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The bending experienced by a thin elastic electrode insulated on one side is used to obtain “electrocapillary” data on the gold-perchloric acid solution interface. The technique yields self-consistent and numerically reasonable values of the charge on the electrode and the cationic and anionic Gibbs' surfaces excesses. The results are consistent with a specific adsorption of perchlorate ions which is represented by an isotherm of Temkin type. Hydroxonium ions are not specifically adsorbed. The data are limited in number, the numerical value of Young's modulus for the system lacks accuracy : hence the uncertainty of the data is high.

The types of flow occurring in the runner, gate and cavity of a cylindrical bar mould have been investigated and the relation between the flow and local modulus of the moulding determined for crystal polystyrene. The results suggest that non-isothermal shear flow was occurring in the runner while the gate displayed the characteristics of shear flow when heated to the polymer melt temperature and a complex type of flow when cold. The cavity was found, under normal injection rates, to fill by a jetting mechanism which often produced surface irregularities in the product and progressive filling from the gate was only observed at low injection rates. Investigation of local moulding properties revealed that while considerable variations within a specimen existed, these were apparently not due to the mould filling mechanism. They have been attributed tentatively to the small opening of the mould which takes place during injection and to cooling strain.

Poly(m-phenyleneisophthalamide) films were drawn and heat-treated inglycol solution of N, N-dimethylformainide or N, N-dimethylacetamide, and the fine structure and mechanical properties of thus treated films were investigated, comparing them with those treated in aqueous solution.It was found that filmscould be drawn in N, N-dimethylformamide solution at lower temperature and at lower concentration than in aqueous solution. Improvement of orientation, initial modulus and tensile stress at break by drawing or heat-treatment in glycol solution was of similar extent to those in aqueous solution, but the former solution was slightly more effective for improving the elongation at break and crystallinity than the latter.In order to evaluate the degree of crystallinity and orientation, the amorphous X-ray diffraction pattern was determined and the intrinsic birefringence of poly(m-phenyleneisophthal-amide) was estimated; and the finestructure of films was discussed in more detail from the changes in the degree of crystallinity and orientation.

The effect of various levels of cotton and polyester fibers blended during opening and picking on carding efficiency and processing performance was investigated. The cotton was middling grade, 1 1/16-in. staple length, and 4.2 micronaire reading; the polyester was high modulus, 1.5 in. long, and 1.5 denier. As the percent polyester in the blend increased, compression recovery increased moderately and shear friction appreciably. The increase in friction offset the increase in compression recovery so that cylinder load, fiber hooks, and card sliver variability increased with greater polyester content. However, as the polyester content increased, the increase in fiber friction and length uniformity improved drafting efficiency so that second drawing sliver and yarn uniformity improved. Increasing the polyester content of a blend did not improve yarn grade; high cotton content blends had the same grade as high polyester content blends. At constant end breakage, production in spinning increased rapidly to a 65c/35p blend; additional increases in polyster resulted in only slight improvements in spinning efficiency. Very little polyester was lost in the carding waste even with close flat-to-cylinder settings (0.010 in.), which no doubt provided better carding action on the cotton component in the blend than do settings commonly used. However, it is possible that this close a setting for high percentage polyester blends might cause excessive cylinder loading under mill conditions.

We have investigated the elastic properties of several one-dimensional compounds using a vibrating reed technique. A model calculation shows that a vanishing Young's modulus will occur for elastic one-dimensionality. TTF-TCNQ exhibits a small modulus which decreases with increasing temperature extrapolating to zero at T ≈ 500–700K. The uniaxial stress dependence of the metal-insulator transition temperature is calculated to be ¦ d T c / d σ¦ ∼ (10 ± 5) K/bar . KCP shows a much higher modulus and a phase transformation at ∼ 35 K.

Considering soil as an elastic medium, Newmark has presented maximum strains in soil caused by a seismic stress wave. Straight underground structural elements can be designed conservatively using these strains and neglecting the slippage between the element and surrounding soil. It has been shown in this paper that underground elements with bends and branches are subjected to significant bending stresses due to the slippage. A simplified analytical procedure has been presented to account for this effect in the design of underground elements, e.g., piping, electrical cable ducts, and tunnels. The effect of modulus of subgrade reaction and the seismic wave velocity on these stresses is analyzed.

We study the problem of obtaining the bounds on the modulus of one element of a finite unitary matrix once the values of the moduli of a set of other elements are given. The problem is solved in simple cases, and indications of more general cases are given. This question is interesting from a physical point of view since it leads to direct inequalities between sets of partial waves. It would also be useful to extend this kind of results to the continuous matrices where inequalities on cross sections could be obtained.

The axial stress of a fibre, the shear stress at the fibre-matrix interface and the stress in the matrix of short fibre-reinforced materials under tension are calculated using a new model proposed by the present authors. In the present model, the fibre and matrix do not overlap at the region corresponding to the fibre while they have been reported as overlapping in most of the former reports published by other authors. Both single short fibre models and models of regular fibre array are considered. Effects of the aspect ratio of the fibre and the modulus ratio of the fibre and matrix are clarified in the former case and effects of the spacing of fibres in the latter case. The numerical results are found to coincide with the experimental data fairly well.

