Tensile performance is a series of tests to determine the characteristics of rubber O-ring under tensile load, also known as tensile test. It is one of the basic methods of material mechanical properties test, mainly used to test whether the material meets the specified standards and to study the performance of the material.
Test instrument
(1) This test is carried out on a tension machine, which shall comply with the relevant provisions of GB/T 528-1998 "Determination of tensile stress and strain properties of vulcanized rubber or thermoplastic rubber". The tension machine shall have a guide rack device and a device for measuring sample elongation
(2) The test fixture is composed of two shaft wheels with ball bearings of at least 12mm in diameter, and when the two wheels are close to each other, the new distance is within 25mm. The lower fixture is equipped with a gear transmission device, which should be fitted with the guide rack of the tension machine during the test
(3) The linear test fixture uses the universal tensile test fixture, but it is necessary to ensure that the test sample is constantly in the clamp during the test process
sample
(1) The inner diameter of the standard sample is 40mm±0.3mm, and the section diameter is 3.55mm±0.1mm. The number of samples is 5
(2) O-rings of other sizes with an inner diameter greater than 40mm, or segments cut from O-rings (linear samples with a length of not less than 120mm) can be measured, and the results cannot be compared with the results of standard samples
Sample step
(1) Measure the section diameter and inner diameter of the specimen as specified. If the sample is linear, the method of 4.2.4 and 4.2.5 in GB/T 528 shall be followed. The line spacing of the working part is 25mm
(2) The rubber O-shaped trap is placed on the shaft wheel of the upper and lower fixture as close as possible, so that the sample is not subject to tensile stress, connect the elongation measurement system, and adjust the zero point (that is, when the elongation of the inner circumference of the O-ring is equal to zero, the center distance between the two shaft wheels).
(3) Start the machine to stretch the sample at the speed of (500±50) mm/min, record the load when the sample is stretched to the specified elongation, the load and elongation when it is broken
There are 5 measurement results ----. The median of the calculated results is taken as the test result, the entire digit of the elongation at break, and one decimal place of the constant extension stress and tensile strength are taken as the test result.