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定价： 156元 / 折扣价： 133 元 加购物车

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3.1 Vibration encountered in the field is not usually simple harmonic.3.2 This test can be used to determine relative motion between parts, critical frequencies, adhesion strengths, loosening of parts or other physical effects that can cause fatigue or failure.3.3 Experience has shown that this test will expose potential failures associated with the electronic components of a membrane switch, where tests of lower levels will not.3.4 This practice can be used to qualify a membrane switch for aerospace, medical and other applications.3.5 This test is potentially destructive, intended for device qualification.3.6 Either Test Condition A or B can be chosen, based upon the intent of the test determined by the qualified engineer.1.1 This test method establishes procedures for determining the effect of sinusoidal vibration, within the specified frequency range, on switch contacts, mounting hardware, adhered component parts, solder or heat stakes, tactile devices, and cable or ribbon interconnects associated with a membrane switch or membrane switch assembly.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： 0元 / 折扣价： 0 元

1 Scope 1.1 This International Standard specifies methods for measuring and reporting the whole body vibration to which the operator of an agricultural wheeled tractor or other field machine is exposed when operating on a standard test track. 1.2 T

定价： 774元 / 折扣价： 658 元

5.1 The material loss factor and modulus of damping materials are useful in designing measures to control vibration in structures and the sound that is radiated by those structures, especially at resonance. This test method determines the properties of a damping material by indirect measurement using damped cantilever beam theory. By applying beam theory, the resultant damping material properties are made independent of the geometry of the test specimen used to obtain them. These damping material properties can then be used with mathematical models to design damping systems and predict their performance prior to hardware fabrication. These models include simple beam and plate analogies as well as finite element analysis models.5.2 This test method has been found to produce good results when used for testing materials consisting of one homogeneous layer. In some damping applications, a damping design may consist of two or more layers with significantly different characteristics. These complicated designs must have their constituent layers tested separately if the predictions of the mathematical models are to have the highest possible accuracy.5.3 Assumptions: 5.3.1 All damping measurements are made in the linear range, that is, the damping materials behave in accordance with linear viscoelastic theory. If the applied force excites the beam beyond the linear region, the data analysis will not be applicable. For linear beam behavior, the peak displacement from rest for a composite beam should be less than the thickness of the base beam (See X2.3).5.3.2 The amplitude of the force signal applied to the excitation transducer is maintained constant with frequency. If the force amplitude cannot be kept constant, then the response of the beam must be divided by the force amplitude. The ratio of response to force (referred to as the compliance or receptance) presented as a function of frequency must then be used for evaluating the damping.5.3.3 Data reduction for both test specimens 2b and 2c (Fig. 2) uses the classical analysis for beams but does not include the effects of the terms involving rotary inertia or shear deformation. The analysis does assume that plane sections remain plane; therefore, care must be taken not to use specimens with a damping material thickness that is much greater (about four times) than that of the metal beam.5.3.4 The equations presented for computing the properties of damping materials in shear (sandwich specimen 2d—see Fig. 2) do not include the extensional terms for the damping layer. This is an acceptable assumption when the modulus of the damping layer is considerably (about ten times) lower than that of the metal.5.3.5 The equations for computing the damping properties from sandwich beam tests (specimen 2d—see Fig. 2) were developed and solved using sinusoidal expansion for the mode shapes of vibration. For sandwich composite beams, this approximation is acceptable only at the higher modes, and it has been the practice to ignore the first mode results. For the other specimen configurations (specimens 2a, 2b, and 2c) the first mode results may be used.5.3.6 Assume the loss factor (η) of the metal beam to be zero.NOTE 1: This is a well-founded assumption since steel and aluminum materials have loss factors of approximately 0.001 or less, which is significantly lower than those of the composite beams.5.4 Precautions: 5.4.1 With the exception of the uniform test specimen, the beam test technique is based on the measured differences between the damped (composite) and undamped (base) beams. When small differences of large numbers are involved, the equations for calculating the material properties are ill-conditioned and have a high error magnification factor, that is, small measurement errors result in large errors in the calculated properties. To prevent such conditions from occurring, it is recommended that:5.4.1.1 For a specimen mounted on one side of a base beam (see 10.2.2 and Fig. 2b), the term (fc/fn)2(1 + DT) should be equal to or greater than 1.01.5.4.1.2 For a specimen mounted on two sides of a base beam (see 10.2.3 and Fig. 2c), the term (fm/fn)2(1 + 2DT) should be equal to or greater than 1.01.5.4.1.3 For a sandwich specimen (see 10.2.4 and Fig. 2d), the term (fs/fn)2(2 + DT) should be equal to or greater than 2.01.5.4.1.4 The above limits are approximate. They depend on the thickness of the damping material relative to the base beam and on the modulus of the base beam. However, when the value of the terms in 5.4.1.1, 5.4.1.2, or 5.4.1.3 are near these limits the results should be evaluated carefully. The ratios in 5.4.1.1, 5.4.1.2, and 5.4.1.3 should be used to judge the likelihood of error.5.4.2 Test specimens Fig. 2b and Fig. 2c are usually used for stiff materials with Young's modulus greater than 100 MPa, where the properties are measured in the glassy and transition regions of such materials. These materials usually are of the free-layer type of treatment, such as enamels and loaded vinyls. The sandwich beam technique usually is used for soft viscoelastic materials with shear moduli less than 100 MPa. The value of 100 MPa is given as a guide for base beam thicknesses within the range listed in 8.4. The value will be higher for thicker beams and lower for thinner beams. When the 100 MPa guideline has been exceeded for a specific test specimen, the test data may appear to be good, the reduced data may have little scatter and may appear to be self-consistent. Although the composite beam test data are accurate in this modulus range, the calculated material properties are generally wrong. Accurate material property results can only be obtained by using the test specimen configuration that is appropriate for the range of the modulus results.5.4.3 Applying an effective damping material on a metal beam usually results in a well-damped response and a signal-to-noise ratio that is not very high. Therefore, it is important to select an appropriate thickness of damping material to obtain measurable amounts of damping. Start with a 1:1 thickness ratio of the damping material to the metal beam for test specimens Fig. 2b and Fig. 2c and a 1:10 thickness ratio of the damping material to one of the sandwich beams (Fig. 2d). Conversely, extremely low damping in the system should be avoided because the differences between the damped and undamped system will be small. If the thickness of the damping material cannot easily be changed to obtain the thickness ratios mentioned above, consider changing the thickness of the base beam (see 8.4).5.4.4 Read and follow all material application directions. When applicable, allow sufficient time for curing of both the damping material and any adhesive used to bond the material to the base beam.5.4.5 Learn about the characteristics of any adhesive used to bond the damping material to the base beam. The adhesive's stiffness and its application thickness can affect the damping of the composite beam and be a source of error (see 8.3).5.4.6 Consider known aging limits on both the damping and adhesive materials before preserving samples for aging tests.1.1 This test method measures the vibration-damping properties of materials: the loss factor, η, and Young's modulus, E, or the shear modulus, G. Accurate over a frequency range of 50 Hz to 5000 Hz and over the useful temperature range of the material, this method is useful in testing materials that have application in structural vibration, building acoustics, and the control of audible noise. Such materials include metals, enamels, ceramics, rubbers, plastics, reinforced epoxy matrices, and woods that can be formed to cantilever beam test specimen configurations.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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1. Scope 1.1 This Standard covers the procedures for the measurement of airborne sound (Clause 4) and ground-borne vibration (Clause 5) from blasting such as construction and quarrying. Note: This Standard should not be used for measurements of blas

