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Showing papers on "Young's modulus published in 1974"


Journal ArticleDOI
TL;DR: The elastic moduli for human and bovine bone specimens were determined by compression and tension tests and compared and no statistically significant difference was found between the moduli determined in the two loading modes.

509 citations


Journal ArticleDOI
TL;DR: Nacreous structure, which is very strong but not widely used, apparently evolved earlier than the less strong but widely used crossed-lamellar structure.
Abstract: Pieces of shell from 19 species of molluscs exhibiting various microstructures were tested for tensile strength, modulus of elasticity in bending and modulus of rupture. In tensile strength most shells with cross-foliated, foliated, homogeneous and crossed-lamellar structures did not exceed 60 MNm 2 but prismatic and nacreous structures often exceeded this value. Nacreous structure was generally superior to all others in modulus of rupture tests; that of Turbo being about equal to bone. Values of modulus of elasticity were more uniform between structures. There is a general relation between mechanical properties, microstructure and the life style of each animal. Nacreous structure, which is very strong but not widely used, apparently evolved earlier than the less strong but widely used crossed-lamellar structure.

262 citations


Journal ArticleDOI
TL;DR: In this paper, the elastic properties of copper have been compiled and reviewed, including Young's modulus, the shear modulus and the bulk modulus of copper, and a few theoretical numbers are included.
Abstract: 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.

211 citations


Journal ArticleDOI
TL;DR: In this article, a theoretical analysis using finite element methods has been applied to oriented short-fiber composites and spherical particle composites in order to predict the influence of a finite layer at the interface on mechanical properties.
Abstract: A theoretical analysis using finite element methods has been applied to oriented short-fiber composites and spherical particle composites in order to predict the influence of a finite layer at the interface on mechanical properties. In this study the interfacial layer has been modeled by assuming that a layer surrounds the interface and that this layer has a modulus of elasticity different than both the fiber and the matrix. The stress distribution near the interface has been determined as a function of the elastic constants of the interface layer and the interface layer volume fraction. This analysis has also been performed for two volume fractions of fibers and two fiber length to diameter ratios. From this stress distribution, the composite modulus and toughness have been determined as a function of interface modulus. It is theoretically shown that the toughness, measured by amount of strain energy absorbed, can be maximized by controlling the interface modulus. Furthermore, recent experimental results appear to verify the theory.

185 citations


Journal ArticleDOI
TL;DR: In this article, the bifurcation problem governing the onset of axisymmetric necking in a circular cylindrical specimen in uniaxial tension is analyzed. But the authors do not consider the case where one end is subject to a prescribed uniform axial displacement relative to the other and both ends are shear free.
Abstract: The bifurcation problem governing the onset of axisymmetric necking in a circular cylindrical specimen in uniaxial tension is analysed. The specimen is made of an incompressible elastic/plastic material. One end is subject to a prescribed uniform axial displacement relative to the other and both ends are shear free. The true stress at bifurcation is greater than the stress at which the maximum load is attained by an amount which depends on (a) the radius to length ratio of the specimen, (b) the ratio of the elastic shear modulus to the tangent modulus, and (c) the derivative of the tangent modulus with respect to the stress. Bifurcation takes place immediately following attainment of the maximum load when the specimen is sufficiently slender.

135 citations


Journal ArticleDOI
TL;DR: In this paper, the behavior of anisotropic compact bone in tension at a range of strain rates was examined and the modulus of elasticity, breaking stress and breaking strain were found to vary with strain rate.
Abstract: The paper examines the behavior of anisotropic compact bone in tension at a range of strain rates. Specimens of fresh bovine bone were loaded at strain rates between. 001 and 200 sec−1. This bone was shown to exhibit considerable plasticity throughout the range, except when tested in a direction normal to the long axis. The modulus of elasticity, breaking stress and breaking strain were found to vary with strain rate. There is a maximum energy absorbtion capability at a strain rate of .1 sec−1.

131 citations


Journal ArticleDOI
Lawrence E. Nielsen1
TL;DR: In this paper, the theory of elastic moduli of composite materials in which an inversion of the phases can occur is reviewed and the applicability of the theoretical equations is illustrated for four systems of block polymers and polyblends.
Abstract: The theory of the elastic moduli of composite materials in which an inversion of the phases can occur is reviewed. The morphology of the system and the packing fraction of the dispersed phase are important in determining the moduli. The applicability of the theoretical equations is illustrated for four systems of block polymers and polyblends. In three of the systems, phase inversion occurs. Agreement between theory and experiment is good, and where the morphology of the composites is known, the moduliagree with the values expected for that morphology.

121 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe a mechanism of load transfer from matrix to fibre about single short fiber models. And they predict Young's modulus of short fibre-reinforced materials provided that the orientation of the fibres obeys a certain rule.

