定价： 927元 加购物车

定价： 646元 加购物车

定价： 571元 加购物车

4.1 Fatigue test results may be significantly influenced by the properties and history of the parent material, the operations performed during the preparation of the fatigue specimens, and the testing machine and test procedures used during the generation of the data. The presentation of fatigue test results should include citation of basic information on the material, specimens, and testing to increase the utility of the results and to reduce to a minimum the possibility of misinterpretation or improper application of those results.1.1 This practice covers the desirable and minimum information to be communicated between the originator and the user of data derived from constant-force amplitude axial, bending, or torsion fatigue tests of metallic materials tested in air and at room temperature.NOTE 1: Practice E466, although not directly referenced in the text, is considered important enough to be listed in this standard.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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

1.1 These tables define the solar constant and zero air mass solar spectral irradiance for use in thermal analysis, thermal balance testing, and other tests of spacecraft and spacecraft components and materials. Typical applications include the calculation of solar absorptance from spectral reflectance data, the specification of solar UV exposure of materials during simulated space radiation testing, and the rating of photovoltaic cells deployed in space.1.2 These tables are based upon data from experimental measurements made mostly from spacecraft, with minor contributions from observations made on high-altitude aircraft, or from the earth's surface.1.3 These tables are representative of periods when the sun’s activity is average or moderate. The sun’s activity tends to modify its spectrum almost exclusively in the UV and extreme UV spectral regions (below 0.1 µm).1.4 Units—The values stated in SI units are to be regarded as standard. Other units of measurement are included for information purposes only.1.5 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.1.6 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： 843元 加购物车

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.

定价： 590元 加购物车

定价： 515元 加购物车

4.1 The viscosity-gravity constant (VGC) is a useful function for the approximate characterization of the viscous fractions of petroleum.2 It is relatively insensitive to molecular weight and is related to a fluids composition as expressed in terms of certain structural elements. Values of VGC near 0.800 indicate samples of paraffinic character, while values close to 1.00 indicate a preponderance of aromatic structures. Like other indicators of hydrocarbon composition, the VGC should not be indiscriminately applied to residual oils, asphaltic materials, or samples containing appreciable quantities of nonhydrocarbons.1.1 This test method covers the calculation of the viscosity-gravity constant (VGC) of petroleum oils2 having viscosities in excess of 5.5 mm2/s at 40 °C (104 °F) and in excess of 0.8 mm2/s at 100 °C (212 °F).1.2 Annex A1 describes a method for calculating the VGC from Saybolt (SUS) viscosity and relative density.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3.1 The SI unit of kinematic viscosity is mm2/s.1.3.2 Exception—Fahrenheit temperature units are used in this practice because they are accepted by industry for the type of legacy conversions described in this practice.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.

定价： 515元 加购物车

4.1 These test methods are normally used for the following purposes:4.1.1 To evaluate materials and constructions for a specific type of container,4.1.2 To compare performance of different types of containers,4.1.3 To determine adequacy of protection for a specific product or application, and4.1.4 To maintain quality control.1.1 These test methods cover the determination of water vapor transmission rates for bulk shipping containers, as follows:1.1.1 Method A, for Reclosable Containers, and1.1.2 Method B, for Containers Not Designed for Reclosing.1.2 Within each procedure details are given for the constant and cycle methods of test atmosphere.1.3 The test may be applied to the container as packed, or after one or more performance tests such as drum (Method D782), vibration (Methods D999), drop (Test Method D5276), impact resistance (Test Methods D880, D4003, and D5277), or performance tests (Practice D4169), as required.1.4 For small shipping containers requiring greater accuracy in weighing, the water vapor transmission may be determined in accordance with Test Method D895 or Test Method D1251.1.5 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.1.6 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.

