Showing papers on "Young's modulus published in 1969"
TL;DR: In this article, the relationship between the ash content of rabbits' metatarsals and their modulus of elasticity, static strength, work-to-failure and impact strength was determined.
445 citations
TL;DR: In this article, a method for increasing this damping by cutting the constraining layer into appropriate lengths is discussed, based on effective complex elastic moduli of an equivalent homogeneous medium.
Abstract: Viscoelastic materials are used extensively to damp flexural vibrations of metallic structures; it has been known for some time that the energy dissipation due to shear strain in the viscoelastic layer can be increased by constraining it with a stiffer covering layer. In this paper, we will discuss a method for increasing this damping by cutting the constraining layer into appropriate lengths. The analysis for a single layer of this treatment is relatively straightforward. The damping can be increased still further by using several layers; in this case, the analysis is based upon effective complex elastic moduli of an equivalent homogeneous medium. One result found from this analysis is that, if the element length of the constraining layer is optimum, the damping depends primarily upon the stiffness of the constraining layer and the loss coefficient of the viscoelastic material, and only indirectly on the shear modulus of the viscoelastic layer. Experimental data is presented for comparison with the theoretical predictions.
161 citations
TL;DR: In this paper, the variation of the longitudinal Young's modulus with mean cellulose microfibril angle of the wood substance of the earlywood of a softwood has been determined from small clear samples.
Abstract: The variation of the longitudinal Young's modulus with mean cellulose microfibril angle of the wood substance of the earlywood of a softwood has been determined from small clear samples. The longitudinal Young's modulus falls steeply as the angle between the longitudinal axis and the mean microfibril direction in the cell walls increases. The variation has been explained in both form and magnitude by applying the elastic theory of a fibre composite material with distributed fibre directions to a model of the experimental material. It confirms the two phase concepts of the plant cell wall, as far as the elastic properties are concerned, of rigid crystalline microfibrils embedded in an isotropic matrix of amorphous and paracrystalline materials.
157 citations
TL;DR: In this paper, the authors present the results of a series of experiments on COHESIVE SOIL and DRY SANDS and show the effect of different levels of stress on the performance of different types of clays.
Abstract: THE WRITERS ARE GRATEFUL TO WHITMAN, HOLT AND MURPHY, AND DOBRY AND POBLETE FOR DEMONSTRATING THE GOOD AGREEMENT BETWEEN VALUES OF THE SHEAR MODULUS CALCULATED IN THE PRESENTED EQUATION AND SHEAR WAVE VELOCITIES MEASURED IN THE FIELD BY GEOPHYSICAL METHODS AT TWO DIFFERENT SITES. TEST RESULTS SHOW THE EFFECT OF VOID RATIO, AMBIENT STRESS, STRESS HISTORY, FREQUENCY, AND STRAIN AMPLITUDE ON THE VIBRATION SHEAR MODULUS OF THESE UNDISTURBED SAMPLES. INDEX PROPERTIES IN THE CLASSIFICATION OF VARIOUS UNDISTURBED COHESIVE SOILS TESTED ARE PRESENTED IN A TABLE AND THEIR PARTICLE SIZE DISTRIBUTIONS SHOWN IN A FIGURE. THE VALUES OF VOID RATIO ARE PRESENTED IN A FIGURE. ANOTHER FIGURE PRESENTS THE EFFECT OF ISOTROPIC COMPONENTS OF STRESS ON UNDISTURBED SAMPLES. THE EFFECT OF OVERCONSOLIDATION RELATIONSHIPS ARE PRESENTED. WHITMAN, HOLT AND MURPHY HAVE PRESENTED A FIGURE SHOWING A CURVE BY WHICH THE MODULUS FOR HIGHER STRAIN AMPLITUDES MAY BE COMPUTED FROM THE MODULUS AT SMALL STRAIN AMPLITUDES. RESULTS ARE PRESENTED IN A FIGURE OF (1) COHESIVE SOIL AND (2) DRY SANDS WHICH WERE TESTED AT DIFFERENT FREQUENCIES AND NUMBERS OF CYCLES. DATA FOR BOTH HOLLOW AND SOLID CYLINDRICAL SPECIMENS SHOWED THE EFFECT OF THE VARIATION OF STRAIN WITHIN THE SPECIMEN TO BE SMALL. THIS IS ALSO TRUE FOR LARGE STRAIN AMPLITUDES PROVIDED THE MEASURED PARAMETERS ARE CORRELATED TO THE AVERAGE SHEAR STRAIN AMPLITUDE IN THE SPECIMEN. THE RESULTS FOR TWO SENSITIVE CLAYS ARE SHOWN IN A FIGURE. THE SPECIAL STRUCTURE OF HIGHLY SENSITIVE CLAYS APPEARS TO INCREASE THE MODULUS ABOVE THAT FOR LESS SENSITIVE SOILS WITH SIMILAR VOID RATIO AND STATE OF STRESS. REFERENCES: VIBRATION MODULUS OF NORMALLY CONSOLIDATED CLAY, BOBBY O. HARDIN, WILLIAM L. BLACK, ASCE PROCEEDINGS PAPER 5833, MARCH, 1968.
