Controllable properties of negative stiffness structures filled with magnetorheological fluids

Abstract Negative stiffness (NS) metamaterials have wide potential applications in vibration control due to their unique mechanical properties. A NS dome filled with Magnetorheological fluids (MRFs) was designed and fabricated, and its controllable performances were verified by theoretical analysis and simulation. Quasi-static compression experiments were conducted with different particle volume fractions of MRFs and magnetic field intensities. Experimental results show that the NS value and corresponding displacement interval of the structure can are tunable by the external magnetic field without changing the physical structure. The pressing force of the NS structure can be adjusted by the magnetic field due to the magnetorheological effect of MRFs. The absolute NS value and corresponding displacement interval decrease with the increase of magnetic field intensity. The NS value exhibits an approximately linear relationship with the magnetic field intensity. The controllable ratio of NS value and corresponding displacement interval are also affected by the particle volume fraction of MRFs, and both of them increase linearly to the increase of the particle volume fraction approximately. The NS controllable properties of the proposed structure can facilitate the design of quasi-zero stiffness isolators for precision vibration control.