Preliminary design, experiment, and numerical study of a prototype hydraulic bio-inspired damper

A series of studies with both numerical simulation and small laboratory experimental models of a bio-inspired damper which mimics the behavior of a bio-mechanism found in abalone shells, bones, and titin have been conducted. The results have been promising for various applications including cross-bracings, base-isolators, and tuned mass dampers for building frame structures for seismic damage mitigation. The small laboratory scale bio-inspired damper is in this study enhanced with increased force capacity using a hydraulic damper. A detailed description of the damper design is introduced, and its intermediate scale structural performance is studied by experimental validation and numerical simulation. The damper is mechanically tested on a linear electromagnetic stage at two different force settings of 800 N (180 lbF) under sinusoidal excitation inputs of 0.25 Hz and 0.5 Hz, and 400 N (90 lbF) at 0.25 Hz, 0.5 Hz and 1.0 Hz. The experimental results closely match the theoretical prediction of the damper with a consistent force output for these excitation frequencies. Furthermore, three numerical studies of the theoretical damper for an application in two automotive suspensions over sinusoidal road disturbance and a bump type road disturbance, and an application in a mountain bicycle suspension over bump type road disturbance are presented. In these illustrative numerical examples, the theoretical damper shows improved vibration reduction performance over traditional passive systems and performed comparably to the active and semi-active suspension systems. These studies provide examples of the versatility of the bio-inspired damper but more research is needed to validate the viability for physical applications. In particular, improved prototypes and testing at higher frequencies than were available will be needed.