5.1 There are many underground structures that are constructed for permanent or long-term use. Often, these structures are subjected to a relatively constant load. Creep tests provide quantitative parameters for stability analysis of these structures.5.2 The deformation and strength properties of rock cores measured in the laboratory usually do not accurately reflect large-scale in situ properties, because the latter are strongly influenced by joints, faults, inhomogeneities, weakness planes, and other factors. Therefore, laboratory test results of intact specimens shall be utilized with proper judgment in engineering applications.NOTE 1: The statements on precision and bias contained in this test method; the precision of this test method is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing. Users of this test method are cautioned that compliance with Practice D3740 does not in itself assure reliable testing. Reliable testing depends on many factors; Practice D3740 provides a means of evaluating some of these factors.1.1 These test methods cover the creep behavior of intact weak and hard rock core in fixed states of stress at ambient (room) or elevated temperatures. For creep behavior at lower temperatures refer to Test Method D5520. The methods specify the apparatus, instrumentation, and procedures necessary to determine the strain as a function of time under sustained load at constant temperature and when applicable, constant humidity.1.1.1 Hard rocks are considered those with a maximum axial strain at failure of less than 2 %. Weak rocks include such materials as salt, potash, shale, and weathered rock, which often exhibit very large strain at failure.1.2 This standard consists of three methods that cover the creep capacity of core specimens.1.2.1 Method A—Creep of Hard Rock Core Specimens in Uniaxial Compression at Ambient or Elevated Temperature.1.2.2 Method B—Creep of Weak Rock Core Specimens in Uniaxial Compression at Ambient or Elevated Temperature.1.2.3 Method C—Creep of Rock Core Specimens in Triaxial Compression at Ambient or Elevated Temperature.1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.4 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to commensurate with these considerations. It is beyond the scope of these test methods to consider significant digits used in analysis methods for engineering design.1.5 Units—The values stated in SI units are to be regarded as the standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Section 7.

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AbstractThese practices cover the visual stress-grading principles applicable to structural wood members of nonrectangular shape, as typically used in log buildings. The grading provisions presented herein are not intended to establish grades for purchase, but rather to show how stress-grading principles are applied to members used in log buildings.1.1 These practices cover the visual stress-grading principles applicable to structural wood members of nonrectangular shape, as typically used in log buildings. These practices are meant to supplement the ASTM standards listed in Section 2, which cover stress-grading of sawn lumber and round timbers. Pieces covered by these practices may also be used in building types other than log buildings.1.2 The grading provisions used as illustrations herein are not intended to establish grades for purchase, but rather to show how stress-grading principles are applied to members used in log buildings. Detailed grading rules for commercial stress grades which serve as purchase specifications are established and published by agencies that formulate and maintain such rules and operate inspection facilities covering the various species.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 Flat jack tests are useful to assess rock mass deformability and stresses in the design stages of projects as well as for issues with existing projects; for example, stresses around an underground opening. The in situ stress values can be used as an important parameter for interpretation and validation of test results and analytical models.5.2 This test method has been successfully used for other applications such as concrete dams and masonry structures. This test method is similar to the techniques and equipment used in C1196 and C1197. However, this standard is written more for rock and where irregular surfaces may be involved and both in situ stress and deformability are obtained in one test.NOTE 1: Notwithstanding the statements on precision and bias contained in this test method; the precision of this test method is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing. Users of this test method are cautioned that compliance with Practice D3740 does not in itself assure reliable testing. Reliable testing depends on many factors; Practice D3740 provides a means of evaluating some of those factors.1.1 The flat jack test measures the natural or altered in situ stress at a rock surface either for a surface outcrop or an underground excavation surface. The modulus of deformation and the long-term deformational properties (creep) may also be evaluated for the applied stress range, however long-term creep is not covered by this method.1.2 This method covers square flat jacks that are placed in a rock slot and if required encapsulated in the slot.1.3 Deformation readings are taken at the surface, but this standard does not exclude deformation readings being taken below the surface, such as using a flat jack which is set up to obtain displacement data internally.1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.1.5 Limitation—The flat jack test measures the