1.1 本试验方法包括测定结构材料的杨氏模量、切线模量和弦模量，见 图1 . 本试验方法仅限于与加载时立即产生的应变和弹性行为相比，蠕变可以忽略的材料以及温度和应力。 图1 应力-应变图，显示对应于( 一 )杨氏模量( b )切线模量，以及( c )弦模量 1.2 由于与建立应力-应变曲线原点相关的实验问题，如 8.1 ，确定初始切线模量（即应力斜率- 原点处的应变曲线）和割线模量不在本试验方法的范围内。 1.3 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 杨氏模量值是一种在设计中有用的材料属性，用于计算在承受单轴载荷时遵循胡克定律的结构材料的柔度（即应变与施加的力成比例）。 5.2 对于遵循非线性弹性应力应变行为的材料，切线模量或弦模量的值有助于估计特定应力范围内的应变变化。 5.3 由于对于许多材料，拉伸杨氏模量不同于压缩杨氏模量，因此应根据在相关应力模式下获得的试验数据得出。 5.4 仪器、试样和程序步骤的精度和精密度应符合被测材料和参考标准（如可用）。 5.5 精确测定杨氏模量需要适当考虑可能影响此类测定的众多变量。其中包括( 1. )试样的特征，例如相对于应力方向的晶粒方向、晶粒尺寸、残余应力、先前的应变历史、尺寸和偏心率；( 2. )测试条件，如试样对齐、测试速度、温度、温度变化、测试设备条件、施加力误差与力值范围的比率，以及测定中使用的延伸测量误差与延伸值范围的比率； 和( 3. )数据解释（参见第节 9 ). 5.6 当在超过0.25的应变下进行模量测定时 %, 应通过用瞬时横截面和瞬时标距代替原始值，对横截面面积和标距长度的变化进行校正。 5.7 压缩结果可能会受到桶装的影响（见试验方法 E9 ). 因此，应在此类影响最小的试样区域进行应变测量。

1.1 This test method covers the determination of Young's modulus, tangent modulus, and chord modulus of structural materials, see Fig. 1 . This test method is limited to materials in which and to temperatures and stresses at which creep is negligible compared to the strain produced immediately upon loading and to elastic behavior. FIG. 1 Stress-Strain Diagrams Showing Straight Lines Corresponding to ( a ) Young’s Modulus, ( b ) Tangent Modulus, and ( c ) Chord Modulus 1.2 Because of experimental problems associated with the establishment of the origin of the stress-strain curve described in 8.1 , the determination of the initial tangent modulus (that is, the slope of the stress-strain curve at the origin) and the secant modulus are outside the scope of this test method. 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 The value of Young’s modulus is a material property useful in design for calculating compliance of structural materials that follow Hooke's law when subjected to uniaxial loading (that is, the strain is proportional to the applied force). 5.2 For materials that follow nonlinear elastic stress-strain behavior, the value of tangent or chord modulus is useful in estimating the change in strain for a specified range in stress. 5.3 Since for many materials, Young's modulus in tension is different from Young's modulus in compression, it shall be derived from test data obtained in the stress mode of interest. 5.4 The accuracy and precision of apparatus, test specimens, and procedural steps should be such as to conform to the material being tested and to a reference standard, if available. 5.5 Precise determination of Young’s modulus requires due regard for the numerous variables that may affect such determinations. These include ( 1 ) characteristics of the specimen such as orientation of grains relative to the direction of the stress, grain size, residual stress, previous strain history, dimensions, and eccentricity; ( 2 ) testing conditions, such as alignment of the specimen, speed of testing, temperature, temperature variations, condition of test equipment, ratio of error in applied force to the range in force values, and ratio of error in extension measurement to the range in extension values used in the determination; and ( 3 ) interpretation of data (see Section 9 ). 5.6 When the modulus determination is made at strains in excess of 0.25 %, correction shall be made for changes in cross-sectional area and gauge length, by substituting the instantaneous cross section and instantaneous gauge length for the original values. 5.7 Compression results may be affected by barreling (see Test Methods E9 ). Strain measurements should therefore be made in the specimen region where such effects are minimal.