定价： 319元 / 折扣价： 272 元

1 Scope This International Standard specifies, in accordance with ISO 10326-1, a laboratory method for measuring and evaluating the effectiveness of the suspension of operator seats on agricultural wheeled tractors. It also specifies acceptance criteri

定价： 728元 / 折扣价： 619 元

4.1 Shipping containers are exposed to complex dynamic stresses in the distribution environment. Approximating the actual damage, or lack of damage, experienced in real life may require subjecting the container and its contents to random vibration tests. In this way, many product and container resonances are simultaneously excited.4.2 Resonance buildups during random vibration tests are less intense than during sinusoidal resonance dwell or sweep tests. Therefore, unrealistic fatigue damage due to resonance buildup is minimized.4.3 Random vibration tests should be based on representative field data. When possible, confidence levels may be improved by comparing laboratory test results with actual field shipment effects. Refer to Practice D4169 for recommended random vibration tests. (See Appendix X1 and Appendix X2 for related information.)4.4 There is no direct equivalence between random vibration tests and sinusoidal vibration tests. Equivalent tests between sine and random, in a general sense, are difficult to establish due to nonlinearities, damping and product response characteristics.4.5 Vibration exposure affects the shipping container, its interior packing, means of closure, and contents. This test allows analysis of the interaction between these components. Design modification to one or all of these components may be used to achieve optimum performance in the shipping environment.4.6 Random vibration tests may be simultaneously performed with transient or periodic data to simulate known stresses of this type, that is, rail joints, pot holes, etc.4.7 Random vibration may be conducted in any axis (vertical or horizontal) or in any package orientation. However, different test levels may be utilized for each axis depending on the field environment that is to be simulated.1.1 This test method covers the random vibration testing of filled shipping units. Such tests may be used to assess the performance of a container with its interior packing and means of closure in terms of its ruggedness and the protection that it provides the contents when subjected to random vibration inputs.1.2 This test method provides guidance in the development and use of vibration data in the testing of shipping containers.NOTE 1: Sources of supplementary information are listed in the Reference section (1-11).21.3 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. Specific safety hazard statements are given in Section 6.1.4 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 / 折扣价： 502 元 加购物车