137 citations
TL;DR: In this paper, it was shown that the mechanism and extent of deformation of materials by wedges depends upon the angle of the indenter, and on the elasticity of the material as well as on its yield point.
Abstract: It is shown that the mechanism and extent of the deformation of materials by wedges depends upon the angle of the indenter, and on the elasticity of the indented material as well as on its yield point. The theory for a plastic rigid solid applies only when the angle of the wedge is acute and the indented materials are of low elasticity. At more acute angles, the mechanism of deformation has been shown by Mulhearn to become one of radial compression. It is shown here that this mode of deformation is also favoured when more elastic materials are used. It is also shown that the indentation pressure approximates to that for the expansion of a semicylindrical cavity in an infinite elastic medium with definite yield point and takes the form $P/Y = m \ln (E/Y)+C$ where m and C are constants, E is the Young modulus, Y the yield point in simple extension and P the flow pressure. The value of C depends upon the angle of the wedge. The result is analogous to that obtained by Marsh using a 136$^\circ$ pyramidal indenter, but elastic effects are more important in wedge indentation than when indenting with a pyramid. For blunt wedges and elastic materials, elastic effects predominate in importance; the process can then be regarded as that of the indentation of an ideally elastic solid by a rigid wedge. The pressure distribution on the indentation has been determined. It is shown that elastic theory satisfactorily predicts this distribution of pressure, as well as its mean value. For the indentation of highly elastic materials by acute angled wedges, the elastic and plastic deformations become comparable and the mode of deformation is very complex.
107 citations
TL;DR: The Young's, shear, and bulk moduli of polycrystalline TiB2, ZrB2 and HfB2 were determined from 298 ° to 1300 °K by the sonic resonance technique as mentioned in this paper.
Abstract: The Young's, shear, and bulk moduli of polycrystalline TiB2, ZrB2, and HfB2 were determined from 298 ° to 1300 °K by the sonic resonance technique. All three of these moduli decreased by about 9% over the temperature range considered. The Young's and shear moduli were fitted to Wachtman's empirical equation. The theoretical Soga-Anderson equation was applied to the bulk modulus-temperature data and found to fit the data within 1% despite the variation of the Soga-Anderson constant, δ, with temperature. The Gruneisen constant, γ, was found to remain invariant with temperature while the Poisson's ratio increased with increasing temperature. Debye temperatures were computed from the measured Young's and shear moduli.
94 citations
TL;DR: The addition of antiplasticizers to certain polymers such as Bisphenol A polycarbonate, polysulfone, and polyvinyl chloride results in the elimination of the secondary loss transitions of these polymers as mentioned in this paper.
Abstract: Antiplasticizers are considered to be diluents which when added to polymers result in mechanical property behavior opposite to that of plasticization. The addition of antiplasticizers to certain polymers such as Bisphenol A polycarbonate, polysulfone, and polyvinyl chloride results in the elimination of the secondary loss transitions of these polymers. As a drop in modulus accompanies these transitions, their elimination results in higher tensile strength and tensile modulus. As secondary transitions are commonly associated with ductility and impact strength, their elimination also results in the observed embrittlement characteristics. The addition of anti-plasticizers to polymers also restricts the diffusion of penetrants resulting from the decrease of molecular flexibility in the polymer matrix.
93 citations
TL;DR: In this paper, a polyester resin reinforced with unidirectional R. A. E. carbon fibers or E-glass was subjected to torsional and flexural vibration.
Abstract: Specimens of polyester resin reinforced with unidirectional R. A. E. Type 1 (high modulus) carbon fibers or E-glass were subjected to torsional and flexural vibration. For both types of fibers the ...
73 citations
TL;DR: In this article, a number of polymers have been "cold" extruded (i.e. at temperatures well below their normal melting temperatures) by the application of relatively high pressures.
