Clamps serve as a vital component in universal testing machines, and their design and condition significantly impact the test results. Universal testing machines are widely used in material mechanics testing to measure mechanical properties such as strength, toughness, and stiffness by applying force or torque. In this process, clamps play a crucial role in holding the specimen and ensuring smooth progression of the test.

The selection and design of clamps are of utmost importance. Different materials require different clamps, and improper selection or unreasonable design can lead to specimen slippage or displacement during testing, thereby affecting the accuracy of the test results. Additionally, clamp wear is also a significant factor. The use of severely worn clamps can result in poor clamping effects, further compromising the reliability of test results.

In practical operations, the installation of clamps and the clamping method of specimens also have a significant impact on test results. For instance, in wire winding clamps, wire-on-wire pressing can cause localized stress concentrations, resulting in specimen fracture at the pressed area and poor fracture point alignment. For wedge-shaped clamps, special attention should be paid to specimen centering. If installed askance, uneven force distribution on both sides of the specimen may lead to tearing or poor fracture point alignment.

By comparing the test results obtained with new and old clamps, the influence of clamp condition on test results can be clearly observed. When using new clamps, test duration is reduced, and wear on both the clamps and universal testing machine is minimized, thus better ensuring the accuracy and longevity of the tests. Meanwhile, the clamping effect of new clamps is far superior to that of old clamps, resulting in more prominent yield points on the obtained curves and a more accurate reflection of the specimen's mechanical properties.

In summary, the selection, design, installation, and condition of clamps all have significant impacts on the test results of universal testing machines. To ensure the accuracy of test results, it is necessary to reasonably select and correctly use clamps, as well as regularly inspect and maintain their condition.