Tensile testing machine fixture slipping solution

In response to the above-mentioned reasons for slippage caused by human factors and equipment factors, Shanghai Heyi Instrument Technology Co., Ltd. has formulated the following countermeasures, which can reduce or eliminate the slippage of the tension machine through the implementation of countermeasures.

1. Specification of the operating procedures of the testing machine

For the short clamping length of the specimen and the improper selection of the clamp of the clamp, in the operating procedure of the electronic tensile testing machine, it must be specified: "The clamping length of the tensile specimen shall not be less than the length of the tooth surface of the clamp" and "No" Use a jaw for a large section to hold a small section specimen or a flat jaw to hold a large specimen. The operator must test according to the operating procedures.

2. Repair the wedge bevel

Plastic deformation and severe eversion of the wedge block, so that the wedge block slope collapse or wear should be repaired in time, the repair can generally take the following two methods

2.1, repair welding

The trapped or worn parts of the wedge block are first repaired and then restored by the inserting machine (should be scraped if the machining does not meet the roughness requirements). The hardness and strength of the repaired parts are generally improved, and it is ok to use the jig correctly later.

2.2, mosaic

The wedge-shaped block slope is removed by inserting the bed by 10 mm according to the original design angle, and then a polished hardened steel plate is placed in this part, which weakens the design strength of the clamp body, but the long-term use effect is better.

2.3 Adding a layer protection device above the wedge block

In order to prevent the metal oxide sample from falling into the wedge-shaped slope during the stretching process, two rubber blocks can be placed on the wedge shape, so that the iron oxide skin can be effectively reduced to fall into the inclined surface, and the wedge-shaped bevel can be coated with butter. Or grease, and scrub and change the oil regularly.

Electronic tensile testing machine fixture slippage summary

The probability of slippage of the electronic tensile testing machine during the tensile test is relatively high, mainly due to the slippage of the clamping part of the specimen or the existence of a large gap between the transmission points of certain force values ​​of the testing machine. If the test is used before. The test yield value of the machine is normal, and the test yield value will be significantly lower now, and it is especially obvious when testing some hard or brittle materials. Generally, the reason why the test machine slips should be considered first. At this time, it is necessary to analyze the cause of the slippage in time, and take corresponding measures for the reasons to ensure the accuracy of our test data.