average stress normal to the surface of the test chamber, underground excavation, or outcrop. In situ stress levels must be determined by theoretical interpretations of these data.1.6 Assumptions and Factors Influencing the Data: 1.6.1 The stress relief is assumed to be an elastic, reversible process. In nonhomogeneous or highly fractured materials, this may not be completely true.1.6.2 The equations assume that the rock mass is isotropic and homogeneous. Anisotropic effects may be estimated by testing in different orientations.1.6.3 The flat jack is assumed to be 100 % efficient. The design and size requirements of 7.1 were determined to satisfy this requirement to within a few percent.1.6.4 The jack is assumed to be aligned with the principal stresses on the surface being measured. Shear stresses are not canceled by jack pressure. Orientating the tests in three directions in each plane tested prevents the misalignment from being excessive for at least one of the tests.1.7 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. Add if appropriate, “Reporting of test results in units other than inch-pounds shall not be regarded as nonconformance with this standard.”1.7.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The slug unit is not given unless dynamic (F=ma) calculations are involved. For standards involving the determination of mass or the use of density and unit weight, include the following numbered paragraph.1.7.2 The slug unit of mass is typically not used in commercial practice; that is, density, balances, and so on. Therefore, the standard unit for mass in this standard is either kilogram (kg) or gram (g) or both. Also, the equivalent inch-pound unit (slug) is not given/presented in parentheses.1.7.3 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This practice implicitly combines two separate systems of units; the absolute and the gravitational systems. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit for mass. However, the use of balances or scales recording pounds of mass (lbm) or recording density in lbm/ft3 shall not be regarded as nonconformance with this standard.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 This test method compares closures for ESCR. Suitable variables are: closure materials, closure designs, processes, applied torque, and stress-crack agents.5.2 Results can be used for estimating shelf life of closures in terms of ESCR. This requires that the user has calibrated failure time in this test to failure time in the field for actual packaging systems.1.1 This test method determines the susceptibility of threaded plastic closures to failure due to environmental stress cracking (ESC).1.2 In use, threaded plastic closures can contact agents that appreciably reduce the stress at which cracks form. Examples of such agents are: soaps, detergents, oils, and liquid bleaches.1.3 Major factors that influence environmental stress crack resistance (ESCR) of threaded plastic closures include the closure material(s), closure design, molded-in stress, and applied stress.1.4 This procedure can be applied to all closures, but is particularly applicable to closures made from plastics based on polypropylene (PP) or polystyrene (PS).1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8 and 6.2.NOTE 1: There is no known ISO equivalent to this standard.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 The intent of this test method is to determine the time dependence of modulus in building joint sealants using two loading-unloading cycles to identify and mitigate any Mullins effect, and followed by a stress relaxation procedure to determine the time dependent modulus.5.2 This test method has found applications in screening the performance of building joint sealants since the modulus is one indicator of the ability of elastomeric building sealant to withstand environmental induced movements.1.1 This test method covers a procedure for measuring the time dependence of modulus in elastomeric joint sealants in a test specimen configuration described in Test Method C719. These sealant materials are typified by highly filled rubber materials. Any Mullins effect is first assessed and mitigated in two loading-unloading cycles. Time dependence of modulus in materials is then determined using a stress relaxation procedure.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 Generation of combustible gases is used to determine the condition of oil-filled electrical apparatus. Many years of empirical evidence has yielded guidelines such as those given in IEEE C57.104, IEC 60599 and IEC 61464. Industry experience has shown that electric and thermal faults in oil-filled electrical apparatus are the usual sources that generate gases. Experience has shown that some of the gases could form in the oil due to thermal stress or as a result of contamination, without any other influences.5.2 Some transformer oils subjected to thermal stress and oils that contain certain types of contamination may produce specific gases at lower temperatures than normally expected for their generation and hence, falsely indicate abnormal operation of the electrical apparatus. Some new oils have produced large amounts of gases, especially hydrogen, without the influence of other electrical apparatus materials or electrical stresses. This renders interpretation of the dissolved gas analysis more complicated.5.3 Heating for 164 h has been found to be sufficient to reach a stable and characteristic gassing pattern.5.4 This method uses both dry air and dry nitrogen as the sparging gas. This is to reflect either an electrical apparatus preservation system that allows oxygen to contact the oil or one