1.1 本试验方法涵盖了结构材料剪切模量的测定。本试验方法仅限于与加载后立即产生的应变相比，蠕变可以忽略不计的材料和应力。剪切模量、杨氏模量和泊松比等弹性特性不是常规确定的，通常在材料规范中没有规定。 1.2 对于遵循非线性弹性应力-应变行为的材料，切线或弦剪切模量的值分别用于估计特定应力或应力范围内扭转应变到相应应力的变化。然而，此类测定不在本标准范围内。（参见示例Ref ( 1. ). ) 2. 1.3 单位- 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。 1.4 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。 1.5 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 剪切模量是一种在计算结构材料在扭转中的柔度时有用的材料特性，前提是它们遵循胡克定律，即扭转角度与施加的扭矩成比例。剪切模量的使用示例包括旋转轴和螺旋压缩弹簧的设计。 5.2 仪器和试样的程序步骤和精度应适合形状和材料类型，因为该方法适用于各种材料和尺寸。 5.3 剪切模量的精确测定取决于可能影响此类测定的众多变量。 5.3.1 这些因素包括试样的特性，如残余应力、同心度、管壁厚度、与标称值的偏差、先前的应变历史和试样尺寸。 5.3.2 影响结果的测试条件包括试样的轴向位置、温度和温度变化以及仪器的维护。 5.3.3 数据的解释也会影响结果。

1.1 This test method covers the determination of shear modulus of structural materials. This test method is limited to materials in which, and to stresses at which, creep is negligible compared to the strain produced immediately upon loading. Elastic properties such as shear modulus, Young's modulus, and Poisson's ratio are not determined routinely and are generally not specified in materials specifications. 1.2 For materials that follow nonlinear elastic stress-strain behavior, the value of tangent or chord shear modulus is useful for estimating the change in torsional strain to corresponding stress for a specified stress or stress-range, respectively. Such determinations are, however, outside the scope of this standard. (See for example Ref ( 1 ). ) 2 1.3 Units— 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 Shear modulus is a material property useful in calculating compliance of structural materials in torsion provided they follow Hooke's law, that is, the angle of twist is proportional to the applied torque. Examples of the use of shear modulus are in the design of rotating shafts and helical compression springs. 5.2 The procedural steps and precision of the apparatus and the test specimens should be appropriate to the shape and the material type, since the method applies to a wide variety of materials and sizes. 5.3 Precise determination of shear modulus depends on the numerous variables that may affect such determinations. 5.3.1 These factors include characteristics of the specimen such as residual stress, concentricity, wall thickness in the case of tubes, deviation from nominal value, previous strain history, and specimen dimension. 5.3.2 Testing conditions that influence the results include axial position of the specimen, temperature and temperature variations, and maintenance of the apparatus. 5.3.3 Interpretation of data also influences results.