114 citations


Journal ArticleDOI
01 Sep 1974

97 citations


Journal Article
TL;DR: In this paper, the effects of non-constant state of stress on the observed resilient properties of granular materials were identified based on the current literature, which were later investigated during the laboratory phase, were density level, type of material, load duration, and number of load repetitions.
Abstract: Present methods of determining the resilient parameters (modulus of deformation and Poisson's ratio) of granular materials for use in the analysis of pavement structures subjected to moving wheel loads are based on the results of laboratory repeated-load triaxial tests in which the minor principal stress (chamber pressure) is held constant. However, as a wheel load moves over an element of an actual pavement structure, the element is subjected to both time-dependent lateral and vertical stresses. The purpose of this study was to determine the effects of this nonconstant state of stress on the observed resilient properties of granular materials. Based on the current literature, certain factors thought to affect the resilient properties of granular materials were identified. Among these factors, which were later investigated during the laboratory phase, were density level, type of material, load duration, and number of load repetitions. Nonlinear, finite-element analyses of typical pavement sections were used to establish typical horizontal and vertical stress pulses. The characteristics stress pulses were used to test specimens during the laboratory investigation. It was shown that factors such as load duration, stress sequence, and number of repetitions have negligible effects on the resilient parameters. Nonlinear regression analyses of the laboratory data indicated that the resilient modulus is significantly influenced by the state of stress in the material and may be expressed as a function of the first invariant of the stress tensor. Poisson's ratio may be expressed as a function of the principal stress ratio. The effects of density and material type are small compared with the stress-dependent effects. The resilient modulus determined by the constant-confining-pressure test was found to vary insignificantly from that determined by the variable-confining-pressure test. However, the constant-confining-pressure test data greatly overestimate Poisson's ratio because of the anisotropic nature of the material and the greater volume change that is observed in that type of test.

86 citations


Journal ArticleDOI
TL;DR: The results are sufficiently promising to warrant additional long-term experiments investigating this concept of internal fixation, and a new composite plate made of less rigid material but with similar geometry to stainless steel plates may promote fracture union without the complication of osteopenia.
Abstract: The use of conventional rigid metal plates (modulus of elasticity 30 × 106 psi) for internal fixation of difficult long bone fractures may paradoxically weaken the fractured bone through a process of osteoporosis secondary to protection of the bone from stress. The hypothesis being studied which has stimulated the present work is that a new composite plate made of less rigid material but with similar geometry to stainless steel plates may promote fracture union without the complication of osteopenia. This new composite material has a modulus of elasticity similar to that of bone (approximately 3 × 106 psi) which is more than an order of magnitude lower than that of stainless steel, yet the fracture strength of this new composite material (35,000 psi) is approximately one-half that of stainless steel. The ability to fix diaphyseal fractures by composite plates was studied by implanting these plates in the left (experimental) radii of six dogs with transverse mid-shaft osteotomies. The right (control) radii had similar transverse osteotomies, but were plated by conventional metal plates equal in size to the new composite plates. Four months postsurgery, all experimental and control fractures had healed. Biomechanical tests of the excised radii using a torsional loading apparatus showed there were no significant differences in strength, fracture energy, angular deformation, or maximum shearing stress when comparing the experimental to the control radii. The results are sufficiently promising to warrant additional long-term experiments investigating this concept of internal fixation.

Proceedings ArticleDOI
01 Feb 1974
TL;DR: In this paper, the dent resistance of doubly curved rectangular panels in various steels and aluminum alloys was studied and an empirical equation was developed that relates dent resistance to the yield strength, modulus of eleasticity, metal thickness, and panel geometry of stiffness.
Abstract: The dent resistance of doubly curved rectangular panels in various steels and aluminum alloys was studied. Dent depth on the order of magnitude of the panel thickness was determined. An empirical equation was developed that relates dent resistance to the yield strengths, modulus of eleasticity, metal thickness, and panel geometry of stiffness. Dent resistance increases with an increases in yield strength, thickness and panel radii of curvature, but decreases with an increase in modulus of elasticity and stiffness.

Journal ArticleDOI
TL;DR: In this paper, a three-dimensional finite element analysis (SAFE-3D) was used to determine the internal stresses in an ordered spherical particle composite and the Young's modulus has been calculated from a knowledge of these stresses and the applied deformation.

Journal ArticleDOI
TL;DR: In this paper, reaction-bonded SiC loses nearly 50% of its fracture strength when exposed to neutron irradiation, and the damage occurs soon after exposure and levels out with continuing exposure up to 3 × 10 21 n/cm 2.



Journal ArticleDOI
TL;DR: The Young's modulus of longitudinal bovine tibia compact bone specimens (both ‘wet’ and ‘dry’) has been determined with two different microstrain measuring techniques.

Journal ArticleDOI
TL;DR: In this article, a pulse echo technique using thin line ultrasonics has been used to measure the variation with carbon content of austenite, and the results indicate the extent of the error which arises when the thermodynamic functions calculated from models involving constant interaction energies are compared with exparimantal thermodynamic data measured at constant pressure.

