A Study on Fatigue Life of Marine Isolation Rubber Based on Crack Initiation Method

Uniaxial tension fatigue test (UTF) is often used in the field of fatigue life analysis of rubber materials. A UTF was conducted on a rubber material commonly used in marine rubber isolators, and the calculation method of its typical fatigue life was investigated by using the statistical method. Using the UTF data, seven different fatigue life evaluation parameters, such as maximum principal elongation rate and maximum principal engineering train, can be calculated. By fitting these parameters with the fatigue life obtained from the UTF, using the power-relation model, seven different fatigue life evaluation models based on these parameters can be established. The fitting effects of the seven models were compared and analyzed, and the results show that the model based on the maximum strain energy density has the optimized fitting performance. Therefore, using maximum strain energy density as the fatigue life evaluation parameter to analyze the fatigue life of rubber isolators can obtain more accurate results, which can be used to guide the structure and fatigue design of rubber isolators. As an example, the fatigue life of a marine rubber isolator is evaluated using the research results.