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Based on a system of macro & micro fracture appearance observation, energy spectrum analysis and metallurgical structure inspection, the cause of sample crack of Q345 steel were obtained. The results showed that the specimen occurred fatigue crack under alternating load, the crack source was a line source, the middle area of the fracture was the relatively flat topography and relatively narrow fatigue striations, the rear area of the fracture was the relatively uneven topography and relatively large fatigue striations, and a certain yield occurred at the crack tip.

The fatigue damage test of metal rubber vibration isolator is performed, the result of which shows that fatigue damage performance of metal rubber is different from conventional solid materials. The damage of metal rubber which is accumulated with its inner partial broken and wore wires, results in deterioration of its macro-mechanical characteristic, macro-cracking and final fatigue failure, so it does not rupture as sudden failure of solid material. It is difficult to describe damage evolution of metal rubber in the microscopic perspective, and from a macro point of view, it is feasible method to describe degree of fatigue damage which bases on the changes of mechanical properties. In order to reflect the incremental cumulative damage degree of metal rubber, the stiffness damage and damping damage are used to accurately describe the fatigue damage process of metal robber, and the comprehensive damage factor is proposed to be the fatigue failure criterion. Damage factor can predict fatigue life of metal rubber specimen accurately, so it has reference significance to design of metal rubber

To meet the need of damping material at the marine corrosive environment, the clamped-edge disk type of metal rubber specimen is designed and its corrosion-load alternate experiment is performed, the anti-corrosive and damping characteristic of the material at the marine corrosive environment is researched. The experimental results show that the corrosive rate of 304 stainless steel metal rubber specimen at cycle-immersion corrosion-load alternate environment is the highest and its decay rate of dynamic average rigidity is also the highest, and followed by full-immersion, cycle-salt-spray and full-salt-spray environment. The damping characteristic of metal rubber specimen is relatively stable at the corrosion-load alternate experiment; the metal rubber material has anti-corrosion ability at marine environment.