DESIGN AND TEST OF AN ADAPTIVE TUNED VIBRATION ABSORBER FOR REDUCING CRYOGENIC COOLER VIBRATIONS

摘要

The focuses of this study are to design an adaptive tuned vibration absorber based on a smart material known as magnetorheological elastomers (MRE) and to test its dynamic performance. A primary system replicating a cryogenic cooler was designed and fabricated in order to test the effectiveness of the vibration absorber. A hybrid magnetic system (electromagnet and permanent magnets) was also designed and fabricated in order to actuate the MRE as an adaptive stiffness element in the vibration absorber. Vibration testing was conducted on both the primary system and vibration absorber individually in order to characterize the behavior and verify the design constraints. Further testing was performed on the two degree of freedom system to measure and assess the feasibility of the MRE material for use in an application requiring an adaptive vibration absorber. The results show that by using a hybrid design for the electromagnet within the vibration absorber, the stiffness of the MRE material can be both increased and decreased above its nominal value; therefore demonstrating the feasibility of this design as an alternative adaptive vibration absorber.