Systematic operation and daily maintenance plan for carbon fiber board tensile compression bending testing equipment

1、 Equipment Overview

This equipment is mainly used for testing the static mechanical properties of carbon fiber board and carbon fiber reinforced composite materials (CFRP), such as tension, compression, and bending. It can accurately determine key mechanical parameters such as tensile strength, elastic modulus, elongation at break, compression strength, and bending strength of the materials. The equipment adopts high-precision servo motor drive and fully digital closed-loop control technology, supporting three control modes of force, displacement, and deformation. The measurement accuracy is better than ± 0.5%, meeting the requirements of domestic and foreign testing standards such as ISO 527, ASTM D3039, ASTM D7264, etc.

2、 Safety precautions

Equipment placement and calibration: After the equipment is in place, it must be calibrated with a spirit level, with a horizontal error of less than or equal to 0.5mm/m; The power supply line should be routed separately to avoid sharing with other high-power equipment.

Calibration before use: Full scale calibration must be performed using standard weights.

Limit protection confirmation: Before starting up, check whether the upper and lower limit devices are working properly and confirm that the electronic limit protection function is enabled.

Overloading operation is prohibited: It is strictly forbidden to operate beyond the rated load of the equipment. The software has overload protection function (automatic parking at 10% overload).

Protective device: During the test, the protective door must be closed and hands are prohibited from entering the test area.

3、 Operation flow

（1） Power on and device preparation

Connect the main power supply and sequentially turn on the power supply of the testing machine host and the computer.

Start the testing software and check if the device communication is normal.

Install corresponding fixtures or test attachments according to the type of test (tension/compression/bending) to ensure a secure installation.

（2） Sample preparation and measurement

Prepare specimens according to relevant standards: tensile specimens refer to ASTM D3039 or GB/T 3354, compressive specimens refer to ASTM D6641 or GB/T 1448, and bending specimens refer to ASTM D7264 or GB/T 1449.

Measure the width and thickness at different positions of the sample working section at least three times with a caliper, and take the arithmetic mean as the basis for calculating the cross-sectional area.

For tensile specimens, clearly mark the original gauge length within the working section.

If pasting reinforcement sheets, it is necessary to ensure that the adhesive is completely cured and that the reinforcement sheets do not affect the stress on the working section of the sample.

（3） Sample installation

Tensile test: Place one end of the specimen vertically into the upper fixture and slightly pre tighten it. Adjust the crossbeam and place the other end of the specimen into the lower fixture, ensuring that the longitudinal axis of the specimen coincides with the centerline of the fixture. Tighten the upper and lower fixtures evenly.

Compression test: The compression fixture must ensure good contact between the loading surface and the specimen end face. When using a combination loading compression fixture, the sample installation must be completed on a granite flat plate, ensuring that the end of the sample is flush with the fixture base plane. Use a torque wrench to tighten the bolts in three times according to the standard specified torque (such as 3 N · m specified in ASTM D6641).

Bending test: Place the specimen freely on the two supports of the three-point bending fixture, and align the center line of the loading head with the midpoint of the two supports, with a deviation controlled within ± 0.5mm.

（4） Experimental parameter setting

Select the test type (tension/compression/bending) in the software.

Enter sample size parameters (width, thickness, gauge length, etc.).

Set loading rate: The tensile test is usually carried out in accordance with GB/T 1447 regulations; The compression test shall be carried out in accordance with relevant standards; The loading rate of the bending test should ensure a quasi-static loading state.

Select the control mode (force control, displacement control, or deformation control) and set the protection limit.

Force and displacement are reset to zero.

5） Perform testing

Click the 'Start Test' button, and the device will automatically load.

During the experiment, closely monitor the force displacement curve displayed by the software and the status of the specimen. If any abnormalities are found, immediately press the emergency stop button.

After the sample breaks or reaches the preset shutdown conditions, the equipment automatically stops.

（6） Data recording and result processing

The software automatically records results such as force and elongation at break, and generates stress-strain curves.

Check the failure mode of the sample and confirm whether the failure location is within the working section. If there is ineffective damage such as breakage at the fixture or crushing at the end, the sample data should be excluded.

Each group shall have no less than 5 valid samples, and the statistical average shall be taken as the final result.

Test reports containing sample information, test conditions, test results, and curve graphs can be exported or printed.

（7） Shut down

After the experiment is completed, return the moving crossbeam to its initial position.

Remove the sample and fixture, and clean the testing area.

Exit the testing software and turn off the computer and host power.

Turn off the main power supply.

4、 Daily maintenance and upkeep

Cleaning: Regularly clean the surface and internal components of the equipment to remove dust and sample debris.

Lubrication: Regularly add an appropriate amount of lubricating oil to transmission components such as lead screws.

Calibration: Calibrate the force sensor and displacement sensor according to the measurement cycle (usually one year).

Fixture inspection: Regularly check the wear of the fixture teeth, and it is recommended that the clamping force of the wedge-shaped fixture be ≥ 120N.