1.1 本试验方法包括在环境温度下测定各向同性和近各向同性碳和石墨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合适（矩形或圆柱形）试样的几何形状、质量和机械共振频率，则可以计算该材料的动态弹性特性。动态杨氏模量是使用弯曲或纵向振动模式下的谐振频率来确定的。动态剪切模量，或刚度模量，是通过扭转共振找到的。动态杨氏模量和动态剪切模量用于计算泊松比。 1.2 该试验方法通过测量合适几何形状的试样的基本共振频率来确定弹性特性，方法是用脉冲工具通过奇异弹性冲击对试样进行机械激励。 选择试样支架、脉冲位置和信号拾取点来感应和测量瞬态振动的特定模式。换能器（例如，接触式加速度计或非接触式麦克风）感测样品产生的机械振动，并将其转换为电信号。（请参见 图1 .）分析瞬态信号，并通过信号分析仪隔离和测量基本谐振频率，信号分析仪提供与样品振动的频率或周期（或与之成比例）的数值读数。适当的基本谐振频率、尺寸和试样质量用于计算动态杨氏模量、动态剪切模量和泊松比。 附件A1 包含使用连续激励的替代方法。 图1 典型试验装置框图 1.3 以国际单位制表示的数值应视为标准。本标准中不包括其他计量单位。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ===意义和用途====== 5.1 该测试方法可用于材料开发、表征、设计数据生成和质量控制。 5.2 该试验方法主要涉及由均匀分布的碳或石墨颗粒组成的细长杆或棒的动态弹性模量和刚度的室温测定。 5.3 该试验方法可适用于初始应力-应变行为具有弹性的其他材料，如试验方法中所定义 E111 。 5.4 可以修改此基本测试方法，以确定–75温度下的弹性模量行为 °C至+2500 °C。薄石墨棒可用于将试样末端投影到环境温度条件下，以通过使用中所述的换能器提供谐振频率检测 7.1 。

1.1 This test method covers determination of the dynamic elastic properties of isotropic and near isotropic carbon and graphite materials at ambient temperatures. Specimens of these materials possess specific mechanical resonant frequencies that are determined by the elastic modulus, mass, and geometry of the test specimen. The dynamic elastic properties of a material can therefore be computed if the geometry, mass, and mechanical resonant frequencies of a suitable (rectangular or cylindrical) test specimen of that material can be measured. Dynamic Young's modulus is determined using the resonant frequency in the flexural or longitudinal mode of vibration. The dynamic shear modulus, or modulus of rigidity, is found using torsional resonant vibrations. Dynamic Young's modulus and dynamic shear modulus are used to compute Poisson's ratio. 1.2 This test method determines elastic properties by measuring the fundamental resonant frequency of test specimens of suitable geometry by exciting them mechanically by a singular elastic strike with an impulse tool. Specimen supports, impulse locations, and signal pick-up points are selected to induce and measure specific modes of the transient vibrations. A transducer (for example, contact accelerometer or non-contacting microphone) senses the resulting mechanical vibrations of the specimen and transforms them into electric signals. (See Fig. 1 .) The transient signals are analyzed, and the fundamental resonant frequency is isolated and measured by the signal analyzer, which provides a numerical reading that is (or is proportional to) either the frequency or the period of the specimen vibration. The appropriate fundamental resonant frequencies, dimensions, and mass of the specimen are used to calculate dynamic Young's modulus, dynamic shear modulus, and Poisson's ratio. Annex A1 contains an alternative approach using continuous excitation. FIG. 1 Block Diagram of Typical Test Apparatus 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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. ====== Significance And Use ====== 5.1 This test method may be used for material development, characterization, design data generation, and quality control purposes. 5.2 This test method is primarily concerned with the room temperature determination of the dynamic moduli of elasticity and rigidity of slender rods or bars composed of homogeneously distributed carbon or graphite particles. 5.3 This test method can be adapted for other materials that are elastic in their initial stress-strain behavior, as defined in Test Method E111 . 5.4 This basic test method can be modified to determine elastic moduli behavior at temperatures from –75 °C to +2500 °C. Thin graphite rods may be used to project the specimen extremities into ambient temperature conditions to provide resonant frequency detection by the use of transducers as described in 7.1 .