Abstract
The importance of simple and compact passive vibration isolator is increasingly growing owing to the demand for precision mechanical systems and measuring equipment. In particular, to suppress the vibration transmissibility for the vertical direction, nonlinear dynamic properties, which exhibit high static stiffness to support the weight of an isolated object and low tangent stiffness to reduce the natural frequency, are required. To realize such characteristics, the authors have proposed a nonlinear passive vibration isolator using the post-buckled L-shaped beam. However there is a problem that the second mode, which is dominated by rotational motion of the isolated object, is excited, and the transmissibility for vertical direction deteriorates. In this report, to suppress the excitation of undesirable mode, we propose a new model. Concretely, we newly propose isolation model, which is obtained by changing the direction of vertical beam to suppress the rotational motion of an isolation object, and investigate numerically and experimentally.