that is sealed from the outside atmosphere. Oils sparged with air generally produce much more hydrogen as a percentage of the total combustible gas content as compared to oils sparged with nitrogen as these produce more hydrocarbons in relation to hydrogen.1.1 This test method describes the procedures to determine the gassing characteristics due to thermal stress at 120°C of insulating liquids specifically and without the influence of other electrical apparatus materials or electrical stresses. This test method was primarily designed for insulating mineral oil. It can be applied to other insulating liquids in which dissolved gas-in-oil analysis (Test Method D3612) is commonly performed.1.2 This test method is particularly suited for detection of the phenomenon sometimes known as “stray gassing” and is also referred to in CIGRE TF11 B39.1.3 This test method is performed on transformer insulating liquids to determine the propensity of the oil to produce certain gases such as hydrogen and hydrocarbons at low temperatures.1.4 This test method details two procedures:1.5 Method A describes the procedure for determining the gassing characteristics of insulating liquids, at 120°C for 164 h.1.6 Method B describes the procedure for processing the insulating liquid through an attapulgite clay column to remove organic contaminants and other reactive groups that may influence the gassing behavior of an insulating liquid, which is suspected of being contaminated. This procedure applies to both new and used insulating liquids.1.7 The values stated in SI units are to be regarded as standard. English units are used when there is no metric equivalent.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 The yield stress of a material is a measure of the amount of force required to initiate movement of that material in a pipe, through a pump, or from nozzle. The yield stress also characterizes the ability of the material to maintain particles in suspension. Along with viscosity measurements, yield stress measurements have been useful in establishing root causes of flow problems such as excessive orange peel and sagging and in explaining resistance to such problems. After a coating has been applied, flow and leveling tends to be inversely related to yield stress and sag resistance tends to be directly related to yield stress. The ability of an automotive basecoat to keep aluminum and/or mica flakes oriented has been related to yield stress (direct relationship).1.1 These test methods cover three approaches for determining yield stress values of paints, inks and related liquid materials using rotational viscometers. The first method uses a rotational viscometer with coaxial cylinder, cone/plate, or plate/plate geometry. The second method uses a rheometer operating in controlled stress mode with similar geometries. The third method uses a viscometer with a vane spindle.1.2 A non-rotational technique, the falling needle viscometer (FNV), also can be used to measure yield stress values in paints, inks and related materials. See Test Methods D5478, Test Method D, Yield Stress Determination for details.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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定价： 515元 加购物车

定价： 590元 加购物车

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定价： 590元 加购物车

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This specification covers a limit for thermal residual stress in reusable annealed glass laboratory apparatus as determined by prescribed photoelastic measurement procedures. This specification recognizes that photoelastic measurements are proportional to the difference of the principal stresses. The stress limit shall be measured and calculated to meet the specified requirements.1.1 This specification covers a limit for thermal residual stress in reusable annealed glass laboratory apparatus as determined by prescribed photoelastic measurement procedures.1.2 In broad classification, the laboratory glassware items covered by this specification, but not limited to, are:beakers Imhoff conesbottles, aspirator impingersbottles, dropping jars, batterybottles, gas washing jars, bellbottles, infusion jars, chromatographybottles, milk test jars, cylindricalbottles, reagent joints, ball and socket or standard taperbottles, weighing manometersbulbs, absorption percolatorsbulbs, leveling pycnometersbulbs, sampling stopcocksburets tubes, centrifugecondensers tubes, chromatographycrystallizing dishes tubes, color comparison (turbidity)culture dishes tubes, combustion (ignition)custom apparatus tubes, connecting and adaptercylinders, graduated tubes, digestion and plain tubes, dryingdesiccators tubes, fermentationextraction tubes tubes, thistle (spray traps)flasks vapor trapsfritted ware viscometersfunnels watch glassesgenerators, Kipp  grinder, tissue  1.3 This specification recognizes that photoelastic measurements are proportional to the difference of the principal stresses. The limit imposed represents a safety factor to cover a situation in which one of the principal stresses may be larger than the apparent stress.1.4 This specification applies only to annealed glassware that is intended for sale as such. It excludes glassware that has been thermally tempered, ion-exchanged, or laminated with glass layers of differing expansion. The intent of this specification is to limit the residual stresses for safe consumer use in annealed glass, as it leaves the manufacturer.1.5 Stresses introduced by thermal expansion differences within the glassware are covered by this specification. Graded and glass-to-metal seals are excluded.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 加购物车