Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 3362-2005 Test Methods for Tensile Properties of Carbon Fiber Multifilament. The following main technical changes have been made with respect to GB/T 3362-2005:
——The restriction requirements for carbon fiber multifilament are modified, from 1 K~12 K to 1 K~24 K (see Chapter 1; Chapter 1 of Edition 2005);
——The chapter "Principle" is deleted (see Chapter 4 of Edition 2005);
——Requirements for automatic record of load-displacement curve by a tester is added (see 4.1);
——Type of recommended clamp is added (see 4.3);
——Width of stiffener is modified, from 20mm to 10 mm~20 mm (see 5.1.2; 6.1.2 of Edition 2005);
——Type and thickness of specimen stiffener are modified, and metal plate stiffener is deleted; the following requirements are added: for carbon fiber multifilament specimens below 6K, 0.2 mm~0.5 mm thick paper or paperboard applies; for carbon fiber multifilament specimens of 6K or above, 0.3 mm~1.0 mm thick paper or paperboard applies (see 5.2.4; 6.2.4 of Edition 2005);
——The sticking method for stiffeners to carbon fiber multifilament specimens of 6K or above is modified [see 5.2.4; 6.2.4 and Figure 1b) of Edition 2005];
——The loading rate in arbitration test is modified, from 2mm/min to 10mm/min (see 6.2; 7.2 of Edition 2005);
——Loading and unloading for the extensometer in the test procedures are added (see 7.5 and 7.6);
——Corresponding relationship to the strain value range during measurement of the modulus of elasticity (see Table 1);
——The calculation formula of the tensile modulus of elasticity is modified (see 8.2; 9.2 of Edition 2005);
——The calculation method for elongation at break is modified (see 8.3; 9.3 of Edition 2005);
——For impregnating adhesive, the resin system that can be cured at room temperature is added (see Annex A; Annex A of Edition 2005);
——The determination method of carbon fiber multifilament density is deleted, which is replaced by direct reference to GB/T 30019 (Annex C of Edition 2005).
This standard was proposed by China Building Materials Federation.
This standard is under the jurisdiction of the National Technical Committee on Fiber Reinforced Plastics of Standardization Administration of China (SAC/TC 39).
The previous editions of the standard replaced by this standard are as follows:
——GB/T 3362-1982, GB/T 3362-2005.
Test Methods for Tensile Properties of Carbon Fiber Multifilament
1 Scope
This standard specifies apparatus, specimens, test conditions, test procedures, calculation of test results and test report for test methods for tensile properties of carbon fiber multifilament.
This standard is applicable to determination of tensile strength, tensile modulus of elasticity and elongation at break of gummed and cured 1 K~24 K carbon fiber multifilament.
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 1446 The Generals of Test Methods for Properties of Fiber-reinforced Plastics
GB/T 30019 Carbon Fiber—Determination of Density
3 Terms and Definitions
For the purposes of this document, the following term and definition apply.
3.1
multifilament
A kind of filament, threadlet made by multi-hole spinnerette or twisted/untwisted yarn from such threadlet
4 Apparatus
4.1 Tester: complying with GB/T 1446, automatic record of load-displacement curve.
4.2 Extensometer: extensometer weight has no influence on the measuring accuracy that shall meet the requirements of GB/T 1446.
4.3 Clamp: it, when connected with the tester, shall ensure that the specimen is centered during tension; a clamp shall be suitable for clamping specimens with paper as stiffener, and pneumatic clamping should be adopted.
4.4 Drying oven: temperature meets specimen curing requirements and temperature control accuracy is not less than ±2℃.
5 Specimens
5.1 Specimen quantity, shape and dimension
5.1.1 10 specimens are measured for each group of tests. In each group of testing, effective specimens shall not be less than 6.
5.1.2 Specimen shape and dimension are as shown in Figure 1.
Dimensions in millimeters
Keys:
1——Carbon fiber multifilament;
2——Stiffener.
Figure 1 Schematic Diagram of Specimen Shape and Dimension
5.2 Specimen preparation
5.2.1 Specimens are made of carbon fiber multifilament impregnated in epoxy resin adhesive (see Annex A for the formula of resin adhesive).
5.2.2 Carbon fiber multifilament may be gummed manually or mechanically (see Annex A for manual gumming).
5.2.3 Carbon fiber multifilament shall be cut according to specimen dimension after gumming and curing. Specimens shall be gummed uniformly, smoothly and straightly, without defects. For gummed multifilament specimens, resin content shall be controlled within the range of 35%~50%.
5.2.4 Paper or paperboard as stiffener is adhered to both sides of the specimen. For carbon fiber multifilament specimens below 6K, 0.2 mm~0.5 mm thick paper or paperboard applies; for carbon fiber multifilament specimens of 6K or above, 0.3 mm~1.0 mm thick paper or paperboard applies. Stiffeners may be stuck with epoxy adhesive cured at room temperature.
6 Test Conditions
6.1 The test environment shall meet the requirements of GB/T 1446.
6.2 Loading rate is 1 mm/min~20 mm/min. In arbitration test, the loading rate is 10 mm/min.
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Apparatus
5 Specimens
6 Test Conditions
7 Test Procedures
8 Calculation of Test Results
9 Test Report
Annex A (Informative) Preparation of Resin Adhesive for Impregnating Carbon Fiber Multifilament and Manual Gumming Method
Annex B (Normative) Determination for Linear Density of Carbon Fiber Multifilament
