Potential benefits of a non-linear stiffness in an energy harvesting device

作者：Ramlan R^*; Brennan M J; Mace B R; Kovacic I

来源：Nonlinear Dynamics, 2010, 59(4): 545-558.

DOI：10.1007/s11071-009-9561-5

• Energy harvesting
• Snap-through
• Hardening
• Negative stiffness

The benefits of using a non-linear stiffness in an energy harvesting device comprising a mass-spring-damper system are investigated. Analysis based on the principle of conservation of energy reveals a fundamental limit of the effectiveness of any non-linear device over a tuned linear device for such an application. Two types of non-linear stiffness are considered. The first system has a non-linear bi-stable snap-through mechanism. This mechanism has the effect of steepening the displacement response of the mass as a function of time, resulting in a higher velocity for a given input excitation. Numerical results show that more power is harvested by the mechanism if the excitation frequency is much less than the natural frequency. The other non-linear system studied has a hardening spring, which has the effect of shifting the resonance frequency. Numerical and analytical studies show that the device with a hardening spring has a larger bandwidth over which the power can be harvested due to the shift in the resonance frequency.

• 出版日期2010-3