はりの座屈を用いた非線形防振装置の性能向上に関する研究

抄録

The importance of passive vibration isolator is increasingly growing because of its stability of performance and lower cost. In the previous paper, the authors proposed a nonlinear passive isolator for vertical direction based on a post-buckled L-shaped beam, which consists of two thin plates, and the performance of the proposed isolator in post-buckled state of unstable buckling mode was numerically and experimentally investigated. Then, the following two undesirable characteristics were detected. Two resonance peaks, which correspond to the fundamental natural mode of the translational motion and the rotational motion of an isolated object, appear in low frequency range. The isolation range of the isolator is in the frequency range over the second natural frequency and the isolation performance is compromised by the presence of higher frequency internal resonances of the isolator. In this paper, we investigate the countermeasure against the second and higher natural modes to avoid the undesirable resonance. Concretely, we newly propose two isolation models to suppress the second and higher resonance and validity of proposed systems are numerically investigated.