Vulcanized rubber flexure test

Due to the viscoelasticity of rubber, all rubber will absorb part of the deformation energy and convert it into heat energy under the action of periodic deformation. The generation of thermal energy leads to an increase in temperature. Due to the poor thermal conductivity of rubber, the heat generated by deformation causes the internal temperature of thick rubber parts to reach a very high level. When the periodic deformation is large or the temperature rise is high, the rubber may break through fatigue, leading to damage. This damage starts on the inside of the rubber, then spreads to the outside, and can eventually lead to complete failure of the rubber part.
The vulcanized rubber flexure test can determine the temperature rise data or fatigue life of the rubber, that is, its durability when subjected to dynamic flexing. Zhongke Testing Reliability Experiment Center has the ability to test the reliability performance of various vulcanized rubbers and provides professional flexural testing services for vulcanized rubber.

Rubber products such as tires, rubber bearings, rubber supports, V-belts and sheave insert rings, etc.

1. Temperature rise test:
For the temperature rise test, it is generally recommended to select a test time long enough to fully achieve a balance between heat generation and heat dissipation of the sample. Taking measurements while the temperature is still rising is a source of error. To ensure that fatigue failure does not occur inside the specimen, lower stresses and strains should be used.
2. Fatigue life test:
When conditions permit, fatigue life should be determined at a range of different severity levels. And it is best to estimate the ultimate fatigue deformation capacity or ultimate fatigue stress before testing. An important factor to consider in fatigue testing is the method used to evaluate the onset of damage. Because damage usually begins inside the specimen and cannot be seen, this current method can only be indirect.
Sudden creep or temperature change is a sign of the beginning of damage. No matter which change occurs, the test should be stopped immediately and the inside of the sample should be checked for discoloration, pores, softening, etc.

GB/T 1687.1-2016 Determination of temperature rise and fatigue resistance of vulcanized rubber in flexure test Part 1: Basic principles
ISO 4666-1: 2010 Determination of temperature rise and fatigue resistance of vulcanized rubber in flexure tests Part 1: Basic principles
ISO 4664-1 Determination of dynamic properties of vulcanized rubber or thermoplastic rubber Part 1: General
ISO 23529 Rubber Physical Test Methods General Procedures for Specimen Preparation and Conditioning
GB/T 1687.4-2021 Vulcanized rubber Determination of temperature rise and fatigue resistance in flexure test Part 4: Constant stress flexure test