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金属橡胶(MR)材料由于其出色的阻尼性能广泛应用在各种减振、隔振、抗冲击结构系统中,掌握其失效判据和准确预测其耐久性是关系到整个系统能否安全可靠工作的重要问题。针对MR构件在静载荷持续作用下的失效判据和耐久性展开了试验研究。结果表明:从结构尺寸变化量和力学性能蜕变量2个方面定义MR的失效判定参数合理可行,通过确定阈值可判定MR是否失效并给定耐久寿命。随保载时间的增加,MR的失效评定参数(结构尺寸变化量和力学性能蜕变量)呈现明显的阶段性变化,能分别反映MR材料内部微观结构及受力状态随持续静载荷的变化。在本试验中,无论保载载荷大小,MR结构在总试验时间未表现出结构尺寸失效。而MR保载载荷的增大会显著削弱其力学性能耐久寿命,导致割线模量蜕变量过大,MR构件表现出力学性能的明显失效。
Due to its excellent damping properties, MR materials are widely used in a variety of vibration damping, vibration isolation and impact resistant structural systems. Mastering the failure criteria and accurately predicting the durability of MR materials are related to the safety and reliability of the whole system The important issue. Aiming at the failure criterion and durability of MR component under the action of static load, experimental research is carried out. The results show that it is reasonable and feasible to define MR failure determination parameters from two aspects of structure size variation and mechanical properties decay. By determining the threshold value, it can be judged whether MR is invalid or not and the life expectancy is given. With the increase of the holding time, the parameters of MR failure assessment (structural dimensional change and mechanical properties degradation) show obvious phase changes, which can reflect the changes of internal microstructure and stress state of MR with the steady static load respectively. In this test, regardless of the size of the ballast load, the MR structure did not show structural dimensional failure during the total test time. The increase of MR load will significantly weaken the mechanical properties of the durable life, resulting in the secant modulus of deformation is too large, MR members showed significant failure of the mechanical properties.