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GB/T 35465 Test method for fatigue properties of polymer matrix composite materials is divided into three parts:
—— Part 1: General principle;
—— Part 2: Statistical analysis of linear or linearized stress-life(S-N) and strain-life (ε-N) fatigue data;
—— Part 3: Tension-tension fatigue.
This is Part 3 of GB/T 35465.
This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 16779-2008 Test method for tension-tension fatigue of fiber reinforced plastic laminates, and the following main changes have been made with respect to GB/T 16779-2008:
—— the name of the standard is changed from Test method for tension-tension fatigue of fiber reinforced plastic laminates into Test method for fatigue properties of polymer matrix composite materials - Part 3: Tension-tension fatigue;
—— the scope is modified from “the medium value S-N curve and condition fatigue limit of tension-tension fatigue” to “tension-tension fatigue properties test under cyclic loading conditions of constant amplitude and frequency” (see Clause 1 of this standard and Clause 1 of Edition 2008);
—— the normative references are modified (see Clause 2 of this standard and Clause 2 of Edition 2008);
—— the term “condition fatigue limit” is deleted; other terms are in accordance with GB/T 35465.1 (see Clause 3 of this standard and Clause 3 of Edition 2008)
—— the theory is modified and the description of fatigue control for strain-control is added (see Clause 4 of this standard and Clause 4 of Edition 2008);
—— the test equipment is modified (see Clause 5 of this standard and Clause 5 of Edition 2008);
—— the dimensions of vertical bar type specimens are modified, and forms and dimensions of fully processed type specimens are added (see 6.1 of this standard and 6.1 of Edition 2008);
—— the preparation and quantity requirements of specimen are modified (see 6.2 of this standard, 6.2 and 6.3 of Edition 2008);
—— detailed test operation procedures are modified and added, including main requirements for test grading, strain-based control parameters, and record for failure mode (see Clause 8 of this standard and Clause 8 of Edition 2008)
—— the test results processing method is modified, from calculated according to HB/Z112 to GB/T 35465.2 (see Clause 9 of this standard and Clause 9 of Edition 2008);
—— the test report is modified (see Clause 10 of this standard and Clause 10 of Edition 2008);
—— the test typical failure mode is added (see Annex A).
This part was proposed by China Building Materials Federation.
This standard is under the jurisdiction of National Technical Committee on Fiber Reinforced Plastics of Standardization Administration of China (SAC/TC 39).
The previous editions of this part are as follows:
—— GB/T 16779-1997 and GB/T 16779-2008.
Test method for fatigue properties of polymer matrix composite materials - Part 3: Tension-tension fatigue
1 Scope
This part of GB/T 35464 specifies the terms and definitions, theory, test equipment, specimen, conditioning and test environment, test procedures, test results and data processing, and test report of test method for fatigue properties of polymer matrix composite materials.
This part applies to the tension-tension fatigue properties test of polymer matrix composite materials under cyclic loading conditions of constant amplitude and frequency.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1447 Fiber-reinforced plastics composites - Determination of tensile properties
GB/T 3354 Test method for tensile properties of orientation fiber reinforced polymer matrix composite materials
GB/T 35465.1 Test method for fatigue properties of polymer matrix composite materials - Part 1: General principle
GB/T 35465.2 Test method for fatigue properties of polymer matrix composite materials - Part 2: Statistical analysis of linear or linearized stress-life (S-N) and strain-life (ε-N) fatigue data
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 1447, GB/T 3354, and GB/T 35464.1 and the following apply.
