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4.1 The service life of many structural ceramic components is often limited by the subcritical growth of cracks. This test method provides an approach for appraising the relative slow crack growth susceptibility of ceramic materials under specified environments at ambient temperature. Furthermore, this test method may establish the influences of processing variables and composition on slow crack growth as well as on strength behavior of newly developed or existing materials, thus allowing tailoring and optimizing material processing for further modification. In summary, this test method may be used for material development, quality control, characterization, design code or model verification, and limited design data generation purposes.NOTE 4: Data generated by this test method do not necessarily correspond to crack velocities that may be encountered in service conditions. The use of data generated by this test method for design purposes, depending on the range and magnitude of applied stresses used, may entail extrapolation and uncertainty.4.2 This test method is related to Test Method C1368 (“constant stress-rate flexural testing”), however, C1368 uses constant stress rates to determine corresponding flexural strengths whereas this test method employs constant stress to determine corresponding times to failure. In general, the data generated by this test method may be more representative of actual service conditions as compared with those by constant stress-rate testing. However, in terms of test time, constant stress testing is inherently and significantly more time consuming than constant stress rate testing.4.3 The flexural stress computation in this test method is based on simple elastic beam theory, with the assumptions that the material is isotropic and homogeneous, the moduli of elasticity in tension and compression are identical, and the material is linearly elastic. The grain size should be no greater than one-fiftieth (1/50 ) of the beam depth as measured by the mean linear intercept method (Test Methods E112). In cases where the material grain size is bimodal or the grain size distribution is wide, the limit should apply to the larger grains.4.4 The test specimen sizes and test fixtures have been selected in accordance with Test Methods C1161 and C1368, which provides a balance between practical configurations and resulting errors, as discussed in Ref (4, 5).4.5 The data are evaluated by regression of log applied stress versus log time to failure to the experimental data. The recommendation is to determine the slow crack growth parameters by applying the power law crack velocity function. For derivation of this, and for alternative crack velocity functions, see Appendix X1.NOTE 5: A variety of crack velocity functions exist in the literature. A comparison of the functions for the prediction of long-term static fatigue data from short-term dynamic fatigue data (6) indicates that the exponential forms better predict the data than the power-law form. Further, the exponential form has a theoretical basis (7-10), however, the power law form is simpler mathematically. Both have been shown to fit short-term test data well.4.6 The approach used in this method assumes that the material displays no rising R-curve behavior, that is, no increasing fracture resistance (or crack-extension resistance) with increasing crack length. The existence of such behavior cannot be determined from this test method. The analysis further assumes that the same flaw type controls all times-to-failure.4.7 Slow crack growth behavior of ceramic materials can vary as a function of mechanical, material, thermal, and environmental variables. Therefore, it is essential that test results accurately reflect the effects of specific variables under study. Only then can data be compared from one investigation to another on a valid basis, or serve as a valid basis for characterizing materials and assessing structural behavior.4.8 Like strength, time to failure of advanced ceramics subjected to slow crack growth is probabilistic in nature. Therefore, slow crack growth that is determined from times to failure under given constant applied stresses is also a probabilistic phenomenon. The scatter in time to failure in constant stress testing is much greater than the scatter in strength in constant stress-rate (or any strength) testing (1, 11-13), see Appendix X2. Hence, a proper range and number of constant applied stresses, in conjunction with an appropriate number of test specimens, are required for statistical reproducibility and reliable design data generation (1-3). This standard provides guidance in this regard.4.9 The time to failure of a ceramic material for a given test specimen and test fixture configuration is dependent on its inherent resistance to fracture, the presence of flaws, applied stress, and environmental effects. Fractographic analysis to verify the failure mechanisms has proven to be a valuable tool in the analysis of SCG data to verify that the same flaw type is dominant over the entire test range Ref (14, 15), and it is to be used in this standard (refer to Practice C1322).1.1 This standard test method covers the determination of slow crack growth (SCG) parameters of advanced ceramics by using constant stress flexural testing in which time to failure of flexure test specimens is determined in four-point flexure as a function of constant applied stress in a given environment at ambient temperature. In addition, test specimen fabrication methods, test stress levels, data