考虑尺寸效应的近海桥梁天然橡胶隔震支座力学性能老化时变规律研究

Now, most of the studies for natural rubber bearing's (NRB) performance do not consider the size effect. Given our previous research on the time-varying law of NRB and its rubber material used in offshore bridges, the NRB's performance was studied considering both the diameter size of NRB and the aging time in this study. Firstly, ABAQUS was used to analyze the performance of NRB with different diameters to find the change law of NRB's performance with diameter size under the condition that the thickness of rubber layers and inner steel plates varies proportionally with the diameter size but the number of laminated layers and the shape coefficient remain unchanged. Then, the change trend of the NRB's performance considering the effect of diameter size and aging time was studied, combined with the research results mentioned above. Finally, the horizontal and vertical stiffness of NRB under the influence of both diameter size and aging time, were simulated and the simulation results were compared with the calculation results to verify the accuracy of the proposed change law of NRB performance under the effect of diameter size and aging time. Results show that diameter size has a significant effect on both the horizontal and vertical stiffness of NRB. The aging time also has a significant effect on the horizontal stiffness but has little effect on the vertical stiffness. This research can offer a reference for the design of the scale model test of isolated bridge structure and also can provide information for the application of the relevant study results of the small-size rubber bearing in design and calculation of practical engineering.