[0004] The authorized utility model patent CN 206990327U provides a compression fixture for a uniaxial tensile
creep testing machine. This scheme uses the existing uniaxial tensile
creep testing machine to realize the test of material compression creep performance. This method is suitable for thick and short, The creep performance test of samples with a large
diameter-to-height ratio, but the test of slender samples with uneven end surfaces has great limitations. On the indenter, the
coincidence with the sample axis is poor, and the test accuracy of the creep value is not high through the displacement of the indenter.
The authorized utility model patent CN 204422329U discloses a compression fixture on a mechanical tensile creep testing machine. This invention can complete the compression creep test on the existing mechanical tensile creep
endurance testing machine. One end of the sample is connected with the adjustment Ball head contact, when the parallelism of both ends of the sample is not high, the ball head plane is not horizontal, the force is not horizontal to the axis, and the spherical contact does not
restrict the rotation, and the sample is easy to bend in the
compression testThe authorized utility model patent CN 207147874U relates to a fixture for testing compression creep aging on an electronic
universal testing machine. When the fixture is used for testing, the sample itself does not need to be clamped, and it only needs to be placed in the place where the sample is clamped. It is easy to use. However, this fixture is only suitable for linear samples. For rod-shaped samples with external threads at both ends, the clamping accuracy is not enough, and the threads are easy to be damaged, which will affect the subsequent experiments. Moreover, the structure of the fixture is relatively complicated, and the experimental operation space is small , it is not easy to install the sample and has a significant
impact on the distribution of the temperature field, which is not conducive to carrying out creep experiments in the creep machine
The authorized invention patent CN 107063851A discloses a high-temperature compression fixture. This patent provides a
test fixture for testing material compression performance indicators in a high-temperature environment. The tensile force is converted into pressure through cross-connected upper and lower compression bodies. The compression performance test is carried out by means of tension, but the two ends of the fixture sample are not fixed, and it is easy to cause sliding to cause the sample to bend, and the whole fixture needs to be disassembled when carrying out the experiment, which is inconvenient for actual operation, and frequent disassembly will affect the The fixture itself has a great influence and shortens the service life
The authorized utility model patent CN203798673U provides a
test fixture for testing the compression
performance index of materials in high temperature environment. The fixture uses the principle of
relative motion to realize the method of converting the tensile performance test of the material into the compression performance test. The briquettes are squeezed together to compress the sample. This fixture cannot be centered when performing a slender rod-shaped sample test. There is no clamping device at both ends of the sample, so the displacement of the creep test cannot be accurately measured, and the sample is relatively large. It is difficult to process the fixture cavity and through holes for a long time, the cost is high, and the accuracy is difficult to guarantee, which has a great
impact on the results of creep experiments that require high displacement accuracy
[0005] The authorized invention patent CN 104374646A discloses a mechanical creep
extensometer, which provides a new
extensometer that can clamp bar samples with different diameters and different gauge lengths. Good versatility and high measurement accuracy, but when carrying out the
compression test, the compression of the sample is converted into the compression of the sensor head. When the sample becomes unstable and bent, the compression will increase rapidly, exceeding the
stroke of the measuring head, resulting in high Damage to precision displacement sensors
The authorized utility model CN 201016904Y discloses a
metal room temperature creep test tool, which can measure the elongation of the creep sample. The working process is stable and the volume is small. However, the tool needs to be in the same environment as the At
room temperature, the high temperature creep test cannot be carried out, and the precision displacement sensor will be damaged when the sample is unstable and damaged
The authorized utility model CN207703621U relates to a quick-clamping extension device for creep tests. Through simple operation, it can meet the test
assembly requirements and improve the clamping speed. However, when carrying out compression tests, the high-precision displacement sensor is located in the test On both sides of the sample, the
instability and bending of the sample will cause the sensor to over-travel, which in turn will cause damage to the high-precision displacement sensor
[0006] In summary, there is a need for a solution in the prior art to solve the problems of
instability and bending caused by the misalignment of the force and axis of the sample that are prone to occur during creep compression experiments, as well as the displacement after instability and bending. The problem that the sensor measuring head is damaged due to overtravel