collection and analysis, and reporting procedures are addressed. The decrease in time to failure with increasing applied stress in a specified environment is the basis of this test method that enables the evaluation of slow crack growth parameters of a material. The preferred analysis in the present method is based on a power law relationship between crack velocity and applied stress intensity; alternative analysis approaches are also discussed for situations where the power law relationship is not applicable.NOTE 1: The test method in this standard is frequently referred to as “static fatigue” or stress-rupture testing (1-3)2 in which the term “fatigue” is used interchangeably with the term “slow crack growth.” To avoid possible confusion with the “fatigue” phenomenon of a material that occurs exclusively under cyclic loading, as defined in Terminology E1823, this test method uses the term “constant stress testing” rather than “static fatigue” testing.1.2 This test method applies primarily to monolithic advanced ceramics that are macroscopically homogeneous and isotropic. This test method may also be applied to certain whisker- or particle-reinforced ceramics as well as certain discontinuous fiber-reinforced composite ceramics that exhibit macroscopically homogeneous behavior. Generally, continuous fiber ceramic composites do not exhibit macroscopically isotropic, homogeneous, continuous behavior, and the application of this test method to these materials is not recommended.1.3 This test method is intended for use with various test environments such as air, other gaseous environments, and liquids.1.4 The values stated in SI units are to be regarded as the standard and in accordance with IEEE/ASTM SI 10 Standard.1.5 This test method may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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4.1 The service life of many structural ceramic components is often limited by the subcritical growth of cracks over time, under stress at a defined temperature, and in a defined chemical environment (Refs 1-3). When one or more cracks grow to a critical size, brittle catastrophic failure may occur in the component. Slow crack growth in ceramics is commonly accelerated at elevated temperatures. This test method provides a procedure for measuring the long term load-carrying ability and appraising the relative slow crack growth susceptibility of ceramic materials at elevated temperatures as a function of time, temperature, and environment. This test method is based on Test Method C1576 with the addition of provisions for elevated temperature testing.4.2 This test method is also used to determine the influences of processing variables and composition on slow crack growth at elevated temperatures, as well as on strength behavior of newly developed or existing materials, thus allowing tailoring and optimizing material processing for further modification.4.3 This test method may be used for material development, quality control, characterization, design code or model verification, time-to-failure, and limited design data generation purposes.NOTE 2: Data generated by this test method do not necessarily correspond to crack velocities that may be encountered in service conditions. The use of data generated by this test method for design purposes, depending on the range and magnitude of applied stresses used, may entail extrapolation and uncertainty.4.4 This test method and Test Method C1576 are similar and related to Test Methods C1368 and C1465; however, C1368 and C1465 use constant stress-rates (linearly increasing stress over time) to determine corresponding flexural strengths, whereas this test method and C1576 employ a constant stress (fixed stress levels over time) to determine corresponding times-to-failure. In general, the data generated by this test method may be more representative of actual service conditions as compared with data from constant stress-rate testing. However, in terms of test time, constant stress testing is inherently and significantly more time consuming than constant stress-rate testing.4.5 The flexural stress computation in this test method is based on simple elastic beam theory, with the following assumptions: the material is isotropic and homogeneous; the moduli of elasticity in tension and compression are identical; and the material is linearly elastic. These assumptions are based on small grain size in the ceramic specimens. The grain size should be no greater than 1/50 of the beam depth as measured by the mean linear intercept method (E112). In cases where the material grain size is bimodal or the grain size distribution is wide, the limit should apply to the larger grains.4.6 The test specimen sizes and test fixtures have been selected in accordance with Test Method C1211 which provides a balance between practical configurations and resulting errors, as discussed in Refs 4 and 5. Test Method C1211 also specifies fixture material requirements for elevated test temperature stability and functionality.4.7 The SCG data are evaluated by regression of log applied-stress vs. log time-to-failure to the experimental data. The recommendation is to determine the slow crack growth parameters by applying the power law crack velocity function. For derivation of this, and for alternative crack velocity functions, see Appendix X1.NOTE 3: A variety of crack velocity functions exist in the literature. A comparison of the functions for the prediction of long-term constant stress (static fatigue) data from short-term constant stress rate (dynamic fatigue) data (Ref 