Showing papers on "Tensile testing published in 1974"
Journal Article•
TL;DR: In this article, the double-punch test was used to measure the tensile strength of concrete and the effect of several additional parameters, such as the rate of stressing during the test and the effects of lightweight as well as regular concrete.
Abstract: The tensile strength of concrete is most commonly measured by the indirect split-cylinder test. Recently a new test, the double-punch test, has been proposed. The new test method had undergone preliminary experimental study to determine the testing procedure that would yield the most reliable and consistent results. However, further study was needed. By using the previously recommended procedure, the effect of several additional parameters on the tensile strength was studied. These parameters include the rate of stressing during the test and the effect of lightweight as well as regular concrete. The effects of the molds, machine lubricant, and testing machine are also being studied. Analysis of these results has led to a more thorough understanding and greater applicability of the new tensile test.
78 citations
TL;DR: The optimum conditions for butt fusion welding certain grades of polyethylene, polybutene-1 and polypropylene pipes have been determined on the basis of tensile test results as discussed by the authors.
Abstract: The optimum conditions for butt fusion welding certain grades of polyethylene, polybutene-1 and polypropylene pipes have been determined on the basis of tensile test results. The effect of the welding bead has been discussed and the conclusion reached that removal of the welding beads enables a clearer picture to be obtained of weld performance when this is judged from a tensile test. An examination of the microstructures of each weld has shown the presence of different zones. The importance of these zones is discussed in relation to the short- and long-term strength of the welds.
49 citations
TL;DR: In this paper, a series of experiments carried out on concrete under uniaxial tensile stress, using a test method developed previously, were described, including the effect of mix proportions and curing conditions upon the short-term failure stress and strain and upon the tensile creep under a load of 35% of the ultimate short-time strength.
Abstract: Synopsis This paper describes a series of experiments carried out on concrete under uniaxial tensile stress, using a test method developed previously. The properties assessed include the effect of mix proportions and curing conditions upon the short-term failure stress and strain and upon the tensile creep under a load of 35% of the ultimate short-term strength. The effect of variable humidity states upon the tensile creep was also investigated, and the results interpreted from the viewpoint of creep hypotheses for compressive loading. Where possible, the observed effects are related to the microstructure of cement gel. Finally, the effects upon creep of the level of loading and of the long-term strength of concrete in tension have been determined, and compared with the established behaviour in compression.
49 citations
TL;DR: In this article, a study of a typical core material is performed to investigate the various factors influencing the tensile strength and stress-strain relationships in tension, including water content, compactive effort, rate of loading, and change of plasticity.
Abstract: An analysis of cracking of clay cores of earth dams requires an understanding of behavior of soils in tension. A study of a typical core material is performed to investigate the various factors influencing the tensile strength and stress-strain relationships in tension. Studied are effects of water content, compactive effort, rate of loading, and change of plasticity by adding bentonite. Various experimental procedures for tensile tests are examined with the indirect tensile test chosen as the most convenient. The experimental technique used with this type of test is described in detail. The test results indicate that the tensile strength of a typical low to medium plasticity core soil can be assumed to be zero for practical purposes of design and analysis. The stress-strain properties are, however, needed if attempts in design are made to minimize the cracking potential of an earth dam and if lateral extensometer readings are to be interpreted.
40 citations
TL;DR: The new method was found to give rapid, reproducible results which agreed well with tensile strength values obtained from diametral compression, but tablets invariably failed in tension using the new method.
36 citations
TL;DR: Three methods of measuring tensile strengths of compacted powders are described and a method of estimating both the internal cohesion and the exponent of the Warren-Springs equation from shear cell data is described.
36 citations
TL;DR: This paper is concerned with the determination of the mechanical properties of connective tissues by subjecting them to uniaxial tensile loading, and typical results of constant extension rate and relaxation tests are presented.
Abstract: This paper is concerned with the determination of the mechanical properties of connective tissues by subjecting them to uniaxial tensile loading. The emphasis is upon techniques which can be applied to a wide variety of tissues, and particular attention is paid to such problems as specimen form, cross-sectional-area measurement, gripping the specimen, providing a suitable test environment and measuring specimen extension.
27 citations
TL;DR: In this paper, problems associated with moisture in polycarbonate during molding are described in detail, and proper drying techniques prior to molding can eliminate the overall effects of moisture on the physicochemical properties of polycarbonates.
