torsional oscillations were detected and displayed as a repeating trace on a cathode-ray oscilloscope. This enabled the logarithmic decrement and frequency of the oscillations to be measured directly. Some typical results are presented.

Measurements of Mechanical Properties of Polyisobutylene at Audiofrequencies by a Twin Transducer

Apparatus has been developed for measuring the dynamic viscosity and rigidity of soft rubber-like solids in small oscillating deformations. A plate rigidly attached between two identical coils in two permanent magnets shears a pair of disk-shaped samples when a driving current is passed through one coil. The open circuit voltage from the other coil is compared in amplitude and phase with the driving current by a method in which all measurements are in the form of settings of a potential divider. The apparatus has two advantages over the more familiar resonance devices: (a) the amplitudes of motion, which need not be measured directly, are extremely small, thus minimizing any non-linear effects, or temperature change due to heat dissipation; (b) a continuous range of frequencies, spaced as closely as desired, is available without adjusting masses. The dynamic rigidity and viscosity of two samples of polyisobutylene, of molecular weights 1.2 and 0.47 million, have been measured at 15, 25, and 35°C at frequencies from 20 to 600 cycles/ sec., with a reproducibility of five percent or better. The rigidity increases and the viscosity decreases with increasing frequency. Both decrease with increasing temperature, and are almost independent of molecular weight. The temperature dependence is quantitatively explained by the assumption that stresses relax by flow processes whose apparent activation energies are all identical with that characterizing the steady flow viscosity.

Molecular Interaction in Monolayers: Viscosity of Two-Dimensional Liquids and Plastic Solids. V. Long Chain Fatty Acids

Molecular Interaction in Monolayers: Viscosity of Two-Dimensional Liquids and Plastic Solids. V. Long Chain Fatty Acids

Some Methods for Studying the Viscosity of Solids

Some Methods for Studying the Viscosity of Solids

Maxwell's theory of the viscosity of solids and certain features of its physical verification

Maxwell's theory of the viscosity of solids and certain features of its physical verification

XX. Maxwell's theory of the viscosity of solids and its physical verification

(1888). XX. Maxwell's theory of the viscosity of solids and its physical verification. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 26, No. 159, pp. 183-217.

The Bakerian Lecture: On the viscosity or internal friction of air and other gases

All bodies which are capable of having their form indefinitely altered, and which resist the change of form with a force depending on the rate of deformation, may be called Viscous Bodies. Taking tar or treacle as an instance in which both the change of form and the resistance opposed to it are easily observed, we may pass in one direction through the series of soft solids up to the materials commonly supposed to be most unyielding, such as glass and steel, and in the other direction through the series of liquids of various degrees of mobility id the gases, of which oxygen is the most viscous, and hydrogen the least. The viscosity of elastic solids has been investigated by M. F. Kohlrausch and Professor W. Thomson; that of gases by Professor Stokes, M. O. E. Meyer, and Mr. Graham.