Shock Isolation Through Translational-to-Rotational Energy Transference

The design of isolation mounts is of critical importance in the protection of structures and sensitive equipment from damage or failure. Simultaneous protection from both shock and vibration is particularly challenging because of the broadband nature of the input signal and because of the deleterious effect of damping on high-frequency isolation. Prior work by the authors has shown that chains of translating mass/spring elements can act as a “mechanical filter” for input disturbances. However, in finite-length chains, wave reflections can result in secondary pulses that hit the structure and can diminish the effectiveness of the isolator. In this paper, a new type of isolator is developed that converts translational input forces into a combination of translational and rotational motion. If designed correctly, the rotational motion can be managed so that it does not result in additional forces transmitted to the structure. In effect, the isolator is able to trap some of the input energy into rotational vibration, preventing it from reaching the structure. Parametric simulation studies are conducted as various system parameters are varied.