1.1 该试验方法确定了承受落锤冲击事件的多向聚合物基复合材料层合板的抗损伤性。复合材料形式仅限于连续纤维增强聚合物基复合材料，可接受的测试层压板和厚度范围见 8.2 . 1.1.1 实践中提供了修改这些程序以确定夹层结构抗损伤性能的说明 D7766/D7766M . 1.2 平面矩形复合板承受外载荷- 使用带有半球形冲击器的落锤装置进行平面集中冲击。在试验之前，规定了由冲击器的质量和跌落高度定义的落锤势能。提供了设备和程序，用于在碰撞事件期间选择性测量接触力和速度。损伤抗力根据试样中产生的损伤大小和类型进行量化。 1.3 该试验方法可用于筛选材料的抗损伤能力，或对试样造成损伤，以进行后续损伤容限试验。 当根据试验方法对受冲击板进行试验时 D7137/D7137M ，整个测试序列通常称为冲击后压缩（CAI）方法。每种试验方法的准静态压痕 D6264/D6264M 可作为从平面外力造成损伤和测量损伤阻力特性的替代方法。 1.4 该试验方法产生的抗损伤性能高度依赖于几个因素，包括试样几何形状、叠层、冲击器几何形状、冲击器质量、冲击力、冲击能量和边界条件。 因此，结果通常不可扩展到其他配置，并且特定于测试的几何和物理条件的组合。 1.5 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。 1.5.1 在文本中，英寸-磅单位显示在括号中。 1.6 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。 1.7 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 易受集中面外冲击力的损伤是许多由高级复合材料层压板制成的结构的主要设计问题之一。了解复合材料层合板的抗损伤性能有助于产品开发和材料选择。 5.2 落锤冲击试验可用于以下目的: 5.2.1 定量确定堆叠顺序、纤维表面处理、纤维体积分数变化以及加工和环境变量对特定复合材料层压板抗集中液滴损伤能力的影响- 重量冲击力或能量。 5.2.2 定量比较具有不同成分的复合材料的损伤抗力参数的相对值。损伤响应参数可以包括凹痕深度、损伤尺寸和贯穿厚度位置， F 1. , F 最大值 , E 1. 和 E 最大值 以及力-时间曲线。 5.2.3 在随后的损伤容限试验（如试验方法）中对试样施加损伤 D7137/D7137M . 5.3 使用该测试方法获得的特性可以为类似材料、厚度、堆叠顺序等的复合材料结构的预期抗损伤能力提供指导。 然而，必须理解，复合材料结构的抗损伤能力高度依赖于几个因素，包括几何形状、厚度、刚度、质量、支撑条件等。由于这些参数的差异，冲击力/能量和合成损伤状态之间的关系可能会产生显著差异。例如，使用该试验方法获得的性能更可能反映未加筋整体蒙皮或腹板的抗损伤特性，而不是附着在抵抗破坏的下部结构上的蒙皮的抗损伤特性- 平面变形。同样，与明显大于试样的板的性能相比，预计试样性能与具有等效长度和宽度尺寸的板的性能相似，后者倾向于将更大比例的冲击能量转移到弹性变形中。 5.4 标准碰撞块几何形状具有钝的半球形撞针尖端。从历史上看，对于标准层压板配置和冲击能量，与使用锋利撞针尖端的类似冲击相比，对于给定数量的外部损伤，该冲击器几何形状产生了更大的内部损伤。 根据正在检查的抗损伤特性，替代冲击器可能是合适的。例如，使用锋利的撞针尖端几何形状可能适用于某些损伤可见性和穿透阻力评估。 5.5 标准试验使用由试样厚度归一化的恒定冲击能量，定义见 11.7.1 . 一些测试机构可能希望将此测试方法与 D7137/D7137M 评估包含特定损伤状态（例如定义的凹痕深度、损伤几何形状等）的试样的压缩残余强度。 在这种情况下，测试机构应使用该测试方法在不同冲击能量水平下对多个试样或大型面板进行多次低速冲击。然后可以建立冲击能量和所需损伤参数之间的关系。然后，可以使用以预期产生所需损伤状态的内插能量水平冲击的试样进行后续落锤冲击和压缩残余强度试验。

1.1 This test method determines the damage resistance of multidirectional polymer matrix composite laminated plates subjected to a drop-weight impact event. The composite material forms are limited to continuous-fiber reinforced polymer matrix composites, with the range of acceptable test laminates and thicknesses defined in 8.2 . 1.1.1 Instructions for modifying these procedures to determine damage resistance properties of sandwich constructions are provided in Practice D7766/D7766M . 1.2 A flat, rectangular composite plate is subjected to an out-of-plane, concentrated impact using a drop-weight device with a hemispherical impactor. The potential energy of the drop-weight, as defined by the mass and drop height of the impactor, is specified prior to test. Equipment and procedures are provided for optional measurement of contact force and velocity during the impact event. The damage resistance is quantified in terms of the resulting size and type of damage in the specimen. 1.3 The test method may be used to screen materials for damage resistance, or to inflict damage into a specimen for subsequent damage tolerance testing. When the impacted plate is tested in accordance with Test Method D7137/D7137M , the overall test sequence is commonly referred to as the Compression After Impact (CAI) method. Quasi-static indentation per Test Method D6264/D6264M may be used as an alternate method of creating damage from an out-of-plane force and measuring damage resistance properties. 1.4 The damage resistance properties generated by this test method are highly dependent upon several factors, which include specimen geometry, layup, impactor geometry, impactor mass, impact force, impact energy, and boundary conditions. Thus, results are generally not scalable to other configurations, and are particular to the combination of geometric and physical conditions tested. 1.5 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. 1.5.1 Within the text, the inch-pound units are shown in brackets. 