Abstract: A number of polymers have been “cold” extruded (i.e. at temperatures well below their normal melting temperatures) by the application of relatively high pressures. In all cases extrudates of relatively large cross-sectional area have been produced, and non-circular cross-sections have also been extruded. The extruded products has been evaluated and the results discussed. In general it has been found that whilst extrusion gives an oriented product, the increase in tensile modulus is much less than for a comparably drawn fibre. This phenomenon has been discussed in terms of the changes in crystalline structure produced by extrusion.
51 citations
TL;DR: Calculations of modulus of elasticity for extended-and folded-chain configurations have been compared with the experimental observations of mechanical properties of native cellulosic fibers.
Abstract: Calculations of modulus of elasticity for extended-and folded-chain configurations have been compared with the experimental observations of mechanical properties of native cellulosic fibers. A recent folded-chain proposal is incompatible with the experimental evidence.
TL;DR: In this paper, the effects of irradiation and the addition of boron on carbon fibres derived from polyacrylonitrile were investigated and it was shown that both treatments caused significant increases in the Young's modulus of the fibres, and in some cases increased the fibre strength.
Abstract: WE report some preliminary results from a study of the effects of irradiation and the addition of boron on carbon fibres derived from polyacrylonitrile. Both treatments caused significant increases in the Young's modulus of the fibres, and in some cases increased the fibre strength.
TL;DR: It has been concluded that plastic extensibility cannot he of great importance in longitudinal growth and that one of the primary actions of auxin consists in a loosening of the cell wall matrix.
Abstract: The relationship between Young's modulus and longitudinal growth has been studied on growing segments of etiolated sunflower hypocotyls. The modulus was determined by means of the resonance frequency method. IAA in a concentration of 2.8 10−5 M produces a decrease in the modulus with a time lag of 4 minutes, while an increase in growth is observable only after 6 minutes. Addition of IAA results in a stronger decrease in the modulus if the segments are placed in a solution of 0.1 M mannitol rattier Hum in water. Through plasmometric measurements it has been found that the elastic extensibility is insignificant compared with the growth. After the addition of IAA, there occurs a marked elongation both in 0.1 M mannitol and in water, and at the same time a decrease in the elastic extensibility of the segments is observed. In the growing segments an increased modulus causes an in creased elastic extensibility, a matter which is directly contrary to the relationship found in a physical system with an applied external force. An explanation of this discrepancy has been given. With an excess of calcium the modulus increases, while the elongation decreases. Calcium deficiency implies both a decreased modulus and a decreased growth. With the addition of 10−3 M Ca(NO3)2 to segments raised without calcium the modulus increases after only 10 minutes, while an increase in longitudinal elongation is observable after 30 minutes. With the addition of IAA to the calcium deficient segments the modulus decreases to the same extent as in an optimal supply o f calcium. The results are discussed with reference to other investigations about elasticity and growth. It has been concluded that plastic extensibility cannot he of great importance in longitudinal growth. Time studies of the auxin effect and I he interaction between auxin and calcium have confirmed the hypothesis that one of the primary actions of auxin consists in a loosening of the cell wall matrix. Calcium always increases Youngs modulus and gives the cell wall a more rigid structure. Furthermore, calcium in a certain concentration is necessary for longitudinal growth.
Patent•
05 May 1969TL;DR: In this paper, light weight, strong and lightweight composite re-fractory ARTICLES COMPRISING a PLURALITY of TANTALUM COATED CARBON FIBERS BONDED TOGETHER by an ESSENTIALLY ALUMINUM MATRIX are provided.
Abstract: LIGHT WEIGHT, STRONG COMPOSITE REFRACTORY ARTICLES COMPRISING A PLURALITY OF TANTALUM COATED CARBON FIBERS BONDED TOGETHER BY AN ESSENTIALLY ALUMINUM MATRIX ARE PROVIDED. SUCH COMPOSITE ARTICLES ARE CHARACTERIZED BY A HIGH MODULUS OF ELASTICITY AND ARE ESPECIALLY SUITED AS MATERIALS OF CONSTRUCTION FOR AEROSPACE AND HYDROSPACE VEHICLES AND SYSTEMS.
TL;DR: In this paper, the authors applied the time-temperature superposition principle to yield stress, initial tangent moduli, and relaxation moduli data for all three types of loading.