Abstract: Proper drying techniques prior to molding can eliminate the overall effects of moisture on the physicochemical properties of polycarbonate. Problems associated with moisture in polycarbonate during molding are described in detail. Moisture absorption is very rapid with the maximum allowable moisture content of 0.03 percent reached within 30 minutes at 49 percent RH and 75°F. Molding with excess moisture content causes a chemical and physical degradation resulting in reduction in tensile impact strength, tensile elongation, ultimate tensile strength, proportional limit and molecular weight. New and existing techniques and procedures for degradation detection were investigated, such as intrinsic viscosity, infrared spectrometry, and thermal methods of analysis. Gel permeation chromatography (GPC) proved the most satisfactory. GPC provided information on the average molecular weight and polydispersity.
26 citations
TL;DR: In this paper, the authors measured tensile strains at failure in pure tension and in bending for several high-modulus fibers, and fiber loop strength was determined at a range of loop curvatures for the same materials.
Abstract: Tensile strains at failure in pure tension and in bending were measured for several high-modulus fibers, and fiber loop strength was determined at a range of loop curvatures for the same materials. Brittleness in bending is not necessarily associated with high tensile modulus and low breaking strain if the fiber is capable of yielding in compression.
23 citations
TL;DR: In this article, it is shown that the differences between any of the empirical stress/strain equations represent the least significant of the errors in describing the actual stress and strain behaviour of an element of material under sheet-forming conditions.
Abstract: Perhaps the area in which a detailed knowledge of stress/strain relations is most important is that of sheet forming. It is true that the precise form of the stress/strain equation should be known to assist analyses of sheet-forming processes. However, in the present context, the proposition is that such data can be obtained from a tensile test. This contribution examines that proposition especially under the circumstance likely to prevail in sheet forming that the material is anisotropic. The anisotropy may be crystallographic in origin or may otherwise arise from the pre-strain history. It is concluded that the differences between any of the empirical stress/strain equations represent the least significant of the errors in describing the actual stress/strain behaviour of an element of material under sheet-forming conditions. The importance of considering the total states of stress and strain is illustrated by analysing an example from the literature due to Richards.
22 citations
TL;DR: In this paper, the authors measured the stress wave energy released from notched specimens of structural steel in order to compare it with the recently proposed J-integral which takes account of the effect of large plastic deformation around the crack tip in ductile materials.
Abstract: The stress wave energy released from notched specimens of structural steel was measured in order to compare it with the recently proposedJ-integral which takes account of the effect of large plastic deformation around the crack tip in ductile materials. Very close agreement was observed between theJ-integral and the differential stress wave energy released. This suggests that the increment of the stress wave energy released is proportional to the decrement of the work done on the specimen during tensile testing under the plane stress condition.
TL;DR: In this paper, the influence of the mosaic block structure of bulk-crystallized high-density polyethylene upon deformation within the elastic limit and upon fatigue phenomenon has been extensively studied in the temperature range of the α relaxation mechanism.
Abstract: The influence of the mosaic block structure of bulk-crystallized high-density polyethylene upon deformation within the elastic limit and upon fatigue phenomenon has been extensively studied in the temperature range of the α relaxation mechanism. The magnitude of elastic limit, estimated from two models involving a tilt sliding mechanism and a simple tension mechanism, was compared with experimental results obtained using a tensile tester and a dynamic viscoelastometer at various temperatures of measurement. The two models for onset of deformation are applied on the assumption that the intermosaic block region is selectively affected by strain without any structural change occurring in the mosaic block crystalline core. Also, dynamic mechanical properties were obtained on specimens subject to an increasing number of fatigue cycles. The variation of E'1, max, attributed to deformation processes of the intermosaic block region, is strongly affected by slight elongation and by fatigue cycling of the ...
TL;DR: In this article, a numerical stress solution which considers the difference between compressive and tensile moduli with respect to tensile strength, tensile stress-strain relationship, is developed, and the magnitude of errors associated with the incorrect assumption of equal modulus in tension and comp...
Abstract: Analysis and design of impermeable cores of earth dams against cracking require knowledge of the tensile strengths and tensile stress–strain relationships of the concerned soils. The same is needed for any stress and deformation analysis of an earth structure when a portion of it is expected to be in tension. In order to investigate behavior of soils in tension the Brazilian tensile test has been employed and found advantageous over other methods. However the interpretation of results of this test is involved because of the biaxial stress conditions existing at the center of the test specimen. Neglecting this fact leads to erroneous evaluation of the test results, particularly if the moduli in tension and compression differ. A numerical stress solution which considers the difference between compressive and tensile moduli with respect to tensile strength and tensile stress–strain relationship is developed. The magnitude of errors associated with the incorrect assumption of equal modulus in tension and comp...