1.6 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. 1.7 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 Susceptibility to damage from concentrated out-of-plane impact forces is one of the major design concerns of many structures made of advanced composite laminates. Knowledge of the damage resistance properties of a laminated composite plate is useful for product development and material selection. 5.2 Drop-weight impact testing can serve the following purposes: 5.2.1 To establish quantitatively the effects of stacking sequence, fiber surface treatment, variations in fiber volume fraction, and processing and environmental variables on the damage resistance of a particular composite laminate to a concentrated drop-weight impact force or energy. 5.2.2 To compare quantitatively the relative values of the damage resistance parameters for composite materials with different constituents. The damage response parameters can include dent depth, damage dimensions, and through-thickness locations, F 1 , F max , E 1 , and E max , as well as the force versus time curve. 5.2.3 To impart damage in a specimen for subsequent damage tolerance tests, such as Test Method D7137/D7137M . 5.3 The properties obtained using this test method can provide guidance in regard to the anticipated damage resistance capability of composite structures of similar material, thickness, stacking sequence, and so forth. However, it must be understood that the damage resistance of a composite structure is highly dependent upon several factors, including geometry, thickness, stiffness, mass, support conditions, and so forth. Significant differences in the relationships between impact force/energy and the resultant damage state can result due to differences in these parameters. For example, properties obtained using this test method would more likely reflect the damage resistance characteristics of an unstiffened monolithic skin or web than that of a skin attached to substructure which resists out-of-plane deformation. Similarly, test specimen properties would be expected to be similar to those of a panel with equivalent length and width dimensions, in comparison to those of a panel significantly larger than the test specimen, which tends to divert a greater proportion of the impact energy into elastic deformation. 5.4 The standard impactor geometry has a blunt, hemispherical striker tip. Historically, for the standard laminate configuration and impact energy, this impactor geometry has generated a larger amount of internal damage for a given amount of external damage, when compared with that observed for similar impacts using sharp striker tips. Alternative impactors may be appropriate depending upon the damage resistance characteristics being examined. For example, the use of sharp striker tip geometries may be appropriate for certain damage visibility and penetration resistance assessments. 5.5 The standard test utilizes a constant impact energy normalized by specimen thickness, as defined in 11.7.1 . Some testing organizations may desire to use this test method in conjunction with D7137/D7137M to assess the compressive residual strength of specimens containing a specific damage state, such as a defined dent depth, damage geometry, and so forth. In this case, the testing organization should subject several specimens, or a large panel, to multiple low velocity impacts at various impact energy levels using this test method. A relationship between impact energy and the desired damage parameter can then be developed. Subsequent drop weight impact and compressive residual strength tests can then be performed using specimens impacted at an interpolated energy level that is expected to produce the desired damage state.