Journal ArticleDOI
TL;DR: In this paper, a theoretical solution for the stress and strain distribution within elastic cylindrical specimens, as a function of the friction at the interface of the specimen and the machine platens, was derived.



Journal ArticleDOI
TL;DR: In this article, a composite resonator was used to determine polycrystalline elastic moduli for TiC, TiC-26% VC, VC-22% TiC and VC with carbon content close to 0.84.
Abstract: Polycrystalline elastic moduli have been determined for TiC, TiC-26% VC, VC-22% TiC and VC using a composite resonator. Carbon to metal ratios were in all cases close to 0.84. Room temperature moduli variations with alloy composition are discussed and by comparison with other data the order of magnitude of modulus variation with carbon content is determined for TiC. The temperature dependence of Young's modulus for TiC and VC are determined in the range 20 to 1600° C. Correlations are sought with hardness data.


Journal ArticleDOI
TL;DR: In this paper, urea-bonded particleboards with three resin levels and three specific gravity values were made in the laboratory for modulus rupture, modulus of elasticity, and internal bond strength tests were conditioned at 14 relative humidity values over the range 13-97 per cent.
Abstract: For this study, urea-bonded particleboards with three resin levels and three specific gravity values were made in the laboratory. Specimens for modulus of rupture, modulus of elasticity, and internal bond strength tests were conditioned at 14 relative humidity values over the range 13–97 per cent. Results for the three mechanical properties were fitted to cubic equations in moisture content with a high degree of accuracy (correlation coefficients of over 0.99 in most cases).

01 Jan 1974
Abstract: To achieve full utilization of each har­ vested tree, interest centers on use of all of the tree components. Here the objective was to de te rmine the in f luence o f the morphological characteristics of pulp fiber from 12 western U.S. softwood species, representative of a wide range of fiber. The effect of the morphology of the wood pulp fiber as distinguished from that of the wood fiber is emphasized because differences in performance of fiber-based products are traced to the pulp fiber. Interrelationships of fiber morphology and pulp sheet properties are discussed. The results indicate that it is not possible to fully char­ acterize the performance of a pulp by a single morphological characteristic and that the morphological characteristics significantly influence strength properties of sheets.

Journal ArticleDOI
TL;DR: In this article, the shear modulus of a pressurized cylindrical shell containing a longitudinal crack is evaluated from the measured Young's moduli and the Poisson's ratios rather than being an independent material constant.
Abstract: A pressurized cylindrical shell containing a longitudinal crack is considered. The shear modulus of the sheet may be evaluated from the measured Young's moduli and the Poisson's ratios rather than being an independent material constant. Two examples, one for a mildly orthotropic (titanium) and the other for a strongly orthotropic (graphite) material approximately satisfying the condition of special orthotropy are given. The results show that the stress intensity factors are rather strongly dependent on the degree of orthotropy.

Journal ArticleDOI
TL;DR: In this paper, a 1 kbar fluid compressibility apparatus was used to determine the bulk compressibility moduli of samples of some epoxy resin systems and combined with Young's modulus of the same materials has produced some accurate values of Poisson's ratio.
Abstract: A 1 kbar fluid compressibility apparatus has been used to determine the bulk compressibility moduli of samples of some epoxy resin systems. Combination with recent data on Young's modulus of the same materials has produced some accurate values of Poisson's ratio.

Journal ArticleDOI
G. Hausch1
TL;DR: In this paper, measurements of the temperature dependence of Young's modulus of Fe-Pt alloys (25-29 at% Pt) both in the ordered and disordered states are presented.
Abstract: 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.


Patent
22 Oct 1974
TL;DR: In this paper, relief plates for flexographic printing comprising a relatively soft elastomeric base (U) having a modulus of elasticity of from 10 to 200 kg/cm 2 and a thickness of from 0.5 to 6 mm and, firmly bonded thereto, a thin, relatively hard, difficultly soluble intermediate layer Z having a 1 × 10 3 to 2.1 × 10 6 kg/mm 2 and thickness from 5 to 500 μ, were described.
Abstract: The invention relates to relief plates for flexographic printing comprising a relatively soft elastomeric base (U) having a modulus of elasticity of from 10 to 200 kg/cm 2 and a thickness of from 0.5 to 6 mm and, firmly bonded thereto, a thin, relatively hard, difficultly soluble intermediate layer Z having a modulus of elasticity of from 1 × 10 3 to 2.1 × 10 6 kg/cm 2 and a thickness of from 5 to 500 μ and, firmly bonded to said intermediate layer Z, a relief layer P' consisting of a photocrosslinked elastomeric mixture having a modulus of elasticity of from 30 to 2000 kg/cm 2 and a thickness of from 200 to 300 μ, the modulus of elasticity of the photocrosslinked relief layer P' being the same as or higher than that of the base U and the neutral surface of the relief plate lying in or near the intermediate layer Z. The invention also relates to photosensitive laminates for the production of such plates.