TL;DR: The applicability of the split tensile test for the measurement of the tensile strength of cohesive soils is discussed in this paper, where the results of unconfined compression tests and split tensiles tests on cohesive soils compacted dry of optimum are presented.
TL;DR: In this paper, the variations of tensile and compressive yield stresses and Young's modulus of oriented poly(vinyl chloride) sheet with direction and with degree of orientation, represented by birefringence, are shown.
TL;DR: In this paper, an unconfined direct tension test, either strain controlled or load controlled, is described, which can be used to determine the tensile (total) stress-strain characteristics of compacted clays.
Abstract: Although problems associated with total stress tension arise in soil structures such as earth embankments and multilayer pavements, no standard tension test for soils exists. An unconfined direct tension test, either strain controlled or load controlled, is described, which can be used to determine the tensile (total) stress-strain characteristics of compacted clays. The overall tensile strains in the specimen are determined by observing the displacement of two surface markers spiked into the specimen with a displacement measuring optical device (DMOD) capable of measuring to one-micrometer displacement. An alternative radiographic technique of monitoring strains has shown that the distribution of average tensile strains in the specimens is substantially uniform. Moreover, the failure of the tension specimen occurs in midsection, indicating a uniaxial transmission of tensile force to the specimen. Comparison of standard triaxial unconfined compression tests with unconfined tension tests shows that elastic moduli are not equal in compression and tension for compacted clays at a given moisture content.
TL;DR: In this article, the influence of sorption of fluids of differing molecular size on the strength and tensile creep of desiccated concrete and mortar is investigated, and it is shown that the desicated tensile strength is significantly reduced by sorption in accordance with the molecular sieve concept; compressive and splitting tensile strengths are also reduced but to a lesser extent.
TL;DR: In this article, it is shown that the usual percent elongation in a 2-in. gage length of a standard rectangular coupon is not a consistent measure of ductility and that reduction in area is difficult to measure for sheet and strip steel specimens.
Abstract: Ductility is essential for the fabrication and adequate performance of cold-formed steel structures. For defining safe minimum values of ductility, it is first necessary to develop reliable ductility measurements. It is shown that the usual percent elongation in a 2-in. gage length of a standard rectangular coupon is not a consistent measure of ductility and that reduction in area is difficult to measure for sheet and strip steel specimens. Distinction is made between uniform elongation observed in a specimen over a length outside the fracture zone, and local elongation measured over a short length across the fracture. The separate and complementary roles of uniform and local ductility are presented. Several measures for these two distinct properties are described. Two methods for separately measuring uniform and local ductility by minor modifications of the standard ASTM tension test are proposed.
01 Aug 1974
TL;DR: In this paper, the anisotropy of ductile fracture in AISI 1045 hot-rolled steel plates was determined using the upset test method, where the tensile stresses in the respective tests are in the same direction relative to the inclusion orientation.
Abstract: Upset testing of cylindrical specimens generates circumferential tensile stresses at the barreled surfaces. These stresses can be utilized in the same manner as the tensile stresses in the tension test to evaluate the ductility of materials. Using the upset test method, the anisotropy of ductile fracture in AISI 1045 hot-rolled steel plates was determined. Ductility parallel to the plane of inclusions is found to be ≈ 50 pet higher than that perpendicular to the inclusions. It is shown that the local surface strains at fracture in upset testing correlate well with the true zero-gage-length fracture strain in tension testing, provided the tensile stresses in the respective tests are in the same direction relative to the inclusion orientation. Thus, compression tests parallel to the inclusion direction, which generate tensile stresses perpendicular to the inclusions, can be utilized to measure ductility transverse to the fiber of wrought materials. This is particularly useful in determining the short transverse or through-thickness ductility in hot-rolled or forged materials having thin sections.
TL;DR: In this paper, the authors used micromechanical analyses and taking into consideration the highly anistropic crystallo graphic structure of graphite, possible explanations for the observed properties degradation have been formulated.
Abstract: The increasing interest in utilizing carbonaceous-fiber-reinforced carbon matrix materials in high temperature structural applications has resulted in the generation of an increasing amount of experimental data, primarily for unidirectionally reinforced systems. While the longitudinal tensile strength and stiffness properties presently being achieved are attractive relative to those of unreinforced carbonaceous materials such as bulk graphite, they remain well below their apparent potential. Utilizing micromechanical analyses and taking into consideration the highly anistropic crystallo graphic structure of graphite, possible explanations for the observed properties degradation have been formulated. Suggestions for modifying the fabrication and thermal processing as a means of improving axial properties, and tensile strength in particular, are presented.