The Young's modulus, electrical resistivity and thermal expansion coefficient of types I and II carbon fibre/epoxy resin composites were measured at various angles to the nominal fibre lay. The angular dependence of all properties was reasonably consistent with that expected from the application of tensor theory to hexagonal symmetry. The effects of fibre misorientation were examined by considering (1) a network model due to Cook; (2) a Series averaging, and (3) a Parallel averaging model for Young's modulus, and a network model for resistivity. After allowing for fibre contact resistance or imperfect network geometry the network structure gave a satisfactory correlation between modulus and resistivity in terms of the fibre misalignment angle. Earlier data on thermal conductivity also support this model.

Plated wires, 2.5 and 5.0 mils in diameter, have been obtained from various sources and compared to our own 2.5 mil diameter wire made on both copper-beryllium and tungsten substrates. The wires have been tested for their digit, word, and shmoo windows, pulse output and uniformity of output, skew and magnetostriction and their uniformity, the tension and torsion stress changes in the above characteristics, the thickness of the magnetic layer, stability during accelerated aging, and their mechanical characteristics. The characteristics of the wires in the unstressed condition were all adequate for memory application. Differences in signal output and location of the operating windows could be correlated with differences in film thickness and wire diameter. Pulse signal fluctuations were found to be directly proportional to magnetostriction fluctuations. There were great differences observed in the behavior of the samples under stressed conditions. These differences were shown to arise from differences in the local fluctuations in magnetostriction, the modulus and diameter of the substrate, and differences in the metallurgical and magnetic structure of the permalloy film. Accelerated aging showed 2:1 differences in rate between some samples.

The effect of soil modulus, mode of wall movement and base friction conditions, on lateral earth pressure distribution and pattern of failure development in the soil mass is brought out.

The rheological behaviour of doughs prepared from flours treated with potassium bromate, azodicarbonamide and ascorbic acid was studied at large deformations in simple tension. The results were interpreted in terms of isochronal constant strain rate modulus F(t*), and exponent n characterizing the time dependence of modulus F(t). The exponent n can be calculated from the equation: F(t) =F(t*)·(t/t*)n; n= -1 indicates a purely viscous response, n= 0 a purely elastic one. The strengthening effect of the improvers at different moisture absorptions and temperatures was demonstrated by the drifting of the exponent n closer to 0, which indicated that the behaviour of the dough was becoming more similar to that of an elastic body. The stress-strain relation measurements as well as the evaluation of the ultimate properties of the doughs in terms of ‘failure envelopes’ reflected the combined effect of the temperature on both the reaction rate of the improver and the consistency of the dough.

Various theories which have been proposed for the shear modulus of two-phase composites are discussed in relation to their applicability to interstitial composites. The best fit to the experimental data is provided by a theory which considers particle-particle interactions. Non-interacting theories are found to be more suitable for model composites of pre-formed particles in a rubbery matrix. For the interstitial composites this is interpreted as evidence for molecular interactions between the two components in an interfacial layer.

The behavior of an inclusion in a host material subjected to a stress system depends primarily on the ratio of the tangent moduli,E inclusion/E host. An inclusion of suitable material used in the form of a gage will give an identifiable photoelastic-fringe pattern. This pattern is related to the applied biaxial stresses in the diametral plane of the gage, and is independent of the actual modulus and strains in the host material provided that the moduli ratio is more than 300. A program of work has been carried out to verify the use of such an inclusion gage in low-modulus nonlinear viscoelastic materials. The gage geometry used in this work consisted of a hollow cylinder of birefringent material with a ratio of outside diameter to inside diameter of 5 to 1. The host materials were either unfilled or highly filled carboxyl-terminated polybutadiene rubbers. The moduli ratios for both host materials were such that the gages act as rigid inclusions. A theoretical study has also been conducted to find the optimum measuring points within the gage and the fringe patterns created by selected biaxial-stress ratios. The study also showed that the gage sensitivity is virtually independent of Poisson's ratio but depends on the biaxial ratio of the stresses. The values of the sensitivity factor obtained experimentally were close to those derived theoretically. The stressfringe order at the optimum measuring points was obtained by Tardy compensation, and the biaxial-stress ratio determined either from fringe-pattern recognition or by measuring points. Future applications and uses of such a stress-measuring technique will be described.

A study of ultrasonic velocities and internal friction in Bi-Sn alloys was carried out in the concentration range of 0–8·3 atomic percent of tin using the composite oscillator technique, and a set of elastic constants was calculated from the velocity and density data. The elastic constants as well as the internal friction were found to decrease abruptly in the region of solid solution. This peculiar variation is attributed to the semiconducting properties of this alloy system in this concentration range. The temperature variation of Young's modulus was studied for some of the concentrations and Young's modulus was found to decrease linearly with increasing temperature.

