Dynamic behaviour of MDOF oscillators subjected to multiple visco-elastic contact constraints

Dynamic behaviour of multiple degree-of-freedom (MDOF) oscillators subjected to multiple gap-activated visco-elastic (VE) constraints is investigated in this paper. The complex problem is formulated to be a Linear Complementarity Problem (LCP) by means of the Newmark integration scheme and the incremental displacements. The proposed method is tested for a 2-mass oscillator with one mass subjected to a gap-activated VE constraint. Excellent agreement with the results available in the literature is achieved. The dynamical behaviour of a 2-mass and a 5-mass oscillator with all masses subjected to gap-activated VE constraints are then investigated. The bifurcation diagram for a range of frequency and excitation amplitude ratios is presented. The harmonic and sub-harmonic resonances and chaotic motion are accurately captured. The method is free from any prior assumption and can be used to simulate the dynamic behaviour of MDOF system with arbitrary number of constraints. (C) 2017 Elsevier Ltd. All rights reserved.