1.1 本试验方法包括通过将V形缺口试样的端部夹在两对加载轨道之间来测定高模量纤维增强复合材料的剪切性能。当加载张力时，钢轨通过试样表面将剪切力引入试样。相比之下，试验方法的样本 D5379/D5379M 通过其顶部和底部边缘加载。如果需要，表面载荷允许对试样施加更大的剪切力。此外，本试验方法使用的试样比试验方法中的V形缺口试样具有更大的计量截面 D5379/D5379M . 在这两种试验方法中，使用V形切口试样相对于夹具附近的剪切应力增加了标距截面剪切应力，从而将破坏定位在标距截面内，同时使剪切应力分布比没有切口的试样中更均匀。 相比之下，试验方法 D4255/D4255M 利用夹在张力加载的两对加载轨道之间的无缺口样本。此外，与试验方法相比 D4255/D4255M ，本试验方法提供了试样夹持，而不需要在试样上开孔。 复合材料仅限于以下材料形式的连续纤维或不连续纤维增强复合材料: 1.1.1 层压板仅由单向纤维层组成，纤维方向平行或垂直于夹具导轨。 1.1.2 平衡对称结构的层压板，0°方向平行或垂直于夹具导轨。 1.1.3 由机织物、编织物或针织物组成的层压板。 1.1.4 大多数纤维随机分布的短纤维增强复合材料。 1.2 单位- 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 1.2.1 在文本中，英寸-磅单位显示在括号中。 1.3 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。 1.4 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 该剪切试验旨在为材料规范、研发、质量保证以及结构设计和分析提供剪切性能数据。 根据材料坐标系相对于加载轴的方向，可以评估平面内或层间剪切特性。因此，应报告影响剪切响应的因素包括:材料、材料制备和铺层方法、样本堆叠顺序、样本制备、样本调节、测试环境、样本对齐和夹持、测试速度、温度下的时间、空隙率和钢筋体积百分比。 5.2 在各向异性材料中，通过将试样的测试平面与所需的材料平面定向，可以在六个可能的剪切平面中的任何一个获得特性( 1-2 或 2-1 , 1-3 或 3-1 , 2-3 或 3-2 ). 对于任何给定的试样，只能评估单个剪切面。可从本试验方法中获得的试验方向上的特性包括: 5.2.1 剪应力与工程剪应变响应， 5.2.2 极限抗剪强度， 5.2.3 极限工程剪应变，以及 5.2.4 剪切弦弹性模量。

1.1 This test method covers the determination of the shear properties of high-modulus fiber-reinforced composite materials by clamping the ends of a V-notched specimen between two pairs of loading rails. When loaded in tension, the rails introduce shear forces into the specimen through the specimen faces. In comparison, the specimen of Test Method D5379/D5379M is loaded through its top and bottom edges. Face loading allows higher shear forces to be applied to the specimen, if required. Additionally, the present test method utilizes a specimen with a larger gage section than the V-notched specimen of Test Method D5379/D5379M . In both test methods, the use of a V-notched specimen increases the gage section shear stresses in relation to the shear stresses in the vicinity of the grips, thus localizing the failure within the gage section while causing the shear stress distribution to be more uniform than in a specimen without notches. In comparison, Test Method D4255/D4255M utilizes an unnotched specimen clamped between two pairs of loading rails that are loaded in tension. Also, in contrast to Test Method D4255/D4255M , the present test method provides specimen gripping without the need for holes in the specimen. The composite materials are limited to continuous-fiber or discontinuous-fiber-reinforced composites in the following material forms: 1.1.1 Laminates composed only of unidirectional fibrous laminae, with the fiber direction oriented either parallel or perpendicular to the fixture rails. 1.1.2 Laminates of balanced and symmetric construction, with the 0° direction oriented either parallel or perpendicular to the fixture rails. 1.1.3 Laminates composed of woven, braided, or knitted fabric filamentary laminae. 1.1.4 Short-fiber-reinforced composites with a majority of the fibers being randomly distributed. 1.2 Units— The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.2.1 Within the text, the inch-pound units are shown in brackets. 1.3 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. 1.4 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 shear test is designed to produce shear property data for material specifications, research and development, quality assurance, and structural design and analysis. Either in-plane or interlaminar shear properties may be evaluated, depending upon the orientation of the material coordinate system relative to the loading axis. Factors that influence the shear response and should therefore be reported include: material, methods of material preparation and lay-up, specimen stacking sequence, specimen preparation, specimen conditioning, environment of testing, specimen alignment and gripping, speed of testing, time at temperature, void content, and volume percent reinforcement. 5.2 In anisotropic materials, properties may be obtained in any of the six possible shear planes by orienting the testing plane of the specimen with the desired material plane ( 1-2 or 2-1 , 1-3 or 3-1 , 2-3 or 3-2 ). Only a single shear plane may be evaluated for any given specimen. Properties, in the test direction, which may be obtained from this test method, include the following: 5.2.1 Shear stress versus engineering shear strain response, 5.2.2 Ultimate shear strength, 5.2.3 Ultimate engineering shear strain, and 5.2.4 Shear chord modulus of elasticity.