Usually, the stiffness of the conventional isolator is small because the performance of vibration isolation is preferential to that of shock isolation. This leads to high efficiency of shock isolation but large relative displacement. Moreover, the stiffness break is induced by the displacement restrictor, and the efficiency of shock isolation is deteriorated. Based on the law of conservation of energy, the conventional shock isolator and the Ruzicka isolator is modeled and analyzed, and the cushioning coefficients are obtained. Comparison shows that the Ruzicka isolator has more excellent performance than that of the conventional isolator. The shock isolation system with the Ruzicka isolator is changed to the dimensionless form with an acceleration pulse input of half sine shape. The shock response is calculated, and the parameters with high efficiency of shock isolation are obtained. The shock response shows that the maximal acceleration and relative displacement are restricted below the limit value by the Ruzicka isolator when the conventional design fails to protect the object.

A new method that can apply DDAM to nonlinear stiffness system is put forward in the paper, an equivalent linear stiffness model with displacement restrictor is constructed, and the optimal scheme is designed. Pareto setting is obtained by finite element method and genetic algorithm, this pareto setting would be an excellent reference for engineering application. This design mode would assure excellent vibration and shock isolation at the same time, that is significative for vibration and shock isolation of onboard settings.