Experimental Study On Damage Problems Of Rubber Material

Rubber material has excellent mechanical properties such as super-elastic, nonlinear large deformation and low modulus. It is widely used in machinery manufacturing, transportation, communication and aerospace electrical fields. Rubber products are in low-cycle stress state during the long service period. It is easy to failure under the complexity external factors such as loading speed, load amplitude and temperature which may lead to serious consequences. So scholars attach more attention on rubber material’s reliability study. But due to the mechanical properties of rubber material is quite complex which makes the theoretical analysis on reliability become very sophisticated. The damage regulation of rubber material is studied under uniaxial tensile and cyclic loading experimental conditions in this paper. It is also affected by speed, temperature, pre-strain and other factors which are focused on by this paper. The main work of this paper is as following:1、In uniaxial tensile tests, using the different loading speeds and temperatures,analysised the influence of loading speeds and temperature for the damage amount of rubber material. And using the damage parameter of maximum principal stress peak and area method calculate the damage amount in different loading speeds and temperatures:The improve of loading speeds will increase the damage of the material in nonlinearly.And the magnitude of increase in damage will gradually reduced with speed increases. Influence of temperature for damage is complicated.In the lower temperature range(20~70℃), the damage will increase with logarithmic form; In the higher temperature range(70~90℃), the amplitude variation of damage is small for discrete change; In the high temperature range(100~120℃), the variations of injury is different from the lower temperature, the amount of damage is declined.2、In cyclic loading tests, using the different loading speeds、temperatures and pre-strain,analysised the influence of loading speeds、temperature and pre-strain for the damage amount of rubber material. And using the damage parameter of maximum principal stress peak、strain energy density peak、area method and elastic modulus method calculate the damage amount in different loading speeds and temperatures:The damage increased in the form of a logarithmic with loading speeds increasing;The damage is reduced with the temperature increase under the same cyclic loading way;When pre-strain small(0~0.3 ?), the damage increase with prestrain increasing in small amplitude,after that the growth rate of damage will continue to rise.3、Rubber material applied a certain degree of pre-strain in cyclic loading test, compare with test results of cyclic loading for test pieces keep certain period of time under some prestrain. Comparing the influence of damage for rubber material in different pre-strain under two different experimental methods: Damaged increased with increase of prestrain, the magnitude of the material damage keeping in a strain state for some time significantly lower than the magnitude of the material damage in cyclic loading.