Specific steps for tensile testing of carbon fiber cloth

The specific steps of the carbon fiber cloth tensile test can refer to the carbon fiber multifilament tensile test method under the GB/T 3362 standard. The following is a detailed analysis of the steps:

1. Preparation
- Test equipment: prepare material tensile testing machine, contact extensometer, pneumatic clamp and other test equipment.
- Sample preparation: Cut the carbon fiber cloth into standard specimens to ensure that the size and shape of the specimens are consistent.

2. Test process

2.1 Determination of multifilament linear density
- Fix one end of the carbon fiber cloth and use the weight of the weight to add tension to the other end. The mass of the weight is 1%~2% of the maximum load of the multifilament.

2.2 Determination of fiber body density
- It can be measured by the floating and sinking method or the density gradient method. The floating and sinking method requires adding reagents and stirring with a glass rod, letting it stand for about 30 minutes and then observing whether the fibers are evenly distributed.

2.3 Sample preparation
- Dip the carbon fiber cloth in a certain concentration of resin curing system solution, take it out and fix it on the glue rack, then put the glue rack in the oven to heat and cure, remove the cured rod-shaped specimen, make a reinforcement sheet according to the size requirements, and finally conduct a tensile test.

2.4 Clamp the sample
- Use a pneumatic clamp to clamp the sample in the upper and lower clamps of the material tensile testing machine, ensuring that the center line of the sample coincides with the center line of the clamp to avoid the occurrence of oblique pulling. Ensure that when clamping the sample, the end of the sample is parallel and perpendicular to the clamp to ensure uniform application of the tensile load.

2.5 Set test parameters
- Set the test temperature to room temperature, which meets the predetermined test conditions. Set the test type to tensile test and select the tensile rate, generally the conventional tensile rate, to maintain the stability of the test.

2.6 Preload setting
- Set the preload value, usually 1% of the maximum load of the multifilament sample. Ensure that the preload setting value must be greater than or equal to the product of the maximum range and accuracy of the tensile tester sensor to ensure data accuracy.

2.7 Test
- Start the tensile test, and the tensile tester will gradually apply the load to the set value. When the preload value is reached, the initial length of the specimen is fixed, the elongation returns to zero, but the load does not return to zero, and the actual tensile test begins. During the test, observe the reading of the contact extensometer in real time and record the elongation changes of the specimen.

2.8 Data Recording and Analysis
- Record the load and elongation data during the test for subsequent analysis. According to the data obtained from the test, calculate the tensile strength and tensile modulus of the carbon fiber cloth.

3. Result Analysis
- According to the test data, calculate the tensile strength and tensile modulus of the carbon fiber cloth to evaluate whether its mechanical properties meet the standard requirements.

Through the above steps, the carbon fiber cloth tensile test can be systematically carried out to ensure the accuracy and reliability of the test results.