Abstract: Epoxy–Versamid specimens were loaded in tension, compression, and flexure at different strain rates and temperatures to determine mode of failure, yield stress and strain, and tangent and relaxation moduli. Stress-strain curves were used to define brittle, ductile, ductile-rubbery, and rubbery modes of behavior which prevailed in different temperature-strain rate regions. The time-temperature superposition principle was applied to yield stress, initial tangent moduli, and relaxation moduli data for all three types of loading.
The transition regions, tangent and relaxation moduli, and shift factors were the same in tension, compression, and flexure. Thus the most convenient mode of loading can be used to determine the general time-temperature dependence. The ratio of compressive-to-tensile yield stress was almost constant over the entire ductile region. Flexural yielding data were used to predict yield stress in tension and compression, and stress relaxation master curves were shown to be related to elastic modulus vs. strain rate curves. The yielding phenomenon was interpreted using Eyring's theory of non-Newtonian viscoplastic flow. The apparent activation energy and activation volume were larger for tension than compression. A theory is offered to explain why yielding can occur in a cross-linked system.
TL;DR: In this paper, the temperature dependence of relative modulus observed in filled thermoset, thermoplastic, and polyelectrolyte salt matrices is explained on the basis of induced stresses produced by the differences in the thermal expansion coefficients of the constituent materials.
Abstract: The temperature dependence of relative modulus observed in filled thermoset, thermoplastic, and polyelectrolyte salt matrices is explained on the basis of induced stresses produced by the differences in the thermal expansion coefficients of the constituent materials. The analysis is based on the assumption that the modulus of the matrix in a filled polymer is less than that of the unfilled polymer. The temperature dependence of relative modulus is expressed as a function of the difference in thermal expansion coefficients, the volume fraction, the relative modulus in the unstressed state, and mechanical properties of the phases. Agreement is good between the analysis and experimental results for three systems: epoxy and glass, polyethylene and wollastonite, and a polyelectrolyte salt with mica and asbestos.
Patent•
24 Nov 1969
TL;DR: In this paper, a device for measuring local tension or modulus of elasticity of web comprising a vacuum chamber into which a portion of the width of web is drawn and the deflection of the web into the chamber measured to provide a measurement of the tension and to a pair of such devices having cavities of different widths operating together.
Abstract: A device for measuring local tension or modulus of elasticity of web comprising a vacuum chamber into which a portion of the width of the web is drawn and the deflection of the web into the chamber measured to provide a measurement of the tension and to a pair of such devices having cavities of different widths operating together and the outputs compared to obtain a reading of the local modulus of elasticity of the web being tested.
TL;DR: The dependence on temperature of the tensile modulus in the machine and transverse directions was examined for specimens which were dry, conditioned to 50% R.H., and saturated with water.
Abstract: Samples of 66 nylon were oriented by rolling to produce structures in which the polymer chains are preferentially in the machine direction and the hydrogen bonds are in the transverse direction. Conditioning to 50 or 100% relative humidity (R.H.) produces anisotropic swelling with the transverse direction expanding much less than the other two directions. The dependence on temperature of the tensile modulus in the machine and transverse directions was examined for specimens which were dry, conditioned to 50% R.H., and saturated with water. At high temperatures, the modulus was larger in the transverse direction. At-40°C, it was larger in the machine direction and increased with increasing moisture. The data are interpreted in terms of crystals which have their largest dimension in the hydrogen bond direction.
Journal Article•
TL;DR: In this paper, the authors investigate the physical behavior of OSAKA MARINE CLAY under the stress relaxation test and show that for a given given increase in the strain, both the initial stress and the fully relaxed stress relaxations decrease with increasing temperature.
Abstract: THE MECHANICAL BEHAVIOR OF CLAY IS INVESTIGATED FROM THE THERMAL BEHAVIOR OF ITS ELASTICITY AND VISCOSITY. THE MECHANICAL BEHAVIOR OF THE CLAY SKELETON WHOSE STRESS AND STRAIN ARE EXPRESSED BY A LINEAR RELATION WITH A PARAMETER OF TIME HAS BEEN SIMULATED BY A MATHEMATICAL MODEL. VISCOSITY OF CLAY IS INFLUENCED BY TEMPERATURE AS SUGGESTED IN THE FLOW BEHAVIOR AT VARIOUS TEMPRATURES. THE EFFECT OF TEMPERATURE ON THE ELASTICITY OF CLAY CAN BE INVESTIGATED BY THE BEHAVIOR ON THE STRESS RELAXATION TESTS AT VARIOUS TEMPERATURES. THE EFFECT OF TEMPERATURE ON THE ELASTIC MODULI IN THE MODEL IS INVESTIGATED. RESULTS OF THE STRESS RELAXATION TESTS SHOW THAT FOR A GIVEN INCREMENT OF STRAIN BOTH THE INITIAL STRESS AND THE FULLY RELAXED STRESS RELAXATION DECREASES WITH INCREASING TEMPERATURE. THE BEHAVIOR OF OSAKA MARINE CLAY UNDER THE STRESS RELAXATION TEST IS WELL PREDICTED BY THE MECHANICAL MODEL. ELASTIC MODULI DECREASE WITH THE INCREASE IN TEMPERATURE.