定价： 515元 加购物车

5.1 Constant force thermal cycling tests determine the effect of stress on the transformation temperatures, recovered strain and residual strain of a shape memory alloy. The tests may be for one thermal cycle. A standard test method for force controlled repeated thermal cycling of shape memory alloys is currently under development.5.2 Measurement of the specimen's thermomechanical behavior closely parallels many shape memory applications and provides a result that is applicable to the function of the material.5.3 This test method may be used for, but is not limited to, wire, round tube, or strip samples. Thus it is able to provide an assessment of the product in its semi-finished form.5.4 This test method provides a simple method for determining transformation temperatures by heating and cooling specimens through their full thermal transformation under force.5.5 This test method can be used on trained and processed material in a semi-finished form to measure Two Way Shape Memory Effect by comparing the strain in the austenite state and martensite states with no minimal applied stress. The force is set to a minimum value not to exceed a corresponding stress of 7 MPa (in accordance Test Method F2516).5.6 This test method is useful for quality control, specification acceptance, and research.5.7 Transformation temperatures derived from this test method may not agree with those obtained by other test methods due to the effects of strain and stress on the transformation.5.8 Components such as springs or other semi-finished parts can be tested using this method as agreed upon by the customer and supplier. Units of stress and strain can be replaced with force and displacement.1.1 This test method defines procedures for thermomechanical cycling of shape memory alloy (SMA) material and components under constant force. This method characterizes the transformation properties such as transformation temperatures, actuation strain and residual strain, when a SMA is thermally cycled through the phase transformation under a constant applied force. This test is done to provide data for the selection of SMA materials, quality control, design allowables and actuator design.1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in 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