6) indicates that the exponential forms better predict the data than the power-law form. Further, the exponential form has a theoretical basis (Refs 7-10); however, the power law form is simpler mathematically. Both forms have been shown to fit short-term test data well.4.8 The approach used in this test method assumes that the ceramic material displays no rising R-curve behavior, that is, no increasing fracture resistance (or crack-extension resistance) with increasing crack length for a given test temperature. The existence of such R-curve behavior cannot be determined from this test method. The analysis further assumes that the same flaw type controls all times-to-failure for a given test temperature.4.9 Slow crack growth behavior of ceramic materials can vary as a function of material properties, thermal conditions, and environmental variables. Therefore, it is essential that test results accurately reflect the effects of the specific variables under study. Only then can data be compared from one investigation to another on a valid basis, or serve as a valid basis for characterizing materials and assessing structural behavior.4.10 Like mechanical strength, the SCG time-to-failure of advanced ceramics is probabilistic in nature. Therefore, slow crack growth that is determined from times-to-failure under given constant applied stresses is also a probabilistic phenomenon. The scatter in time-to-failure in constant stress testing is much greater than the scatter in strength in constant stress-rate (or any strength) testing (Refs 1, 11-13; see Appendix X2). Hence, a proper range and number of constant applied stress levels, in conjunction with an appropriate number of test specimens, are required for statistical reproducibility and reliable design data generation (Ref 1-3). This test method provides guidance in this regard.4.11 The time-to-failure of a ceramic material for a given test specimen and test fixture configuration is dependent on the ceramic material’s inherent resistance to fracture, the presence of flaws, the applied stress, and the temperature and environmental effects. Fractographic analysis to verify the failure mechanisms has proven to be a valuable tool in the analysis of SCG data to verify that the same flaw type is dominant over the entire test range (Refs 14, 15), and fractography is recommended in this test method (refer to Practice C1322).1.1 This test method covers the determination of the slow crack growth (SCG) parameters of advanced ceramics in a given test environment at elevated temperatures in which the time-to-failure of four-point-1/4 point flexural test specimens (see Fig. 1) is determined as a function of different levels of constant applied stress. This SCG constant stress test procedure is also called a slow crack growth (SCG) stress rupture test. The test method addresses the test equipment, test specimen fabrication, test stress levels and experimental procedures, data collection and analysis, and reporting requirements.1.2 In this test method the decrease in time-to-failure with increasing levels of applied stress in specified test conditions and temperatures is measured and used to analyze the slow crack growth parameters of the ceramic. The preferred analysis method is based on a power law relationship between crack velocity and applied stress intensity; alternative analysis approaches are also discussed for situations where the power law relationship is not applicable.NOTE 1: This test method is historically referred to in earlier technical literature as static fatigue testing (Refs 1-3)2 in which the term fatigue is used interchangeably with the term slow crack growth. To avoid possible confusion with the fatigue phenomenon of a material that occurs exclusively under cyclic stress loading, as defined in E1823, this test method uses the term constant stress testing rather than static fatigue testing.1.3 This test method uses a 4-point-1/4 point flexural test mode and applies primarily to monolithic advanced ceramics that are macroscopically homogeneous and isotropic. This test method may also be applied to certain whisker- or particle-reinforced ceramics as well as certain discontinuous fiber-reinforced composite ceramics that exhibit macroscopically homogeneous behavior. Generally, continuous fiber ceramic composites do not exhibit macroscopically isotropic, homogeneous, elastic continuous behavior, and the application of this test method to these materials is not recommended.1.4 This test method is intended for use at elevated temperatures with various test environments such as air, vacuum, inert gas, and steam. This test method is similar to Test Method C1576 with the addition of provisions for testing at elevated temperatures to establish the effects of those temperatures on slow crack growth. The elevated temperature testing provisions are derived from Test Methods C1211 and C1465.1.5 Creep deformation at elevated temperatures can occur in some ceramics as a competitive mechanism with slow crack growth. Those creep effects may interact and interfere with the slow crack growth effects (see 5.5). This test method is intended to be used primarily for ceramic test specimens with negligible creep. This test method imposes specific upper-bound limits on measured maximum creep strain at fracture or run-out (no more than 0.1 %, in accordance with 5.5).1.6 The values stated in SI units are to be regarded as the standard and in accordance with IEEE/ASTM SI 10.1.7 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 determine the applicability of regulatory limitations prior to use.

