An adjustable device to adaptively realise diverse nonlinear force-displacement characteristics

The benefit of introducing nonlinear stiffness elements to improve the dynamic performance of vibration energy harvesters, vibration isolators and vibration absorbers have attracted great attention in the recent literature. A simple adjustable device to tailor nonlinear stiffness for diverse engineering applications is thus proposed in this paper. The device adopts two pairs of linear oblique springs, whose geometric arrangement can be modified to achieve specific nonlinear force-displacement characteristics. Depending on its design configuration, it is able to be adapted and behave as linear, hardening, softening, quasi-zero stiffness for large deflections, quasi-zero stiffness for small deflections, bi-stable and tri-stable. The design strategy and the main parameters involved are discussed.