定价： 571元 加购物车

定价： 927元 加购物车

5.1 Permittivity—Insulating materials are used in general in two distinct ways, (1) to support and insulate components of an electrical network from each other and from ground, and (2) to function as the dielectric of a capacitor. For the first use, it is generally desirable to have the capacitance of the support as small as possible, consistent with acceptable mechanical, chemical, and heat-resisting properties. A low value of permittivity is thus desirable. For the second use, it is desirable to have a high value of permittivity, so that the capacitor is able to be physically as small as possible. Intermediate values of permittivity are sometimes used for grading stresses at the edge or end of a conductor to minimize ac corona. Factors affecting permittivity are discussed in Appendix X3.5.2 AC Loss—For both cases (as electrical insulation and as capacitor dielectric) the ac loss generally needs to be small, both in order to reduce the heating of the material and to minimize its effect on the rest of the network. In high frequency applications, a low value of loss index is particularly desirable, since for a given value of loss index, the dielectric loss increases directly with frequency. In certain dielectric configurations such as are used in terminating bushings and cables for test, an increased loss, usually obtained from increased conductivity, is sometimes introduced to control the voltage gradient. In comparisons of materials having approximately the same permittivity or in the use of any material under such conditions that its permittivity remains essentially constant, it is potentially useful to consider also dissipation factor, power factor, phase angle, or loss angle. Factors affecting ac loss are discussed in Appendix X3.5.3 Correlation—When adequate correlating data are available, dissipation factor or power factor are useful to indicate the characteristics of a material in other respects such as dielectric breakdown, moisture content, degree of cure, and deterioration from any cause. However, it is possible that deterioration due to thermal aging will not affect dissipation factor unless the material is subsequently exposed to moisture. While the initial value of dissipation factor is important, the change in dissipation factor with aging is often much more significant.5.4 Capacitance is the ratio of a quantity, q, of electricity to a potential difference, V. A capacitance value is always positive. The units are farads when the charge is expressed in coulombs and the potential in volts:5.5 Dissipation factor ((D), (loss tangent), (tan δ)) is the ratio of the loss index (κ") to the relative permittivity (κ′) which is equal to the tangent of its loss angle (δ) or the cotangent of its phase angle (θ) (see Fig. 1 and Fig. 2).The reciprocal of the dissipation factor is the quality factor, Q, sometimes called the storage factor. The dissipation factor, D, of the capacitor is the same for both the series and parallel representations as follows:The relationships between series and parallel components are as follows:5.5.2 Series Representation—While the parallel representation of an insulating material having a dielectric loss (Fig. 3) is usually the proper representation, it is always possible and occasionally desirable to represent a capacitor at a single frequency by a capacitance, Cs, in series with a resistance, Rs (Fig. 4 and Fig. 2).FIG. 3 Parallel CircuitFIG. 4 Series Circuit5.6 Loss angle ((phase defect angle), (δ)) is the angle whose tangent is the dissipation factor or arctan κ"/κ′ or whose cotangent is the phase angle.5.6.1 The relation of phase angle and loss angle is shown in Fig. 1 and Fig. 2. Loss angle is sometimes called the phase defect angle.5.7 Loss index (κ" (εr") is the magnitude of the imaginary part of the relative complex permittivity; it is the product of the relative permittivity and dissipation factor.5.7.1 The loss index is expressed as:.When the power loss is in watts, the applied voltage is in volts per centimeter, the frequency is in hertz, the volume is the cubic centimeters to which the voltage is applied, the constant has the value of 5.556 × 10−13.NOTE 2: Loss index is the term agreed upon internationally. In the United States, κ" was formerly called the loss factor.5.8 Phase angle (θ) is the angle whose cotangent is the dissipation factor, arccot κ"/κ′ and is also the angular difference in the phase between the sinusoidal alternating voltage applied to a dielectric and the component of the resulting current having the same frequency as the voltage.5.8.1 The relation of phase angle and loss angle is shown in Fig. 1 and Fig. 2. Loss angle is sometimes called the phase defect angle.5.9 Power factor (PF) is the ratio of the power in watts, W, dissipated in a material to the product of the effective sinusoidal voltage, V, and current, I, in volt-amperes.5.9.1 Power factor is expressed as the cosine of the phase angle θ (or the sine of the loss angle δ).When the dissipation factor is less than 0.1, the power factor differs from the dissipation factor by less than 0.5 %. Their exact relationship is found from the following:5.10 Relative permittivity ((relative dielectric constant) (SIC) κ′(εr)) is the real part of the relative complex permittivity. It is also the ratio of the equivalent parallel capacitance, Cp, of a given configuration of electrodes with a material as a dielectric to the capacitance, Cυ, of the same configuration of electrodes with vacuum (or air for most practical purposes) as the dielectric:NOTE 3: In common usage the word “relative” is frequently dropped.NOTE 4: Experimentally, vacuum must be replaced by the material at all points where it makes a significant change in capacitance. The equivalent circuit of the dielectric is assumed to consist of Cp, a capacitance in parallel with conductance. (See Fig. 3.)NOTE 5: Cx is taken to be Cp, the equivalent parallel capacitance as shown in Fig. 3.NOTE 6: The series capacitance is larger than the parallel capacitance by less than 1 % for a dissipation factor of 0.1, and by less than 0.1 % for a dissipation factor of 0.03. If a measuring circuit yields results in terms of series components, the parallel capacitance must be calculated from Eq 5 before the corrections and permittivity are calculated.NOTE 7: The permittivity of dry air at 23 °C and standard pressure at 101.3 kPa is 1.000536 (1).6 Its divergence from unity, κ′ − 1, is inversely proportional to absolute temperature and directly proportional to atmospheric pressure. The increase in permittivity when the space is saturated with water vapor at 23 °C is 0.00025 (2, 3), and varies approximately linearly with temperature expressed in degrees Celsius, from 10 °C to 27 °C. For partial saturation the increase is proportional to the relative humidity.1.1 These test methods cover the determination of relative permittivity, dissipation factor, loss index, power factor, phase angle, and loss angle of specimens of solid electrical insulating materials when the standards used are lumped impedances. The frequency range addressed extends from less than 1 Hz to several hundred megahertz.NOTE 1: In common usage, the word relative is frequently dropped.1.2 These test methods provide general information on a variety of electrodes, apparatus, and measurement techniques. A reader interested in issues associated with a specific material needs to consult ASTM standards or other documents directly applicable to the material to be tested.2,31.3 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. For specific hazard statements, see 10.2.1.1.4 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： 646元 加购物车

