How to determine the tensile properties of O?

Tensile property is a series of tests to determine the characteristics of O type ring under the action of tensile load. It is one of the basic methods of mechanical property testing, which is mainly used to test whether the materials meet the prescribed standards and study the properties of materials.

Test instrument

(1) this test is carried out on a tensile machine, and the tension machine shall conform to the relevant provisions of the 528-1998 GB/T "the determination of the tensile stress and strain properties of vulcanized rubber or thermoplastic rubber.". Guide rack device for pulling machine and device for measuring elongation of sample

(2) the test fixture is composed of the upper and lower two diameter at least 12mm with a ball bearing shaft wheel, when the two are close to each other, where the new distance is less than 25mm. The lower clamp is provided with a gear transmission device, and the guide rack gear on the pulling machine is combined at the test time.

(3) a straight line type test fixture using a general tensile test fixture, but need to ensure that the test process is constantly in the clamp

sample

(1) the diameter of the standard sample is 40mm + 0.3mm, and the cross section diameter is 3.55mm + 0.1mm. The number of samples is 5

(2) other dimensions using diameter greater than 40mm the O-ring, or cut pieces from the O-ring (on the linear sample length not less than 120mm) were determined, the results can not be compared with the standard sample results

Sample step

(1) to measure the diameter and diameter of the cross section of the sample. If the linear test sample is carried out in accordance with the method of section 4.2.4 and 4.2.5 of GB/T 528. The working distance is 25mm part marking

(2) the shaft wheel o trap as close as possible to the upper and lower clamp on the specimen under tensile stress, with good elongation measurement system, and adjust the zero point (i.e. determine the O-ring circumference elongation is equal to zero, the two wheel center distance)

(3) to start the machine (500 + 50) mm/min velocity tensile specimen, tensile load records to the specified elongation, load and elongation at break

The test results indicated, measurement results for 5 test results, taking the median of the calculated results, the elongation of rounding digits, the modulus and the tensile strength of a decimal.