1.1 该试验方法确定了夹层复合材料板在分布荷载作用下的二维弯曲性能。测试夹具使用相对较大的方形面板样品，该样品简单地支撑在四周，并具有由充水囊状物提供的分布载荷。这种类型的载荷不同于试验方法的程序 C393 ，其中集中荷载引起梁试样的一维简单弯曲。 1.2 该试验方法适用于夹层型复合材料结构，该复合材料结构包括相对较厚的芯材层，该芯材层用粘合剂粘合在由密度更大、模量更高的材料（通常是用高模量纤维增强的聚合物基体）组成的薄面板上。 1.3 以国际单位制或英寸磅单位表示的数值应单独视为标准。在文本中，英寸磅单位显示在括号中。每个系统中规定的数值并不完全相等；因此，每个系统都必须独立使用。将两个系统的值结合起来可能会导致不符合标准。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 该试验方法模拟了实际夹层结构（如船体）中经常出现的静水载荷条件。该测试方法可用于比较由不同材料组合或不同制造工艺制成的夹层复合材料的二维弯曲刚度。由于它是基于分布式载荷而不是集中载荷，因此它还可以提供以类似方式加载的夹层结构的失效机制的更现实的信息。测试数据应该对设计和工程、材料规范、质量保证和工艺开发有用。此外，这种测试方法的数据将有助于完善预测数学模型或用作结构设计工具的计算机代码。 可通过该试验方法获得的特性包括: 5.1.1 荷载作用下的面板表面挠度， 5.1.2 面板面板在荷载下的应变， 5.1.3 面板弯曲刚度， 5.1.4 面板剪切刚度， 5.1.5 面板强度，以及 5.1.6 面板故障模式。

1.1 This test method determines the two-dimensional flexural properties of sandwich composite plates subjected to a distributed load. The test fixture uses a relatively large square panel sample which is simply supported all around and has the distributed load provided by a water-filled bladder. This type of loading differs from the procedure of Test Method C393 , where concentrated loads induce one-dimensional, simple bending in beam specimens. 1.2 This test method is applicable to composite structures of the sandwich type which involve a relatively thick layer of core material bonded on both faces with an adhesive to thin-face sheets composed of a denser, higher-modulus material, typically, a polymer matrix reinforced with high-modulus fibers. 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the 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 This test method simulates the hydrostatic loading conditions which are often present in actual sandwich structures, such as marine hulls. This test method can be used to compare the two-dimensional flexural stiffness of a sandwich composite made with different combinations of materials or with different fabrication processes. Since it is based on distributed loading rather than concentrated loading, it may also provide more realistic information on the failure mechanisms of sandwich structures loaded in a similar manner. Test data should be useful for design and engineering, material specification, quality assurance, and process development. In addition, data from this test method would be useful in refining predictive mathematical models or computer code for use as structural design tools. Properties that may be obtained from this test method include: 5.1.1 Panel surface deflection at load, 5.1.2 Panel face-sheet strain at load, 5.1.3 Panel bending stiffness, 5.1.4 Panel shear stiffness, 5.1.5 Panel strength, and 5.1.6 Panel failure modes.