5.1 The data obtained by this test method are useful for establishing stress versus failure time relationships in a controlled environment from which the hydrostatic design basis for plastic pipe materials can be computed. (Refer to Test Method D2837 and Practice D2992.)5.2 In order to determine how plastics will perform as pipe, it is necessary to establish the stress-failure time relationships for pipe over 2 or more logarithmic decades of time (hours) in a controlled environment. Because of the nature of the test and specimens employed, no single line can adequately represent the data, and therefore the confidence limits should be established.NOTE 2: Some materials may exhibit a nonlinear relationship between log-stress and log-failure time, usually at short failure times. In such cases, the 105-hour stress value computed on the basis of short-term test data may be significantly different than the value obtained when a distribution of data points in accordance with Test Method D2837 is evaluated. However, these data may still be useful for quality control or other applications, provided correlation with long-term data has been established.5.3 The factors that affect creep and long-term strength behavior of plastic pipe are not completely known at this time. This procedure takes into account those factors that are known to have important influences and provides a tool for investigating others.5.4 Creep, or nonrecoverable deformation for pipe made of some plastics, is as important as actual leakage in deciding whether or not a pipe has failed. Specimens that exhibit localized ballooning, however, may lead to erroneous interpretation of the creep results unless a method of determining creep is established that precludes such a possibility. Circumferential measurements at two or three selected positions on a specimen may not be adequate.5.5 Great care must be used to ensure that specimens are representative of the pipe under evaluation. Departure from this assumption may introduce discrepancies as great as, if not greater than, those due to departure from details of procedure outlined in this test method.1.1 This test method covers the determination of the time-to-failure of both thermoplastic and reinforced thermosetting/resin pipe under constant internal pressure.1.2 This test method provides a method of characterizing plastics in the form of pipe under the conditions prescribed.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.

定价： 515元 加购物车

4.1 Constant torque thermal cycling tests determine the effect of shear stress on the transformation properties such as transformation temperatures, actuation shear strain and residual shear strain of a shape memory alloy. This test is done to provide data for the characterization selection of shape memory alloy materials, quality control, design allowables and actuator design (1-3).5 The tests should be used for one thermal cycle but may be used for repeated thermal cycles as agreed upon between supplier and customer.4.2 Measurement of the specimen's motion closely parallels many shape memory actuator applications and provides a result that is applicable to the function of the material.4.3 This test method may be used for cylindrical specimens such as wire, round tube or bar forms. Thus, it is able to provide an assessment of the product in its semi-finished form.4.4 This test method provides a simple method for determining transformation temperatures by heating and cooling specimens through their full thermal transformation under torque.4.5 This test method may also be used to evaluate partial transformation cycles as set by the LCT and UCT and agreed upon between the user and customer. Examples of partial and full transformation thermal cycles are provided in Fig. 2.FIG. 2 Effects of Shear Stress and Upper Cycle Temperature on Test ResultsNOTE 1: A) UCT sufficient for complete Austenitic transformation. B) UCT not sufficient for complete Austenitic transformation. “τ” is the applied shear stress.4.6 This test method can be used on trained and processed material in a semi-finished form to measure Two Way Shape Memory Effect (TWSME) by comparing the shear strain at the LCT and UCT with a torque set such that the corresponding shear stress shall not exceed 7 MPa. For determining TWSME in this manner it is suggested that a full transformation cycle be performed in accordance with 5.7.4.7 This test method is useful for quality control, specification acceptance, and research.4.8 Transformation temperatures derived from this test method may not agree with those obtained by other test methods due to the effects of shear strain and shear stress on the transformation.4.9 Components such as springs, specimens with non-circular cross-sections or other semi-finished parts can be tested using this method as agreed upon by the customer and supplier. Test parameters and results shall be determined with respect to torque and rotation measured at the ends of the active region of the specimen.1.1 This test method will define procedures for thermomechanical cycling of shape memory alloys (SMA) material and components with circular cross-sections under constant torque. This test method will measure the transformation properties such as transformation temperatures, actuation shear strain and residual shear strain, when a shape memory alloy is thermally cycled through the phase transformation under a constant applied torque. This test is done to provide data for the characterization selection of shape memory alloy materials, quality control, design allowables and actuator design.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in 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