In this study, variable stiffness elastic mechanism for the application to a vibration isolation system for precision motion mechanism was manufactured and its characteristics were evaluated. In order to understand the shear modulus and its variation as characteristics for vibration attenuation, magnetorheological elastomers based on a natural rubber matrix were fabricated and tested. Four types of carbonyl iron particles with different manufacturing methods were used, and the shear modulus and magnetorheological effects were measured by changing the volume fraction and applied magnetic field. A magnetorheological elastomer was manufactured by selecting carbonyl iron particles with high shear modulus and a large magnetorheological effect, and using this, a variable stiffness elastic mechanism with integrated electromagnets was manufactured. Variable stiffness characteristics of 3.67-6.75% were verified by testing the resonance frequency change according to the application of electromagnet current, and the thermal effect was experimentally observed.

본 연구에서는 정밀 모션기구 등의 제진 시스템에 적용하기 위한 가변강성 탄성기구를 제작하고 그 특성을 실험하였다. 진동 저감에 필요한 특성으로서 전단강성과 그 가변 정도를 파악하기 위해 천연고무 기지재 기반 자기유변탄성체를 제작하여 실험하였다. 혼입한 자기 응답성 입자는 입도 및 제조방식을 달리하는 4종의 카보닐 철을 사용하였으며, 자기장을 변경하며 전단강성 및 자기유변 효과를 측정하였다. 강성이 높고 자기유변 효과가 큰 입자를 선정하여 자기유변 탄성체를 제작하고, 이를 이용하여 전자석이 일체형으로 통합된 가변강성 탄성기구를 제작하였다. 전자석 전류 인가에 따른 공진주파수 변화를 실험하여 3.67-6.75% 가변강성 특성을 검증하였으며 전자석 구동에 따른 열적인 효과를 실험적으로 관찰하였다.

Keywords: magneto-rheological elastomer, natural rubber, carbonyl iron particle, variable stiffness.