The properties and structure of natural cellulosic fibers were investigated by sonic velocify, visible dichroism and x-ray diffraction methods. The following results were obtained: (1) There is a good agreement between the orientation factor determined from the x-ray diffraction method and the visible dichroism of dyestuffs. (2) A linear relation exists between the sonic velocity (C) and the orientation factor from x-ray diffraction (fx); C=8.54fx-0.72(km/sec)for0.6

The elastic properties of copper have been compiled and reviewed. Polycrystalline elastic constants included are: Young's modulus, the shear modulus, the bulk modulus, and Poisson's ratio. Single‐crystal constants of second‐, third‐, and fourth‐order are included. Over 200 references to the experimental literature are given. A few theoretical numbers are included. When sufficient data exist, best values are recommended together with their standard errors. Effects on the elastic constants of temperature, pressure, and mechanical (plastic) deformation are included. The Cauchy (central‐force) relationships and the single‐crystal—polycrystal relationship are also discussed.

The effects of explosive loading on polycrystalline copper have been investigated by measuring the changes in Young's moduli and internal friction of copper specimens immediately after explosive loading and after being subjected to subsequent annealing at different temperatures. The results suggest that although the density of dislocations and other point defects in explosively loaded copper may be higher than for an annealed material, the Young's modulus and internal friction are higher and lower, respectively. The experimental results are explained in the light of Mott's defect modulus theory and the probable nature of dislocation networks in the explosively loaded copper.

A simple mathematical model is proposed for estimating the fore-aft elastic stiffness of pneumatic tires. This model is based upon two idealized solutions, the first being that for the extensional stiffness of a pressurized tube reinforced with inextensible cords, while the second solution is that for the shear deformation of an unpressurized elastic tube. The combination of these two elements allows one to estimate fore-aft stiffness characteristics of pneumatic tires. The validity of the proposed model was tested by static measurements at different inflation pressures of the fore-aft spring rates of four tires varying in size and construction. Additional structural data required for the analytical solution of the model were also obtained from these tires. Comparison of the calculated and experimental results indicates that the trends are generally correct, although close correlation between experiment and calculation is difficult to obtain.

Copper-whiskers with different orientations were excited in flexural vibrational modes. From the resonance frequencies and the cubic compressibility, the elastic constants cik of copper were determined. The results are in good agreement with values obtained by other authors using other methods with macroscopic single crystals of copper. No enhancement of Young's modulus, reported recently in thin metallic films, was seen in Cu-whiskers.

Carbon fibres heat treated to temperatures in the range 1000-2600°C have been irradiated in the spent fuel pond to gamma doses between 1-1000 Megarads (MI). The mechanical properties of the irradiated fibres have been determined by single filament tests. There is a reduction in strength and modulus for fibres irradiated in air, probably due to radiation enhanced oxidation effects. This produces an increase in fibre diameter (≲10%) for fibre originally heat treated to 1000 and 1500°C. This is probably due to fine scale voidage (∼20 A) for which there is some evidence in thin sections prepared from regions close to the surface of these fibres (irradiated to 1000 Mr). The mechanical properties of fibres irradiated to 1000 Mr in argon were unaffected by the irradiation showing that the displacement damage from the irradiation has had little effect on the processes controlling modulus and strength.

Investigations of ultrasonic velocity and absorption are carried out on bismuth-antimony alloys with a concentration of 0-60 at%antimony using the composite oscillator method and the pulse method respectively. The elastic constants are estimated from velocity and density measurements. Anomalous variations of elastic constants and ultrasonic attenuation are observed at a certain critical concentration region, and these are interpreted in terms of changes in lattice parameter and carrier concentration. Studies of the temperature variation of Young's modulus and ultrasonic attenuation are also carried out at some of the concentrations. The observed anomalies in ultrasonic properties confirm the peculiar electronic properties of these alloys in that concentration range.

Results are presented of measurements of the temperature dependence of Young's modulus of Fe-Pt alloys (25-29 at% Pt) both in the ordered and disordered states. Very large anomalies in Young's modulus are observed which are a direct consequence of the Invar properties of these alloys. The largest anomaly has been observed for ordered Fe 3 Pt whose Young's modulus at 77 K is very small, 44×10 10 N / m 2 compared to 15.2 ×10 10 N / m 2 without magnetic ordering.

A theoretical expression has been derived to describe the strain behavior of rigid plastic composites containing spherical filler particles. By combining the predicted ultimate strength values with the appropriate modulus relationship, the complete stress–strain history and corresponding fracture energy may be estimated. The theoretical predictions were compared with experimental values obtained for a general-purpose polyester resin containing spherical glass beads. The influence of silane coupling agents and filler adhesion was also evaluated. Although the experimental values showed considerable scatter, the general trend agreed fairly well with the theoretical predictions.