Optimum Design of Elastomer-Based Shock Isolation System for a Naval Component

This paper aims to design a novel isolation system based on natural rubber (NR), polyurethane (PU), and Sorbothane for protecting a sensitive article kept within a naval vessel container (NVC) from a shock load.

First, NVC is analyzed using the MATLAB tool as an analytical model with two degrees of freedom, wherein the elastomer’s isolation system is modeled by nonlinear stiffness up to third-order and linear damping. The genetic algorithm determines optimal values of stiffness and damping parameters to minimize simultaneously both the maximum shock transfer to the sensitive article and the maximum deformation of the isolation system. Furthermore, the NVC’s 3D finite element model (FEM) is created in ABAQUS and exposed to the transverse shock load to perform an in-depth dynamic analysis of the isolation system. In the 3D FEM, the nonlinear elastic and time-dependent properties of the considered materials are defined based on test data using appropriate hyperelastic and viscoelastic models, respectively.

The 3D FEM results show that three isolators with lengths of 170 mm, 75 mm, and 500 mm each for NR, PU, and Sorbothane materials, respectively, are optimal. The NVC’s 3D simulation results for the optimal design of NR, PU, and Sorbothane isolators closely match the analytical model’s optimized results.

Moreover, the shock is reduced by 98.26%, 98.29%, and 98.49%, respectively, for NR, PU, and Sorbothane isolators with the maximum deformation of isolators below 10 mm, demonstrating the high effectiveness of the proposed design in shock mitigation.