Dynamics study of a novel secretary bird inspired vibration isolator: modeling, analysis and experiment

In this paper, we propose and study a novel secretary bird inspired vibration isolator (SBIVI). Sensitive equipment and instruments in precision and aerospace engineering may suffer from vibration and their working performance would decrease a lot. The X-shaped structure vibration isolator with the quasi-zero stiffness (QZS) feature is the promising isolation device. However, vibration damping capability may be limited with the sole X-shaped vibration isolator. To this end, two independent pendulum-type vibration absorbers are introduced into the traditional X-shaped structure, inspired by the body of the secretary bird. The structure mapping from the secretary bird body to the SBIVI scheme is analyzed. The nonlinear dynamics model is constructed and then the numerical simulations are conducted. It is found that as the inertial length ratio increases, the nonlinear inertia and damping effects become stronger. The ADAMS-based virtual prototype simulations are carried out. The ADAMS simulation results show that the effective isolation frequency bandwidth of the secretary bird inspired vibration isolator is broader than that of the human body inspired where their resonant frequencies are 1.14 Hz and 1.21 Hz respectively. The overall experimental setup is built. It is shown experimentally that the proposed SBIVI can isolate the low frequency vibration and fast shock disturbance with different payload weights. Under the shock disturbance, the maximum vibration amplitude of the sole X-shaped structure is 5 mm, whereas that of the proposed SBIVI is reduced by one order of magnitude to 0.5 mm.