4.1 Shipping containers are exposed to complex dynamic stresses when subjected to vibration present in transportation vehicles. Approximating the actual damage, or lack of damage, experienced in shipping may require subjecting the container(s) and contents to vibration inputs.4.2 Resonant responses during shipment can be severe and may lead to failure of the container and spillage or leakage of contents. Identification of critical frequencies and the nature of package stresses can aid in minimizing the effect of these occurrences.4.3 This vibration test method is used for the qualification of IBCs in CFR 49 and has demonstrated successful use in transportation.4.4 Exposure to vibration can affect the shipping container, its means of closure, and its contents. This test method allows analysis of the interaction of these components. Design modification to one or more of these components may be utilized to achieve optimum performance in the shipping environment.4.5 This test method is suitable for individual filled containers that are transported unrestrained on the bed of a vehicle.4.6 This test method is not intended for testing intermediate bulk containers at a frequency that causes the container to go into resonance.1.1 This test method covers vibration testing of filled intermediate bulk containers (IBCs) intended to contain liquid hazardous materials (dangerous goods) and is suitable for testing IBCs of any design or material type. This test method is required as part of the qualification of IBCs in accordance with the United States Department of Transportation Title 49 Code of Federal Regulations (CFR) and the United Nations Recommendations on the Transport of Dangerous Goods (UN).1.2 This test method is appropriate for testing IBCs ranging from 450 to 3000 L (119 to 793 gal). Packagings of smaller sizes should be tested using Test Method D999 or other applicable methods.1.3 The ISO 2247 standard may not meet the requirements for this test method.1.4 This test method is based on the current information contained in 49 CFR, §178.819.1.5 This test method is used to determine that the IBC maintains integrity and to prevent leakage or spillage of contents during shipping. This test method may also be used as a screening tool or as a design qualification test. Other vibration methods are available to more closely simulate vibration experienced in actual transportation.1.6 When testing packaging designs intended for hazardous materials (dangerous goods), the user of this test method shall be trained in accordance with 49 CFR §172.700 and other applicable hazardous materials regulations such as the ICAO Technical Instructions, IMDG Code, and carrier rules such as the IATA Dangerous Goods Regulations.1.7 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.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. Specific precautionary statements are given in Section 6.1.9 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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1. Scope This International Standard specifies a laboratory method for vibration testing of operator seats for earth-moving machinery at frequencies between 1 Hz and 20 Hz. It is based on ISO 10326-1 which is a general method applicable to seats for