TL;DR: In this article, the authors show that the creep of mixes having the same workability and strength at loading is not affected by the presence or absence of entrained air, so that the approximate linear relationship between creep and stress/strength ratio previously found for plain concrete applies also to air-entrained concrete.
Abstract: Synopsis The creep of mixes having the same workability and strength at loading is shown not to be affected by the presence or absence of entrained air, so that the approximate linear relationship between creep and stress/strength ratio previously foundfor plain concrete applies also to air-entrained concrete. A correlation between specific creep and the modulus of elasticity at loading is shown to exist for the full range of concrete, mortar and neat cement paste mixes tested. Air-entrained concrete fits the same curve as that obtained for plain mixes of the same strength because both have the same total void content (air, capillary pores and gel pores). This void content is of fundamental importance in understanding the mechanical properties of concrete.
TL;DR: In this article, a theory of displacements at slit cracks under shear due to the spread of plastic deformation from the tips is proposed to analyze the nonlinearity of the stress-strain curves of graphite under compression.
TL;DR: In this paper, the effect of various factors such as mix proportion, water-cement ratio, age and curing conditions on compressive strength, dynamic modulus of elasticity and damping characteristics of plain concrete is given.
TL;DR: In this paper, a regenerative drive system for kilohertz acoustic measurements in alkali halide crystals is described, where field effect transistors are used as gain control elements to keep the strain-amplitude of mechanical vibrations constant during experiments in which internal friction and modulus are changing.
Abstract: A regenerative drive system is described for kilohertz acoustic measurements in alkali halide crystals In the system field effect transistors are used as gain control elements to keep the strain-amplitude of mechanical vibrations constant during experiments in which internal friction and modulus are changing Discussion is given of the main features of the design of the equipment, its testing and calibration and its application to experiments involving effects of nuclear radiation on alkali halide crystals
Journal Article•
TL;DR: In this article, a method based on ELASTICLAYERED theory and programmed for a high-speed computer was developed for determining the effect of VARIOUS FACTORS on Equivalent SINGLE-WHEEL LOADS, USING EQUAL INTERFACE DEFLECTION CRITERION.
Abstract: A METHOD BASED ON ELASTIC LAYERED THEORY AND PROGRAMMED FOR A HIGH-SPEED COMPUTER WAS DEVELOPED FOR DETERMINING EQUIVALENT SINGLE-WHEEL LOADS FOR DUAL WHEELS. IT WAS FOUND THAT EQUIVALENT SINGLE-WHEEL LOADS BASED ON EQUAL VERTICAL DEFLECTION AT THE PAVEMENT-SUBGRADE INTERFACE WERE GENERALLY GREATER THAN THOSE BASED ON EQUAL VERTICAL STRESS OR EQUAL SURFACE DEFLECTION. THE EFFECT OF VARIOUS FACTORS ON EQUIVALENT SINGLE-WHEEL LOADS WAS INVESTIGATED, USING EQUAL-INTERFACE DEFLECTION CRITERION. IT WAS FOUND THAT THE RATIO BETWEEN THE TOTAL LOAD ON DUAL WHEELS AND THE EQUIVALENT SINGLE-WHEEL LOAD DEPENDS ON THREE FACTORS: PAVEMENT THICKNESS, WHEEL SPACING, AND MODULUS RATIO, WHICH IS THE RATIO OF THE MODULI OF ELASTICITY OF PAVEMENT AND SUBGRADE. CHARTS THAT GIVE THE INTERFACE DEFLECTION UNDER A CIRCULAR LOAD FOR VARIOUS PAVEMENT THICKNESSES, OFFSET DISTANCES, AND MODULUS RATIOS ARE PRESENTED SO THAT THE EQUIVALENT SINGLE-WHEEL LOAD FOR ANY GIVEN LOADING AND PAVEMENT CONDITION CAN BE DETERMINED. AN IMPORTANT FACT REVEALED BY THIS STUDY IS THAT THE EQUIVALENT SINGLE-WHEEL LOAD INCREASES APPRECIABLY WITH THE INCREASE IN MODULUS RATIO. THE CURRENT METHOD OF ASSUMING THAT PAVEMENTS ARE HOMOGENEOUS MEDIA WITH A MODULUS RATIO OF UNITY ALWAYS GIVES AN EQUIVALENT SINGLE-WHEEL LOAD THAT IS TOO SMALL AND IS NOT IN LINE WITH THE FINDINGS OF THE WASHO ROAD TEST. /AUTHOR/
TL;DR: In this article, three modes of behavior prevailing at different temperature-strain-rate regions and associated with brittle, ductile and rubbery failure modes were found to be consistent with Eyring's formulation for non-Newtonian viscoplastic flow, leading to the evaluation of the apparent activation energy and activation volume for the two epoxy systems tested.
