Vibration extensively exists in various engineering practice, causing noise, discomfort, and even occupational diseases in workers or destruction to structures/machines. Dr Jing Xingjian at the Department of Mechanical Engineering explains how his newly developed bio-inspired nonlinear anti-vibration structure significantly reduces vibration in mechanic systems.
Please briefly introduce the basic concepts of vibration control.
There are two forms of vibration control, namely passive vibration control and active vibration control. The former isolates or mitigates vibration by passive techniques (such as the use of rubber pads, mechanical springs and shock absorbers); the latter applies force or energy in an equal and opposite fashion to the vibration force. In general, passive vibration control is most preferred in engineering practice as its manufacturing, operating and maintenance cost is much lower than active systems. It also consumes less energy, and is easier to repair, less complex and thus more reliable. However, the vibration control performance of active systems will usually be much better.
What gives the novel anti-vibration system an edge over conventional vibration control techniques?
Inspired by the principle of X-shaped limb structure of birds and insects, the PolyU X-shaped structure possesses the benefits of passive and active systems. It has superior nonlinear stiffness and damping characteristics which can suppress vibration transmission and absorb vibration energy dramatically. These advantages are lacking in most vibration control systems nowadays which usually follow the linear system design.
What are the applications of this anti-vibration system?
With support from the construction sector, we are applying this patented anti-vibration system in building an assistive anti-vibration exoskeleton for hand-held jackhammers. The new system can help prevent occupation diseases among construction workers due to hand-arm vibration. The vibration exerted on hand/arm in drilling concrete ground can be significantly suppressed to the ideal safety level. The manufacturing and maintenance costs of this system are very low. Also, its folding design offers great flexibility in adapting to devices of different sizes made by different materials, giving it potentials for popular usage.
What is your future plan in developing this system?
We are honoured to have won the TechConnect Global Innovation Awards 2017 with this invention and will continue to work on the system's further applications in robotics, railways, vehicle suspension, precise machines, offshore platforms, marine engineering, aeronautic engineering, and various civil structures like bridges and buildings.