1.1 这些试验方法包括通过测量振动基频对木材和木质材料的以下动态特性进行无损检测: 1.1.1 弯曲（参见参考文献 ( 1- 3. ) ) 2. 刚度和表观弹性模量( E 电视 )在垂直方向上使用简单或自由支撑梁横向振动的特性，以及 1.1.2 轴向刚度和表观纵向弹性模量( E 软件 )使用纵向上的应力波传播时间。 1.2 试验方法可用于广泛的木质材料和产品，包括原木、木材、木材和工程木材产品。 1.2.1 这两种弯曲方法可应用于胶合板梁和工字托梁等弯曲产品。 1.2.2 纵向应力波法仅适用于实木和均质胶合板（例如，立柱，但不适用于具有不同子部件的产品，如I型木托梁）。 1.3 该标准为每个测试方法识别三个实现类。 1.3.1 I类- 定义了在实验室条件下实现最高重复性和再现性的基本方法。 注1: 测试应遵循I类方法，为方法转换模型开发培训和验证数据集（参见 附件A2 ). 1.3.2 II类- 允许对I类方法进行修改的方法，可用于解决现场发现的实际问题，且已知与I类协议的实际偏差，并可考虑其影响。 注2: 实际偏差包括，例如，环境和试验边界条件。II类方法允许对试验结果进行修正，以考虑可量化的影响，如机架挠度。 1.3.3 III类- 方法允许最广泛的应用范围，允许修改以适应更广泛的实际需求，强调重复性。 注3: 用于分级/分类木材的在线试验机可被视为III类。 1.4 本标准为开发估算无损检测方法结果的模型提供了指导（例如，根据测试方法获得的静态弹性模量 第198页 )根据另一非破坏性测试方法结果（例如通过测量纵向应力波传播时间获得的动态纵向弹性模量）。 1.4.1 本标准仅涵盖从使用一种测试方法对代表性样品进行非破坏性测试以及使用第二种测试方法重新测试相同样品中直接获得的测试数据中开发的模型。 1.4.2 用于模型开发的结果不得根据模型进行估算。 1.5 以英寸磅单位表示的值应视为标准值。括号中给出的值是对SI单位的数学转换，仅供参考，不被视为标准。 1.6 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 这些测试方法提供的动态弹性模量是测试配置的基本特性。 5.1. 1. 这些测试方法的快速性和易用性有助于将其用作静态测量的替代品。 5.1.2 动态弹性模量通常用于测量、试验用木材的分离、工程木材产品的质量评估，以及提供环境或加工效果的指示。 5.2 弹性模量，无论是静态测量还是动态测量，通常是一个有用的预测变量，用于建议或解释属性关系。 5.3 这些测试方法的结果可以与弹性模量的其他测量相关，例如静态方法（参见 附件A1 和 附录X4 ). 5.4 这些方法使用的计算假定试样的横截面为棱柱形，弹性模量和密度均匀。 5.4.1 由于上述假设，获得的弹性模量值取决于试样的应力方式（见注释）。 5.4.2 横向振动和纵向应力波弹性模量相关，但不一定相等。 5.4.3 这些方法提供了建立模型的手段，以从另一动态方法或静态方法（即， 第198页 , 第4761页 等）。 5.4.4 这些方法还可用于根据III类方法估算I类或II类弹性模量，或根据II类方法估算Ⅰ类弹性模量。 5.5 根据本方法规定进行的试验应包括每种等级的以下要求: 5.5.1 允许将等级和物种组合起来形成培训和验证测试样本。 5.5.2 选择和定位测试样品中包含或允许的制造或生长特性。 5.5.3 测试前进行的含水量调节。 5.5.4 可接受的含水量调整模型。 5.5.5 任何其他抽样和数据调整要求，以获得所考虑人群的代表性样本。 注5: 应考虑适用产品标准或规范对代表性取样的指导或要求。 看见 附件A2 . 注6: 见注释 附录X4 用于生成适合于开发测试方法转换模型的测试样本可能需要提供的附加信息（例如，阻塞参数和阻塞限制）。

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 ( E tv ) properties using simply or freely supported beam transverse vibration in the vertical direction, and 1.1.2 Axial stiffness and apparent longitudinal modulus of elasticity ( E sw ) 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. ====== Significance And Use ====== 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.