定价： 410元 / 折扣价： 349 元

4.1 Products are exposed to complex dynamic stresses in the transportation environment. The determination of the resonant frequencies of the product may aid the packaging designer in determining the proper packaging system to provide adequate protection for the product, as well as providing an understanding of the complex interactions between the components of the product as they relate to expected transportation vibration inputs.1.1 These test methods cover the determination of resonances of unpackaged products and components of unpackaged products by means of vertical linear motion at the surface on which the product is mounted for test. Two alternate test methods are presented:Test Method A—Resonance Search Using Sinusoidal Vibration, andTest Method B—Resonance Search Using Random Vibration.NOTE 1: The two test methods are not necessarily equivalent and may not produce the same results. It is possible that tests using random vibration may be more representative of the transport environment and may be conducted more quickly than sine tests.1.2 This information may be used to examine the response of products to vibration for product design purposes, or for the design of a container or interior package that will minimize transportation vibration inputs at these critical frequencies, when these products resonances are within the expected transportation environment frequency range. Since vibration damage is most likely to occur at product resonant frequencies, these resonances may be thought of as potential product fragility points.1.3 Information obtained from the optional dwell test methods may be used to assess the fatigue characteristics of the resonating components and for product modification. This may become necessary if the response of a product would require design of an impractical or excessively costly shipping container.1.4 These test methods do not necessarily simulate the vibration effects that the product will encounter in its operational or in-use environment. Other, more suitable test procedures should be used for this purpose.1.5 Test levels given in these test methods represent the correlation of the best information currently available from research investigation and from experience in the use of these test methods. If more applicable or accurate data are available, they should be substituted.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See Section 6 for specific precautionary statements.1.8 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 dynamic modulus of elasticity provided by these test methods is a fundamental property for the configuration tested.5.1.1 The rapidity and ease of application of these test methods facilitate their use as a substitute for static measurements.5.1.2 Dynamic modulus of elasticity is often used for surveys, for segregation of lumber for test purposes, for quality assessment of engineered wood products, and to provide indication of environmental or processing effect.5.2 The modulus of elasticity, whether measured statically or dynamically, is often a useful predictor variable to suggest or explain property relationships.5.3 Results from these test methods can be related to other measurements of modulus of elasticity, such as static methods (see Annex A1 and Appendix X4).5.4 These methods use calculations that assume specimens are prismatic in cross-section and are uniform in modulus of elasticity and density.5.4.1 As a result of the above assumptions, the obtained values of modulus of elasticity are dependent on how the specimen is stressed (see Commentary).5.4.2 Transverse vibration and longitudinal stress wave modulus of elasticity are correlated but not necessarily equal.5.4.3 These methods provide a means to establish a model to predict one dynamic modulus of elasticity from another dynamic method or a static method (that is, D198, D4761, etc.).5.4.4 The methods can also be used to estimate the Class I or Class II modulus of elasticity from the Class III method, or the Class I from the Class II method.5.5 Testing specified to be undertaken in accordance with this Method shall include any requirements regarding the following for each Class:5.5.1 Grades and species permitted to be combined to form the training and validation test sample.5.5.2 Selection and positioning of manufacturing or growth characteristics to be included or permitted in the test sample.5.5.3 Moisture content conditioning undertaken prior to testing.5.5.4 Acceptable moisture content adjustment models.5.5.5 Any other sampling and data adjustment requirements to obtain a representative sample of the population under consideration.NOTE 5: Guidance or requirements from applicable product standards or specifications for representative sampling should be considered. See Annex A2.NOTE 6: See Commentary Appendix X4 for additional information (for example, blocking parameter and blocking limits) that may need to be provided for generating a test sample suitable for developing the test method conversion model.1.1 These test methods cover the non-destructive determination of the following dynamic properties of wood and wood-based materials from measuring the fundamental frequency of vibration:1.1.1 Flexural (see Refs (1-3))2 stiffness and apparent modulus of elasticity (Etv) properties using simply or freely supported beam transverse vibration in the vertical direction, and1.1.2 Axial stiffness and apparent longitudinal modulus of elasticity (Esw) using stress wave propagation time in the longitudinal direction.1.2 The test methods can be used for a broad range of wood-based materials and products ranging from logs, timbers, lumber, and engineered wood products.1.2.1 The two flexural methods can be applied to flexural products such as glulam beams and I-joists.1.2.2 The longitudinal stress wave methods are limited to solid wood and homogeneous grade glulam (for example, columns but not products with distinct subcomponents such as wood I-joists).1.3 The standard recognizes three implementation classes for each of these test methods.1.3.1 Class I—Defines the fundamental method to achieve the highest degree of repeatability and reproducibility that can be achieved under laboratory conditions.NOTE 1: Testing should follow Class I methods to develop training and validation data sets for method conversion models (see Annex A2).1.3.2 Class II—Method with permitted modifications to the Class I method that can be used to address practical issues found in the field, and where practical deviations from the Class I protocol are known and their effects can be accounted.NOTE 2: Practical deviations include, for example, environmental and test boundary conditions. Class II methods allow for corrections to test results to account for quantifiable effect such as machine frame deflections.1.3.3 Class III—Method permitting the broadest range of application, with permitted modifications to suit a wider range of practical needs with an emphasis on repeatability.NOTE 3: Online testing machines implemented to grade/sort lumber may be treated as Class III.1.4 The standard provides guidance for developing a model for estimating a non-destructive test method result (for example, static modulus of elasticity obtained in accordance with Test Methods D198) from another non-destructive test method result (for example, dynamic longitudinal modulus of elasticity from measurement of longitudinal stress wave propagation time).1.4.1 The standard covers only models developed from test data obtained directly from non-destructively testing a representative sample using one test method, and retesting the same sample following a second test method.1.4.2 Results used for model development shall not be estimated from a model.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.

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