TL;DR: In this article, the effect of irradiation at 573 and 723 K on the properties of α-annealed material was investigated and the mechanical properties of the alloy Zr-1.14% Cr-0.1% Fe in several metallurgical conditions were reported.
01 Jan 1974
TL;DR: In this paper, the tensile and elastic properties of highway pavement materials were investigated using indirect tensile test and the results of the test were obtained from four types of pavement materials obtained from recently constructed highway pavements.
Abstract: This report describes the results of an investigation of the tensile and elastic properties of highway pavement materials. Cores of four types of materials obtained from recently constructed highway pavements were obtained and tested. Experimental estimates of the tensile and elastic properties (tensile strength, modulus of elasticity, and Poisson's ratio) of these materials were made using the indirect tensile test. In addition, the variation in the tensile and elastic properties which can be expected along the design length of a roadway was estimated. /FHWA/
Patent•
21 May 1974
TL;DR: In this article, a machine for subjecting a test piece of superplastic material to a tensile test using a mobile member entraining one end of the test-piece and exerting traction on the test piece is described.
Abstract: The apparatus includes a machine for subjecting a test-piece of superplastic material to a tensile test using a mobile member entraining one end of the test-piece and exerting traction on the test-piece. The mobile member is subjected to successive displacements whose speed and duration are controlled. The force applied to the test-piece and its length are measured as a function of time.
Patent•
21 May 1974
TL;DR: In this paper, a machine for subjecting a test piece to a tensile test using a mobile member entraining one end of the test piece and exerting traction on the testpiece is described.
Abstract: The apparatus includes a machine for subjecting a test-piece to a tensile test using a mobile member entraining one end of the test-piece and exerting traction on the test-piece. The mobile member is subjected to controlled displacements. The force applied to the test-piece and its length are measured as a function of time.
TL;DR: In this article, the properties of a low carbon mild steel in monotonic tension loading were compared in the plain normalized and the carbo-nitrided slowly cooled conditions.
Abstract: The properties of a low carbon mild steel in monotonic tension loading were compared in the plain normalized and the carbo-nitrided slowly cooled conditions. The application of a carbo-nitriding process raised the yield strength of the steel to that of the nominal tensile strength in the uncarburized samples, and increased the nominal tensile strength to a value 45% above that of the plain normalized steel, whilst still retaining a good measure of ductility. The fractures for the plain samples were “cup and cone” type whilst those for the reinforced samples revealed “slant mode” fractures.
TL;DR: In this paper, the construction of an apparatus to measure the tensile strength of ceramic specimens in the form of thin-walled rings is described, and it has been used satisfactorily on sintered polycrystalline UO2 up to 500 degrees C with either putty or low softening point glass as the pressurizing medium.
Abstract: The construction of an apparatus to measure the tensile strength of ceramic specimens in the form of thin-walled rings is described. In its present form it has been used satisfactorily on sintered polycrystalline UO2 up to 500 degrees C with either putty or low softening point glass as the pressurizing medium. Since the major problem preventing use at higher temperature appears to be oxidation of the specimens, the equipment, even in its present form, could possibly be used at appreciably higher temperatures with less oxygen-sensitive materials.
28 Mar 1974
TL;DR: In this article, a tensile test and testing procedures were developed and used to evaluate the effects of lubricants, coatings and reeling conditions on glass fiber strength, and the results indicated that fiber failure always originated at surface imperfections and that the appropriate lubricants and coatings could preserve fiber strength by affording some degree of protection to the fiber surface.
Abstract: : A tensile test and testing procedures were developed and used to evaluate the effects of lubricants, coatings and reeling conditions on glass fiber strength. The results indicated that fiber failure always originated at surface imperfections and that the appropriate lubricants and coatings could preserve fiber strength by affording some degree of protection to the fiber surface. Fiber strength was also found to be a function of the reeling parameters. Attempts to predict the strength of long lengths of fiber from short gage length data were inconclusive. (Author)
TL;DR: In this article, a set of tensile test pieces were cast by four selected sprueing techniques and studied for density and tensile properties, including horizontal twin feed and vertical twin feed.
Abstract: Tensile test pieces were cast by four selected sprueing techniques and studied for density and tensile properties. One of the sprueing systems referred to as horizontal twin feed produced the most consistent and the highest values for mechanical properties. This same series exhibited the lowest percentage elongation and the highest density.