1.1 本试验方法包括测定弹性材料的动态弹性特性。这些材料的试样具有特定的机械共振频率，该频率由试样的弹性模量、质量和几何形状决定。因此，如果可以测量材料的适当试样的几何形状、质量和机械共振频率，则可以计算材料的动态弹性特性。使用基本弯曲共振频率确定动态杨氏模量。动态剪切模量或刚度模量是使用基本扭转共振频率求得的。动态杨氏模量和动态剪切模量用于计算泊松比。 1.2 本试验方法特别适用于弹性、均匀和各向同性材料( 1. ). 2. 1.3 具有复合特性（颗粒、晶须或纤维增强）的材料可通过本试验方法进行试验，但应了解试样中增强体的特性（体积分数、尺寸、形态、分布、方向、弹性性能和界面粘结）将直接影响弹性性能。在解释复合材料的试验结果时，应考虑这些增强效应。 1.4 本试验方法不得用于测定各向异性材料的泊松比。 注1: 对于各向异性材料，泊松比在不同方向上可能有不同的值。由于各向异性材料中缺乏对称性，弹性张量不能简化为两个独立的数，并且 E , G ，并且µ无效。 1.5 本试验方法不适用于具有裂纹或孔隙的试样，这些裂纹或孔隙是试样中的主要不连续性。 1.6 当材料不能制成均匀的矩形或圆形横截面时，不应使用该试验方法。 1.7 描述了一种高温炉和低温室，用于测量动态弹性模量，作为-195温度的函数 °C至1200 °C。 1.8 本试验方法可修改以用于质量控制。确定具有特定几何形状和质量的试样的可接受共振频率范围。频率响应不在此频率范围内的任何样本均被拒收。只要已知选定频率范围的极限包括试样必须具有的共振频率（如果其几何形状和质量在规定公差范围内），则无需确定每个试样的实际模量。 1.9 有一些特定于材料的ASTM标准，包括通过声波共振或振动冲击激励来确定特定材料的共振频率和弹性特性。试验方法 C215型 , C623 , C747 , C848 , C1198 , C1259 和 C1548 在几个方面与本试验方法不同（例如:试样尺寸、尺寸公差、试样制备）。这些材料的测试应符合这些材料特定标准。在可能的情况下，程序、试样规格和计算与这些试验方法一致。 1.10 单独的标准、测试方法 E1876 ，通过冲击激励而不是声共振来确定动态弹性模量。 1.11 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.12 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.13 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 与使用静态加载系统测量模量相比，该测试方法在某些方面具有优势。 5.1.1 本试验方法本质上是无损的。 仅对试样施加微小应力，从而将断裂的可能性降至最低。 5.1.2 施加和消除测量应力的时间约为数百微秒。使用该试验方法可以在高温下进行测量，在高温下，延迟弹性和蠕变效应将使根据静态载荷计算的弹性模量测量无效。 5.2 如果认识到材料通常对热历史敏感的一个重要事实，则该测试方法适用于检测材料是否符合规范。因此，在将模量的实验值与参考值或标准值进行比较时，必须考虑试样的热历史。试样说明应包括试样已接受的任何特定热处理。

1.1 This test method covers the determination of the dynamic elastic properties of elastic materials. Specimens of these materials possess specific mechanical resonant frequencies that are determined by the modulus of elasticity, mass, and geometry of the test specimen. Therefore, the dynamic elastic properties of a material can be computed if the geometry, mass, and mechanical resonant frequencies of a suitable test specimen of that material can be measured. The dynamic Young's modulus is determined using the fundamental flexural resonant frequency. The dynamic shear modulus, or modulus of rigidity, is found using the fundamental torsional resonant frequency. Dynamic Young's modulus and dynamic shear modulus are used to compute Poisson's ratio. 1.2 This test method is specifically appropriate for materials that are elastic, homogeneous, and isotropic ( 1 ). 2 1.3 Materials of a composite character (particulate, whisker, or fiber reinforced) may be tested by this test method with the understanding that the character (volume fraction, size, morphology, distribution, orientation, elastic properties, and interfacial bonding) of the reinforcement in the test specimen will have a direct effect on the elastic properties. These reinforcement effects shall be considered in interpreting the test results for composites. 1.4 This test method shall not be used for determination of Poisson’s ratio of anisotropic materials. Note 1: For anisotropic materials, Poisson’s ratio can have different values in different directions. Due to the lack of symmetry in anisotropic materials, the elasticity tensor cannot be reduced to only two independent numbers, and the simplified relation between E , G , and µ is not valid. 1.5 This test method should not be used for specimens that have cracks or voids that are major discontinuities in the specimen. 1.6 The test method should not be used when materials cannot be fabricated in a uniform rectangular or circular cross section. 1.7 An elevated-temperature furnace and cryogenic chamber are described for measuring the dynamic elastic moduli as a function of temperature from –195 °C to 1200 °C. 1.8 This test method may be modified for use in quality control. A range of acceptable resonant frequencies is determined for a specimen with a particular geometry and mass. Any specimen with a frequency response falling outside this frequency range is rejected. The actual modulus of each specimen need not be determined as long as the limits of the selected frequency range are known to include the resonant frequency that the specimen must possess if its geometry and mass are within specified tolerances. 1.9 There are material-specific ASTM standards that cover the determination of resonant frequencies and elastic properties of specific materials by sonic resonance or by impulse excitation of vibration. Test Methods C215 , C623 , C747 , C848 , C1198 , C1259 , and C1548 differ from this test method in several areas (for example; specimen size, dimensional tolerances, specimen preparation). The testing of these materials shall be done in compliance with these material specific standards. Where possible, the procedures, specimen specifications, and calculations are consistent with these test methods. 1.10 A separate standard, Test Method E1876 , governs determination of dynamic elastic moduli by impulse excitation instead of sonic resonance. 1.11 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.12 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. 1.13 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 This test method has advantages in certain respects over the use of static loading systems for measuring moduli. 5.1.1 This test method is nondestructive in nature. Only minute stresses are applied to the specimen, thus minimizing the possibility of fracture. 5.1.2 The period of time during which measurement stress is applied and removed is of the order of hundreds of microseconds. With this test method it is feasible to perform measurements at elevated temperatures, where delayed elastic and creep effects would invalidate modulus of elasticity measurements calculated from static loading. 5.2 This test method is suitable for detecting whether a material meets the specifications, if cognizance is given to one important fact in materials are often sensitive to thermal history. Therefore, the thermal history of a test specimen must be considered in comparing experimental values of moduli to reference or standard values. Specimen descriptions should include any specific thermal treatments that the specimens have received.