3.1
tension-tension fatigue
the maximum stress and the minimum stress are both fatigue under tensile stress
4 Theory
Under different tensile stress or strain levels, alternating stress or strain shall be applied to the specimen with constant stress or strain amplitude, stress ratio or strain ratio, and frequency, until the specimen fails. Test results shall be analyzed and treated to draw stress-life (S-N) or strain-life (ε-N) curves
5 Test equipment
5.1 The test equipment shall meet the requirements of GB/T 35465.1.
5.2 Fixtures and ancillary equipment shall ensure that no relative slip of the specimen occurs during the test.
5.3 The dimension measuring tool shall be accurate to 0.01 mm.
6 Specimens
6.1 Shape and dimension of the specimens
The specimen is divided into vertical bar type and dumbbell-shaped type. In special needs, the fully processed type specimen may also be adopted. Vertical bar type and dumbbell-shaped specimens shall be adopted for unidirectional laminates, vertical bar type and dumbbell-shaped specimens may be adopted for other laminates, and dumbbell type specimen shall be adopted for the non-laminates such as molded chopped felt. The shapes of the vertical bar type specimen are shown in Figure 1, see Table 1 for the dimensions; see Figures 2 and 3 for the shapes and dimensions of the dumbbell-shaped specimen and fully processed type specimen.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Theory 5 Test equipment 6 Specimen 7 State adjustment and test environment 8 Test procedure 9 Test results and data processing 10 Test report Annex A (Informative) Typical failure modes
ICS.83.120 Q23 GB 中华人民共和国国家标准 GB/T 35465.3-2017 代替GB/T 16779-2008 聚合物基复合材料疲劳性能测试方法 第3部分：拉-拉疲劳 Test method for fatigue properties of polymer matrix composite materials-Part 3：Tension-tension fatigue 2017-12-29发布 2018-11-01实施 中华人民共和国国家质量监督检验检疫总局 中国国家标准化管理委员会 发布
d）第四个水平以1×106至2×106循环次数为目标。 8.7通常从第一个水平开始疲劳试验.若循环次数与预期差异较大，则逐量升高或降低应力或应变水平。玻璃纤维增强塑料推荐的疲劳水平为静态拉伸强度或静态拉伸失效应变的75%、55%、40%、30%；碳纤维增强塑料推荐的疲劳水平为静态拉伸强度或静态拉伸失效应变的50%、65%、55%、45%。若无特殊试验目的，各应力或应变水平应使用相同频率和应力或应变比。 8.8夹持试样并使试样中心线与上下夹头的对准中心线一致。若进行应变控制，安装应变仪或其他应变测量装置，并在无载荷时对应变清零。 8.9对试样加载直至试样失效或达到协定失效条件（如刚度下降20%）。在试验过程中.监测试样表面温度。若试样温度变化超过10℃，启用散热装置。若散热装置不能降低试样的温度，需重新选择试验频率。 注：试样没有失效或未达到协定失效条件，此类数据不为疲劳寿命。 8.10试样失效后，应保护好试样断口。检查失效模式，特别注意加强片边缘或夹持部位产生的破坏。去除所有不可接受的试样并补充试验。典型的失效模式参见附录A. 8.11试验过程中随时检查设备状态，观察试样的变化，每水平至少记录一根试样的温度。 9试验结果及数据处理 9.1 给出所有试样的疲劳寿命 9.2按GB/T36465.2的规定进行数据处理，并检验应力寿命（S-N）或应变寿命（ε-N）曲线。 10试验报告 试验报告应符合GB/T35465.1的规定。 附录A 资料性附录 典型失效模式 A.1试样失效代码见表A.1. 表A.1拉-拉疲劳试验试样失效代码 第一个字母 第二个字母 第三个字母 失效形式 代码 失效区域 代码 失效部位 代码 角辅层破坏 A 夹持/加强片内部 I 固定端 B 边缘分层 D 夹持/加强片根部 A 主动端 T 夹持破坏或加强片脱落 G 距离夹持/加强片 小于1倍宽度 W 左侧 L 横向 L 右侧 R 多模式 M(■) 工作段 G 中侧 M 纵向劈裂 S 多处 M 散丝 X 其他 O A.2可接受破坏和不可接受破坏的典型失效模式见图A.1所示。
