Nonlinear Elastoplastic Analysis of Plates Coupled with Mechanical Element–Based Isolation System

Abstract

In general, the response of a system coupled with a vibration absorber is obtained by incorporating only elastic analysis under different loading conditions. However, the elastoplastic analysis is carried out for blast-resistant structures such as monolithic and composite sandwich panels. The present study delineates the nonlinear elastoplastic analysis of two steel plates sandwiched with mechanical elements (spring-dashpot-inerter)–based dynamic vibration absorber (DVA) subjected to a uniformly distributed blast load on one of its surfaces. The assembly of two steel plates interconnected with spring–dashpot elements is modeled as an equivalent two-degree-of-freedom (2DOF) system incorporating nonlinear elastoplastic material properties. The equivalent mass, resistance, and load are computed using transformation factors. The displacement response of the equivalent 2DOF system is compared with a finite element (FE)–based numerical model of the assembly. The influence of inserting an inerter between two plates is investigated by considering three configurations of dynamic vibration absorber and varying certain parameters such as stiffness, damping coefficient, and inertance. It was observed that in terms of deformation and force transmitted to the back plate, the configuration of the inerter in series with a dashpot element performed better than the simple spring–dashpot arrangement. The internal resistance of the front plate governs the performance of different configurations of DVA, which was demonstrated by changing the thicknesses of the plates. The influence of nonlinearity on the dynamics of the system was investigated.