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4.1 This test method provides a guide for evaluating whether a specific solvent, chemical, or compound is detrimental to a transparent plastic as a result of a manufacturing process, a fabrication operation, or the operational environment. All transparent plastics are susceptible to crazing, though in widely varying degree and from a variety of causes. This test method is intended to allow establishment of the crazing stress when the simultaneous action of both load and a material that will cause crazing is applied, producing non-reversible damage that limits the usage of that transparent plastic in a specific application.1.1 This test method covers the determination of the critical crazing stress for a transparent plastic material when exposed to a specific solvent, chemical, or compound at a specific temperature.1.2 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.1.3 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： 590元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 590元 加购物车

定价： 590元 加购物车

5.1 This test method is useful for determining the variability in material and the influence of parameters affecting the stress-strain properties of rubber vulcanizates, for example, temperature, relative humidity, preconditioning of rubber, and so forth. This test method is particularly useful for the evaluation of compounding materials used for reference purposes.1.1 This test method covers determination of the elongation of soft vulcanized rubber compounds under a specified stress.1.2 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.1.3 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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4.1 This guide is intended to describe heat management program elements that foundries use to prevent or manage heat strain and heat-related illness. Specifically, the guide:4.1.1 Provides an objective framework for recognizing heat stress and heat strain, and4.1.2 Facilitates use of best practices to manage heat exposures to minimize heat strain and prevent heat-related illness.1.1 This guide is intended to establish best practices for recognizing and managing occupational heat stress and heat strain in foundry environments.1.2 Objectives of the foundry heat stress and heat strain management guide are as follows:1.2.1 Provide an objective framework for recognizing heat stress and heat strain, and1.2.2 Facilitate use of best practices to manage heat exposures to minimize heat strain and prevent heat-related illness.1.3 In this guide, procedures necessary to manage heat stress and heat strain in foundries are described.1.4 Key elements of this guide include definitions of heat stress and heat strain, plus techniques for recognizing, communicating, managing, and controlling heat stress and heat strain to prevent heat-related illnesses.1.5 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.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.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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定价： 590元 加购物车

3.1 Stress-optical coefficients are used in the determination of stress in glass. They are particularly useful in determining the magnitude of thermal residual stresses for annealing or pre-stressing (tempering) glass. As such, they can be important in specification acceptance.1.1 This test method covers procedures for determining the stress-optical coefficient of glass, which is used in photoelastic analyses. In Procedure A the optical retardation is determined for a glass fiber subjected to uniaxial tension. In Procedure B the optical retardation is determined for a beam of glass of rectangular cross section when subjected to four-point bending. In Procedure C, the optical retardation is measured for a beam of glass of rectangular cross-section when subjected to uniaxial compression.1.2 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.1.3 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： 975元 / 折扣价： 829 元 加购物车

4.1 The performance of glass products may be affected by presence of residual stresses due to process, differential thermal expansion between fused components, and by inclusions. This test method provides means of quantitative evaluation of stresses.1.1 This test method covers the analysis of stress in glass by means of a polarimeter based on the principles developed by Jessop and Friedel (1, 2).2 Stress is evaluated as a function of optical retardation, that is expressed as the angle of rotation of an analyzing polarizer that causes extinction in the glass.1.2 There is no known ISO equivalent to this 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.

定价： 590元 加购物车