1.1 该试验方法涵盖了使用固体层压板复合材料结构的无边和无边横截面配置的局部屈曲和致残应力。《指南》涵盖了试样的设计 D8511/D8511M .在标准范围内，许多测试参数可能会发生变化，前提是测试报告中充分记录了这些参数。复合材料形式仅限于连续纤维或不连续纤维（带、织物、编织物或这些形式的混合物）增强的复合材料。 1.2 这种测试方法需要仔细的样本设计、仪器、数据测量和数据分析。使用这种测试方法需要测试请求者和测试实验室人员之间的密切协调。 测试请求者需要熟悉指南 D8511/D8511M 和CMH-17第3卷第9章 2. ( 1. ) 。 1.3 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。每个系统中规定的值不一定是完全相等的；因此，为了确保符合标准，每个系统应独立使用，并且两个系统的值不得组合。 1.3.1 在文本中，英寸磅单位显示在括号中。 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 该试验方法旨在产生复合材料加劲肋横截面的局部屈曲和破坏数据，用于研究和开发以及结构设计和分析。该程序的标准通用配置提供了两种类型横截面段的数据:一种是无边横截面段，另一种是没有无边横截段。这类数据用于经典的加劲肋分析方法。 复合柱型试件的压缩荷载可能表现为四种模式之一: （1） 压缩材料强度失效， （2） 整体柱的弯曲、扭转和/或弯曲-扭转不稳定性， （3） 局部不稳定，随后持续的后屈曲承载能力，最终导致材料强度失效，或 （4） 局部和整体失稳的结合，随后发生屈曲后失效。前两种模式不在此测试方法的范围内。后两种模式被归类为严重失效，这也是本试验方法的目的。 5.1.1 期望的失效模式的特征在于初始线性弹性结构变形。 持续加载最终会使其中一个横截面段不稳定。超过该初始屈曲点的附加载荷表现出局部横向偏转或屈曲模式。这些挠度将增长，并可能改变模式，直到发生灾难性的立柱故障。这种破坏被认为是弯曲节段的最终破坏应力。 5.2 影响复合材料层压板机械响应的一般因素包括:材料、材料制备和铺设方法、试样堆叠顺序、试样制备、试样调节、试验环境、试样对齐和夹紧、试验速度、在试验温度下保持的时间、空隙率、，以及体积百分比增强。

1.1 This test method covers the local buckling and crippling stresses for one-edge-free and no-edge-free cross section configurations using solid laminate composite material construction. Design of test specimens is covered in Guide D8511/D8511M . A number of test parameters may be varied within the scope of the standard, provided that the parameters are fully documented in the test report. The composite material forms are limited to continuous-fiber or discontinuous-fiber (tape, fabric, braids or hybrids of these forms) reinforced composites. 1.2 This test method requires careful specimen design, instrumentation, data measurement and data analysis. The use of this test method requires close coordination between the test requestor and the test lab personnel. Test requestors need to be familiar with Guide D8511/D8511M and CMH-17 Volume 3 Chapter 9 2 ( 1 ) . 1.3 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. 1.3.1 Within the text the inch-pound units are shown in brackets. 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 is designed to produce composite stiffener cross-section local buckling and crippling data for research and development, and for structural design and analysis. The standard generic configurations for this procedure provide data for two types of cross-section segments: one-edge-free and no-edge-free. This type of data is used in classical stiffener analysis methods. Compressive loading of composite column type specimens may exhibit one of four modes: (1) a compression material strength failure, (2) an overall column flexural, torsional, and or flexural-torsional instability, (3) a local instability followed by a continued post-buckled force carrying capability which eventually results in a material strength failure, or (4) a combination of local and overall instability followed by post-buckling failure. The first two modes are outside the scope of this test method. The latter two modes are categorized as crippling failure and is the purpose of this test method. 5.1.1 The desired failure mode is characterized by an initial linear elastic structural deformation. Continued loading eventually renders one of the cross-sectional segments unstable. Additional loading beyond this point of initial buckling exhibits a pattern of local lateral deflections or buckles. These deflections will grow, and possibly change modes, until catastrophic column failure occurs. This failure is considered the ultimate crippling stress for the buckled segments. 5.2 General factors that influence the mechanical response of composite laminates and should therefore be reported include the following: 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 held at test temperature, void content, and volume percent reinforcement.