1.1 本规程涵盖完全由纤维/聚合物复合材料制成的面板和板状复合材料结构的声发射（AE）检查或监测。 1.2 声发射检测检测发射源，并定位发射源在复合结构内的区域。当适当制定了复合物项的基于声发射的标准时，声发射数据可用于无损检测（NDE）、验证测试的表征、质量控制文件，或用于完成计划测试之前与结构测试终止相关的决策。其他无损检测方法可用于提供有关定位损伤区域的附加信息。有关更多信息，请参阅 X1.1 在里面 附录X1 . 1.3 本规程可应用于航空航天复合材料面板和板状元件，作为制造期间、组装后、连续（结构健康监测期间）和结构寿命期间定期检查的一部分。 1.4 本规程适用于包括交叉层、角层压板或二维机织物的纤维取向。当第三个方向上的纤维含量小于5时，此做法也适用于三维钢筋（例如，缝合、z销） % （基于整个组合）。 1.5 本实践针对的是通常包含大于20 GPa[3 Msi]连续高模量纤维的复合材料。 1.6 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。 1.7 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。 1.8 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 声发射检测有助于检测新缺陷或现有缺陷的微损伤产生、累积和增长。该检测还用于检测在这些区域的加载或卸载过程中产生的基于摩擦的声发射造成的重大现有损伤。可以检测到的损伤机制包括基体开裂、纤维分裂、纤维断裂、纤维拔出、脱粘和分层。在加载、卸载和负载保持期间，不会检测到不发出声发射能量的损坏。 5.2 当声发射源的检测信号在时间上有足够的间隔，以便不被归类为连续声发射时，这种做法有助于定位2个声发射源的区域- D这些来源的测试样本，以及这些来源随负载或时间变化或两者的累积。 5.3 潜在声发射源的检测概率取决于损伤机制的性质、缺陷特征和其他方面。有关更多信息，请参阅 X1.4 . 5.4 纤维/聚合物复合材料中的集中损伤可能导致复合材料件过早失效。因此，使用声发射来检测和定位此类损伤尤为重要。 5.5 AE检测到的缺陷或损伤集中在某个区域，可通过其他无损检测技术（例如，视觉、超声波等）进一步表征，并可酌情修复。维修程序建议和随后的维修检查不在本规程范围内。有关更多信息，请参阅 X1.5 . 5.6 由于目前在该主题上发表的工作很少，导致缺乏足够的知识库，因此本实践不涉及夹层芯、泡沫芯或蜂窝芯板状复合材料。 5.7 请参阅指南 E2533 有关声发射检测到的缺陷类型的更多信息，适用于聚合物基复合材料的声发射概述，关于费利西蒂比（FR）和凯撒效应的讨论，优点和局限性，除平板外的复合材料零件的声发射，以及安全危害。

1.1 This practice covers acoustic emission (AE) examination or monitoring of panel and plate-like composite structures made entirely of fiber/polymer composites. 1.2 The AE examination detects emission sources and locates the region(s) within the composite structure where the emission originated. When properly developed AE-based criteria for the composite item are in place, the AE data can be used for nondestructive examination (NDE), characterization of proof testing, documentation of quality control, or for decisions relative to structural-test termination prior to completion of a planned test. Other NDE methods may be used to provide additional information about located damage regions. For additional information, see X1.1 in Appendix X1 . 1.3 This practice can be applied to aerospace composite panels and plate-like elements as a part of incoming inspection, during manufacturing, after assembly, continuously (during structural health monitoring), and at periodic intervals during the life of a structure. 1.4 This practice is meant for fiber orientations that include cross-plies, angle-ply laminates, or two-dimensional woven fabrics. This practice also applies to 3-D reinforcement (for example, stitched, z-pinned) when the fiber content in the third direction is less than 5 % (based on the whole composite). 1.5 This practice is directed toward composite materials that typically contain continuous high modulus greater than 20 GPa [3 Msi] fibers. 1.6 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. 1.7 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. 1.8 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 AE examination is useful to detect micro-damage generation, accumulation, and growth of new or existing flaws. The examination is also used to detect significant existing damage from friction-based AE generated during loading or unloading of these regions. The damage mechanisms that can be detected include matrix cracking, fiber splitting, fiber breakage, fiber pull-out, debonding, and delamination. During loading, unloading, and load holding, damage that does not emit AE energy will not be detected. 5.2 When the detected signals from AE sources are sufficiently spaced in time so as not to be classified as continuous AE, this practice is useful to locate the region(s) of the 2-D test sample where these sources originated and the accumulation of these sources with changing load or time, or both. 5.3 The probability of detection of the potential AE sources depends on the nature of the damage mechanisms, flaw characteristics, and other aspects. For additional information, see X1.4 . 5.4 Concentrated damage in fiber/polymer composites can lead to premature failure of the composite item. Hence, the use of AE to detect and locate such damage is particularly important. 5.5 AE-detected flaws or damage concentrated in a certain region may be further characterized by other NDE techniques (for example, visual, ultrasonic, etc.) and may be repaired as appropriate. Repair procedure recommendations and the subsequent examination of the repair are outside the scope of this practice. For additional information, see X1.5 . 5.6 This practice does not address sandwich core, foam core, or honeycomb core plate-like composites due to the fact that currently there is little in the way of published work on the subject resulting in a lack of a sufficient knowledge base. 5.7 Refer to Guide E2533 for additional information about types of defects detected by AE, general overview of AE as applied to polymer matrix composites, discussion of the Felicity ratio (FR) and Kaiser effect, advantages and limitations, AE of composite parts other than flat panels, and safety hazards.