Tensile testing machine requirements for tensile testing

1. The sample to be tested should be uniform. For example, the length of the width and thickness of the board is 50 mm longer than the fixed length. The nominal width of the sample should not exceed 5 mm and not exceed 25.4 mm. The ratio of width to thickness is less than 8. The narrow sample increases the strain and cracks at the edge of the sample.

2. When using a tensile testing machine to measure the coefficient of elasticity, the length of the sample is 250mm, which is used to minimize the impact of clamping on the test results. When the length is not feasible, the length of the test area can reach 100mm without affecting the test result. But the length of 250mm is still used for arbitration. When testing short samples, the test rate should be adjusted so that the strain rate is equal to the standard sample.

3. When cutting samples with a tensile testing machine, avoid defects that may cause premature fracture of the samples. The two sides of the sample should be parallel, and the edge width should be less than 5% of the length between the two samples.

4. the suspicious material is anisotropic material. Two sets of samples should be prepared separately, the long axis of which should be parallel and perpendicular to the direction of anisotropy.

5. The thickness of the sample should remain unchanged. When the thickness of the sample is less than 10% of the length of the sample, the thickness of the material should be less than 0.25 mm. When the thickness of the material is greater than 0.25 mm and less than 100 mm, the thickness of the sample should be less than the fixed sample. 5% of the length.