Abstract: : Epoxy-versamid specimens were loaded in tension up to failure at different constant strain-rates and temperatures. Results revealed three modes of behavior prevailing at different temperature-strain-rate regions and associated with brittle, ductile and rubbery failure modes. The ductile region was found to be confined within a narrow band on the temperature-strain-rate plane, and is characterized by a yield plateau in the stress-strain curve and by linear dependence of yield stress on log strain rate and temperature. Yield strain seems to be almost unaffected by strain-rate, but decreases slightly with temperature rise. Analysis indicated that experimental data within the ductile region are consistent with Eyring's formulation for non-Newtonian viscoplastic flow. It leads to the evaluation of the 'apparent activation energy' and activation volume for the two epoxy systems tested. Comparison with previous work indicates that the above parameters as well as yield stress and elastic modulus tend to increase with the decrease of versamid content in the resin.
01 Jun 1969
TL;DR: In this article, the complex dynamic Young's and shear moduli, loss factor and Poisson's ratio are presented for naturally compacted glacial snow through a density range of 0.4 to 0.9 g/cu cm.
Abstract: : The complex dynamic Young's and shear moduli, loss factor and Poisson's ratio are presented for naturally compacted glacial snow through a density range of 0.4 to 0.9 g/cu cm. A frequency dependence of the moduli and its effect on the computation of Poisson's ratio is demonstrated. Considerable scatter is exhibited in the loss factor measurements; however, indications are that the loss factors have negligible effect on the modulus computations. (Author)
14 May 1969
TL;DR: The change in modulus of elasticity with temperature has been examined between -70 and +375C in the dry state for one paper of cotton linters and two bleached pine kraft papers as mentioned in this paper.
Abstract: : The change in modulus of elasticity with temperature has been examined between -70 and +375C in the dry state for one paper of cotton linters and two bleached pine kraft papers The modulus of elasticity was evaluated for the machine and cross directions by a sonic pulse technique, subsequent to 4 seconds of thermostating in a plane press nip Four temperature ranges with a rapid change in modulus of elasticity appear indicating secondary transitions, before a considerable final fall of the modulus A previous heat treatment of the papers at 190C, ie a thermal autocrosslinking of cellulose chains, appeared to move transition II upwards and the other three transitions slightly downwards From a comparison of untreated and heat-treated papers, the glass transition temperature of dry cellulose was estimated to 230C (Author)
TL;DR: In this article, the structural properties of columnar specimens prepared by total oxidation of metallic copper have been studied as a function of bend rate and temperature, and the modulus of elasticity of cuprous oxide was constant from room temperature to 500°C and thereafter decreased linearly with increasing temperature to at 800°C.
Abstract: The morphology of growth of on Cu has been studied using scanning electron microscopy. The mechanical properties of columnar specimens prepared by total oxidation of metallic copper have been studied as a function of bend rate and temperature. The modulus of elasticity of cuprous oxide was constant from room temperature to 500°C and thereafter decreased linearly with increasing temperature to at 800°C. The oxide exhibited a pseudo brittle‐ductile transformation at 360°C and 400°–500°C when slow and fast bending rates, respectively, were used. There was also a maximum strength peak at a critical temperature related to the onset of plastic deformation. Load‐deflection functions indicated large amounts of plastic deformation and in the light of fracture surface observations this can be interpreted in terms of a slow cleavage mechanism.