Theoretical and experimental analysis of shock isolation using non linear stiffness

Abstract

Shock vibration is a common problem involving large forces and accelerations, usually resulting in nonlinear behavior. Normally shock isolation systems are modeled after linear passive stiffness elements intended to absorb the energy from the shock, and viscous damping in order to dissipate the energy. An experimental system with low dynamic stiffness is proposed and presented in this work, using a combination of positive stiffness and negative stiffness given by magnetic forces. The experimental prototype is based on a theoretical model involving a cubic restoring force. The results presented shown how such an isolator provides improved shock isolation, pointing out advantages and disadvantages.

A planar shock isolation system with high-static-low-dynamic-stiffness characteristic based on cables

“…Experimental results show that the HSLDS isolator has a greater isolation region and a lower peak response to base excitation than the equivalent linear system [14,22]. In fact, the isolator can also effectively be used for shock isolation [23], however, the researches on this aspect are seldom discussed. Liu [24] researched the response of the isolator for different shock severity parameters and found that it is beneficial to introduce a HSLDS isolator for shock excitations, but the performances are affected by the parameters and type of the shock excitation.…”