Development of a modified Mooney-Rivlin constitutive model for rubber to investigate the effects of aging and marine corrosion on seismic isolated bearings

In this study,aging and marine corrosion tests of a large number of rubber material and rubber bearings have been carried out.The constitutive Mooney-Rivlin model parameters for a rubber isolated bearing have been determined.By applying the least-square method to the experimental data,the relationships between the aging time and the marine corrosion time with the constants in the constitutive model for a rubber bearing have been derived.Next,the Mooney-Rivlin model has been modified accordingly.Further,using the modified Mooney-Rivlin model and the Abaqus software,the performance of the rubber isolated bearings has been simulated.The simulation results have been compared to the experimental results so as to verify the accuracy of the modified model.The comparison shows that the maximum errors for the vertical and horizontal stiffnesses are 16.8%and 0.49%,respectively.Since these errors are considered acceptable,the accuracy of the modified constitutive model can be considered verified.The results of this study can provide theoretical support for the performance study on rubber isolated bearings under the complex ocean environment and the life-cycle performance evaluation of bridges and other offshore structures.